Practice guidelines for managing extrahepatic biliary tract cancers

Backgrounds/Aims

Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021.

Methods

Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop.

Results

In November 2021, the finalized draft was presented for public scrutiny during a formal hearing.

Conclusions

The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

Prediction of Lymph Node Metastasis in T1 Colorectal Cancer Using Artificial Intelligence with Hematoxylin and Eosin-Stained Whole-Slide-Images of Endoscopic and Surgical Resection Specimens

According to the current guidelines, additional surgery is performed for endoscopically resected specimens of early colorectal cancer (CRC) with a high risk of lymph node metastasis (LNM). However, the rate of LNM is 2.1-25.0% in cases treated endoscopically followed by surgery, indicating a high rate of unnecessary surgeries. Therefore, this study aimed to develop an artificial intelligence (AI) model using H&E-stained whole slide images (WSIs) without handcrafted features employing surgically and endoscopically resected specimens to predict LNM in T1 CRC. To validate with an independent cohort, we developed a model with four versions comprising various combinations of training and test sets using H&E-stained WSIs from endoscopically (400 patients) and surgically resected specimens (881 patients): Version 1, Train and Test: surgical specimens; Version 2, Train and Test: endoscopic and surgically resected specimens; Version 3, Train: endoscopic and surgical specimens and Test: surgical specimens; Version 4, Train: endoscopic and surgical specimens and Test: endoscopic specimens. The area under the curve (AUC) of the receiver operating characteristic curve was used to determine the accuracy of the AI model for predicting LNM with a 5-fold cross-validation in the training set. Our AI model with H&E-stained WSIs and without annotations showed good performance power with the validation of an independent cohort in a single center. The AUC of our model was 0.758-0.830 in the training set and 0.781-0.824 in the test set, higher than that of previous AI studies with only WSI. Moreover, the AI model with Version 4, which showed the highest sensitivity (92.9%), reduced unnecessary additional surgery by 14.2% more than using the current guidelines (68.3% vs. 82.5%). This revealed the feasibility of using an AI model with only H&E-stained WSIs to predict LNM in T1 CRC.

Single-cell transcriptome analysis reveals subtype-specific clonal evolution and microenvironmental changes in liver metastasis of pancreatic adenocarcinoma and their clinical implications

BACKGROUND

Intratumoral heterogeneity (ITH) and tumor microenvironment (TME) of pancreatic ductal adenocarcinoma (PDAC) play important roles in tumor evolution and patient outcomes. However, the precise characterization of diverse cell populations and their crosstalk associated with PDAC progression and metastasis is still challenging.

METHODS

We performed single-cell RNA sequencing (scRNA-seq) of treatment-naïve primary PDAC samples with and without paired liver metastasis samples to understand the interplay between ITH and TME in the PDAC evolution and its clinical associations.

RESULTS

scRNA-seq analysis revealed that even a small proportion (22%) of basal-like malignant ductal cells could lead to poor chemotherapy response and patient survival and that epithelial-mesenchymal transition programs were largely subtype-specific. The clonal homogeneity significantly increased with more prevalent and pronounced copy number gains of oncogenes, such as KRAS and ETV1, and losses of tumor suppressor genes, such as SMAD2 and MAP2K4, along PDAC progression and metastasis. Moreover, diverse immune cell populations, including naïve SELLhi regulatory T cells (Tregs) and activated TIGIThi Tregs, contributed to shaping immunosuppressive TMEs of PDAC through cellular interactions with malignant ductal cells in PDAC evolution. Importantly, the proportion of basal-like ductal cells negatively correlated with that of immunoreactive cell populations, such as cytotoxic T cells, but positively correlated with that of immunosuppressive cell populations, such as Tregs.

CONCLUSION

We uncover that the proportion of basal-like subtype is a key determinant for chemotherapy response and patient outcome, and that PDAC clonally evolves with subtype-specific dosage changes of cancer-associated genes by forming immunosuppressive microenvironments in its progression and metastasis.

Establishment of a patient-specific avatar organoid model derived from endoscopic ultrasonography-guided fine needle biopsy for timely clinical application in pancreatic ductal adenocarcinoma

BACKGROUND AND AIMS

Pancreatic ductal adenocarcinoma (PDAC) has the worst survival rate among tumors. At the time of diagnosis, more than 80% of PDACs are considered to be surgically unresectable, and there is an unmet need for treatment options in these inoperable PDACs. This study aimed to establish a patient-derived organoid (PDO) platform from endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) collected at diagnosis and to determine its clinical applicability for the timely treatment of unresectable PDAC.

METHODS

Patients with suspected PDAC were prospectively enrolled at the Samsung Medical Center from 2015 to 2019. PDAC tissues were acquired by means of EUS-FNB to establish PDAC PDOs, which were comprehensively analyzed for histology, genomic sequencing, and high-throughput screening (HTS) drug sensitivity test.

RESULTS

PDAC PDOs were established with a success rate of 83.2% (94/113). It took approximately 3 weeks from acquiring minimal EUS-FNB specimens to generating sufficient PDAC PDOs for the simultaneous HTS drug sensitivity test and genomic sequencing. The high concordance between PDAC tissues and matched PDOs was confirmed, and whole-exome sequencing revealed the increased detection of genetic alterations in PDOs compared with EUS-FNB tissues. The HTS drug sensitivity test showed clinical correlation between the ex vivo PDO response and the actual chemotherapeutic response of the study patients in the real world (13 out of 15 cases). In addition, whole-transcriptome sequencing identified candidate genes associated with nab-paclitaxel resistance, such as ITGB7, ANPEP, and ST3GAL1.

CONCLUSIONS

This PDAC PDO platform allows several therapeutic drugs to be tested within a short time window and opens the possibility for timely personalized medicine as a "patient avatar model" in clinical practice.

Adenomyomas of the Gallbladder: An Analysis of Frequency, Clinicopathologic Associations, and Relationship to Carcinoma of a Malformative Lesion

CONTEXT.—

The nature and associations of gallbladder (GB) "adenomyoma" (AM) remain controversial. Some studies have attributed up to 26% of GB carcinoma to AMs.

OBJECTIVE.—

To examine the true frequency, clinicopathologic characteristics, and neoplastic changes in GB AM.

DESIGN.—

Cholecystectomy cohorts analyzed were 1953 consecutive cases, prospectively with specific attention to AM; 2347 consecutive archival cases; 203 totally embedded GBs; 207 GBs with carcinoma; and archival search of institutions for all cases diagnosed as AM.

RESULTS.—

Frequency of AM was 9.3% (19 of 203) in totally submitted cases but 3.3% (77 of 2347) in routinely sampled archival tissue. A total of 283 AMs were identified, with a female to male ratio = 1.9 (177:94) and mean size = 1.3 cm (range, 0.3-5.9). Most (96%, 203 of 210) were fundic, with formed nodular trabeculated submucosal thickening, and were difficult to appreciate from the mucosal surface. Four of 257 were multifocal (1.6%), and 3 of 257 (1.2%) were extensive ("adenomyomatosis"). Dilated glands (up to 14 mm), often radially converging to a point in the mucosa, were typical. Muscle was often minimal, confined to the upper segment. Nine of 225 (4%) revealed features of a duplication. No specific associations with inflammation, cholesterolosis, intestinal metaplasia, or thickening of the uninvolved GB wall were identified. Neoplastic change arising in AM was seen in 9.9% (28 of 283). Sixteen of 283 (5.6%) had mural intracholecystic neoplasm; 7 of 283 (2.5%) had flat-type high-grade dysplasia/carcinoma in situ. Thirteen of 283 cases had both AM and invasive carcinoma (4.6%), but in only 5 of 283 (1.8%), carcinoma arose from AM (invasion was confined to AM, and dysplasia was predominantly in AM).

CONCLUSIONS.—

AMs have all the features of a malformative developmental lesion, and may not show a significant muscle component (ie, the name "adeno-myoma" is partly a misnomer). While most are innocuous, some pathologies may arise in AMs, including intracholecystic neoplasms, flat-type high-grade dysplasia or carcinoma in situ, and invasive carcinoma (1.8%, 5 of 283). It is recommended that gross examination of GBs include serial slicing of the fundus for AM detection and total submission if one is found.

Clinical Practice Recommendations for the Use of Next-Generation Sequencing in Patients with Solid Cancer: A Joint Report from KSMO and KSP

In recent years, next-generation sequencing (NGS)-based genetic testing has become crucial in cancer care. While its primary objective is to identify actionable genetic alterations to guide treatment decisions, its scope has broadened to encompass aiding in pathological diagnosis and exploring resistance mechanisms. With the ongoing expansion in NGS application and reliance, a compelling necessity arises for expert consensus on its application in solid cancers. To address this demand, the forthcoming recommendations not only provide pragmatic guidance for the clinical use of NGS but also systematically classify actionable genes based on specific cancer types. Additionally, these recommendations will incorporate expert perspectives on crucial biomarkers, ensuring informed decisions regarding circulating tumor DNA panel testing.

Prognostic Significance of Cyclin D1 Expression in Small Intestinal Adenocarcinoma

Cyclin D1, a critical cyclin-dependent kinase (CDK) 4/6-dependent regulator of G1/S transition, has attracted much interest as a therapeutic target. The cyclin D1 expression in small intestinal adenocarcinomas (SIACs) has not yet been comprehensively studied, owing to the rarity of this tumor. We investigated the clinicopathological and prognostic significance of the cyclin D1 expression in 232 surgically resected primary SIACs through a multi-institutional study. A high expression of cyclin D1 (cyclin D1High) was detected in 145 SIAC cases (63%), which was significantly higher than that in normal small intestinal mucosa (11%). Cyclin D1High was more commonly found in SIACs with a lower T-category and disease stage and KRAS mutation and predicted better patient survival. Multivariate analysis revealed that cyclin D1High, the absence of retroperitoneal seeding and lymphovascular invasion, and the lower N-category were identified as independent prognostic indicators for patients with SIACs. Specifically, cyclin D1High affected patient survival in the lower stage group (stages I and II). In conclusion, cyclin D1 was commonly overexpressed in SIACs, and cyclin D1High acted as a favorable prognostic indicator in patients with SIACs. These findings in SIACs may, thus, be important to further comprehend the mechanism of cyclin D1 in carcinogenesis and to strategize appropriate patient therapies.

Intraductal papillary neoplasm of the bile duct: review of updated clinicopathological and imaging characteristics

BACKGROUND

Intraductal papillary neoplasm of the bile duct (IPNB) is a relatively rare disease and is known as one of the premalignant lesions in the biliary tract. The concept of IPNB has changed through numerous studies and is still evolving. As a lesser studied clinical entity compared with its pancreatic counterpart, intraductal papillary mucinous neoplasm, IPNB has been described in many similar terms, including biliary papillomatosis, biliary intraductal papillary-mucinous neoplasm, and papillary cholangiocarcinoma. This is based on the diversity of histopathological spectrum of IPNB.

METHODS

This review investigated previous studies including original articles, case studies, and expert opinions. Recently, two types of IPNB (types 1 and 2) have been proposed and validated based on the content first established in the WHO 2010 criteria.

RESULTS

This review provides a comprehensive analysis of existing literature, summarizing the clinical, radiological, morphological, and pathological characteristics of IPNB.

CONCLUSION

Given the ongoing ambiguity and controversies surrounding IPNB, future research, including large population-based studies and molecular investigations, is essential to enhance understanding of this disease.

Clinicopathologic significance of the delta-like ligand 4, vascular endothelial growth factor, and hypoxia-inducible factor-2α in gallbladder cancer

BACKGROUND

Gallbladder cancer (GBC) is usually detected in advanced stages with a low 5-year survival rate. Delta-like ligand 4 (DLL4), vascular endothelial growth factor (VEGF), and hypoxia-inducible factor-2alpha (HIF2α) have been studied for their role in tumorigenesis and potential for therapeutic target, and multiple clinical trials of the agents targeting them are ongoing. We investigated the expression of these markers in surgically resected GBC and tried to reveal their association with the clinicopathologic features, mutual correlation of their expression, and prognosis of the GBC patients by their expression.

METHODS

We constructed the tissue microarray blocks of 99 surgically resected GBC specimens and performed immunohistochemistry of DLL4, VEGF, and HIF2α. We used the quantitative digital image analysis to evaluate DLL4 and VEGF expression, while the expression of HIF2α was scored manually.

RESULTS

The expression of VEGF and HIF2α showed a significant trend with tumor differentiation (p= .028 and p= .006, respectively). We found that the high DLL4 and VEGF expression were significantly correlated with lymph node metastasis (p= .047, both). The expression of VEGF and HIF2α were significantly correlated (p < .001). The GBC patients with low HIF2α expression showed shorter recurrence-free survival than those with high HIF2α expression.

CONCLUSIONS

This study suggested the possibility of the usage of DLL4 and VEGF to predict the lymph node metastasis and the possibility of VEGF and HIF2α to predict the expression level mutually. Further studies may be needed to validate our study results and eventually accelerate the introduction of the targeted therapy in GBC.

Detecting Donor-Derived DNA by Real-Time PCR in Recipients Suspected of Graft-Versus-Host-Diseases After Liver Transplantation: A Case Series and Literature Review

BACKGROUND Graft-versus-host disease (GVHD) after liver transplantation (LT) is a rare but fatal complication. GVHD diagnosis is usually based on clinical symptoms and pathologic confirmation. However, it is often misdiagnosed due to its non-specific symptoms. Here, we report the detection of donor-cell chimerism using peripheral blood (PB) donor-derived deoxyribonucleic acid (ddDNA) for 3 cases with suspected GVHD after LT (GVHD-LT) through real-time quantitative polymerase chain reaction (qPCR) assay targeting 39 insertions and/or deletions of chromosomes. MATERIAL AND METHODS The qPCR assay for detecting donor-cell chimerism was performed for 3 post-LT patients with suspected GVHD using KMRtype® and KMRtrack® assays (GenDx, Netherlands). The mean recipient/donor-cell fraction of informative markers unique to each recipient or donor was calculated. RESULTS In Case 1, who received living donor LT (LDLT) from his daughter, initial sign was diarrhea at post-operative day (POD) #23. Case 2 received unrelated deceased donor LT and initial sign was cytopenia at POD #29. Case 3 received LDLT from her son and GVHD associated cytopenia was developed at POD #80. Average PB ddDNA fractions in post-transplant samples of cases 1, 2, and 3 were 39.68%, 78.38%, and 4.76%, respectively. Despite an active treatment including steroid and tumor necrosis factor-alpha inhibitor, 2 patients (cases 1 and 2) died due to multiple organ failures. CONCLUSIONS Early detection of donor-cell chimerism may help halt fatal progression of GVHD-LT. A qPCR test targeting INDEL of chromosomes would be a helpful procedure for timely diagnosis of GVHD.

Comprehensive immunoprofile analysis of prognostic markers in pancreaticobiliary tract cancers

Pancreaticobiliary tract cancer has a poor prognosis with unmet needs in a new target treatment. Some studies have reported that an enhancement of T-cell immunity is associated with a good prognosis. The aim of this study is to investigate the immunoprofile as a prognostic marker of pancreaticobiliary tract cancers. Unresectable pancreatic ductal adenocarcinoma (PDAC, n = 80) and biliary tract cancer (BTC, n = 74) diagnosed between January 2012 and December 2018 in Samsung Medical Center were analyzed. Expression levels of CD8, FOXP3, PD-1, PD-L1, and CXCL13 in PDAC and BTC tissue samples were examined with immunohistochemical staining, which was evaluated with various clinical factors. In PDAC, higher degree of PD-L1 expression was significantly associated with shorter overall survival (OS) (p = 0.0095). On the other hand, higher infiltrations of PD-1⁺ immune cells (p = 0.0002) and CD8⁺ T cells (p = 0.0067) were associated with longer OS. In BTC, higher FOXP3⁺ (p = 0.0343) and CD8⁺ (p = 0.0028) cell infiltrations were associated with better survival. Low infiltration of CD8⁺ (p = 0.0148), FOXP3⁺ (p = 0.0208), PD-1⁺ (p = 0.0318) cells in PDAC, and FOXP3⁺ cells (p = 0.005) in BTC were considerably related to metastasis. In a combined evaluation of clinical factors and immunoprofiles, univariate analysis revealed that operation after chemotherapy (p < 0.0001), mass size (p = 0.0004), metastasis (p = 0.006), PD-L1 (p < 0.0001), PD-1 (p = 0.003) and CD8 (p = 0.0063) was significantly associated with OS in PDAC, and CD8 (p = 0.007) was statistically related to OS in BTC. In multivariate analysis, prognostic factors were operation after chemotherapy (p = 0.021) in PDAC and CD8 (p = 0.037) in BTC. Therefore, immunoprofile analysis of cells expressing CD8, FOXP3, PD-1, and PD-L1 might have prognostic values in patients with pancreaticobiliary tract cancers.

Postoperative Prognostic Predictors of Bile Duct Cancers: Clinical Analysis and Immunoassays of Tissue Microarrays

Background/Aims

Cholangiocarcinoma frequently recurs even after curative resection. Expression levels of proteins such as epidermal growth factor receptor (EGFR), Snail, epithelial cadherin (E-cadherin), and interleukin-6 (IL-6) examined by immunohistochemistry have been studied as potential prognostic factors for cholangiocarcinoma. The aim of this study was to investigate significant factors affecting the prognosis of resectable cholangiocarcinoma.

Methods

Ninety-one patients who underwent surgical resection at Samsung Medical Center for cholangiocarcinoma from 1995 to 2013 were included in this study. Expression levels of E-cadherin, Snail, IL-6, membranous EGFR, and cytoplasmic EGFR were analyzed by immunohistochemistry using tissue microarray blocks made from surgical specimens.

Results

Patients with high levels of membranous EGFR in tissue microarrays had significantly shorter overall survival (OS) and disease-free survival (DFS): high membranous EGFR (score 0-2) 38.0 months versus low membranous EGFR (score 3) 14.4 months (p=0.008) and high membranous EGFR (score 0-2) 23.2 months versus low membranous EGFR (score 3) 6.1 months (p=0.004), respectively. On the other hand, E-cadherin, Snail, cytoplasmic EGFR, and IL-6 did not show significant association with OS or DFS. Patients with distant metastasis had significantly higher IL-6 levels than those with locoregional recurrence (p=0.01).

Conclusions

This study showed that overexpression of membranous EGFR was significantly associated with shorter OS and DFS in surgically resected bile duct cancer patients. In addition, higher IL-6 expression was a predictive marker for recurrence in cholangiocarcinoma patients with distant organ metastasis after surgical resection.

Molecular characterization of onychomatricoma: Spatial profiling reveals the role of onychofibroblasts in its pathogenesis

Onychomatricoma (OM) is a rare nail unit tumour with a characteristic presentation of finger-like projections arising from the nail matrix. Due to the lack of transcriptome information, the mechanisms underlying its development are largely unknown. To characterize molecular features involved in the disease pathogenesis, we used digital spatial profiling (DSP) in 2 cases of OM and normal control nail units. Based on the histological evaluation, we selectively profiled 69 regions of interest covering epithelial and stromal compartments of each tissue section. Dermoscopic and histopathologic findings were reviewed in 6 cases. Single-cell RNA sequencing of nail units and DSP were combined to define cell type contributions of OM. We identified 173 genes upregulated in stromal compartments of OM compared to onychodermis, specialized nail mesenchyme. Gene ontology analysis of the upregulated genes suggested the role of Wnt pathway activation in OM pathogenesis. We also found PLA2G2A, a known modulator of Wnt signalling, is strongly and specifically expressed in the OM stroma. The potential role of Wnt pathway was further supported by strong nuclear localization of β-catenin in OM. Compared to the nail matrix epithelium, only a few genes were increased in OM epithelium. Deconvolution of nail unit cell types showed that onychofibroblasts are the dominant cell type in OM stroma. Altogether, integrated spatial and single-cell multi-omics concluded that OM is a tumour that derives a significant proportion of its origin from onychofibroblasts and is associated with upregulation of Wnt signals, which play a key role in the disease pathogenesis.

Comparative Spatial Transcriptomic and Single-Cell Analyses of Human Nail Units and Hair Follicles Show Transcriptional Similarities between the Onychodermis and Follicular Dermal Papilla

The nail unit and hair follicle are both hard keratin-producing organs that share various biological features. In this study, we used digital spatial profiling and single-cell RNA sequencing to define a spatially resolved expression profile of the human nail unit and hair follicle. Our approach showed the presence of a nail-specific mesenchymal population called onychofibroblasts within the onychodermis. Onychodermis and follicular dermal papilla both expressed Wnt and bone morphogenetic protein signaling molecules. In addition, nail matrix epithelium and hair matrix showed very similar expressions profile, including the expression of hard keratins and HOXC13, a transcriptional regulator of the hair shaft. Integration of single-cell RNA sequencing and digital spatial profiling data through computational deconvolution methods estimated epithelial and mesenchymal cell abundance in the nail- and hair-specific regions of interest and revealed close transcriptional similarity between these major skin appendages. To analyze the function of bone morphogenetic proteins in nail differentiation, we treated cultured human nail matrix keratinocytes with BMP5, which are highly expressed by onychofibroblasts. We observed increased expressions of hard keratin and its regulator genes such as HOXC13. Collectively, our data suggest that onychodermis is the counterpart of dermal papilla and that BMP5 in onychofibroblasts plays a key role in the differentiation of nail matrix keratinocytes.

Pathologic Examination of Pancreatic Specimens Resected for Treated Pancreatic Ductal Adenocarcinoma: Recommendations From the Pancreatobiliary Pathology Society

Currently, there are no internationally accepted consensus guidelines for pathologic evaluation of posttherapy pancreatectomy specimens. The Neoadjuvant Therapy Working Group of Pancreatobiliary Pathology Society was formed in 2018 to review grossing protocols, literature, and major issues and to develop recommendations for pathologic evaluation of posttherapy pancreatectomy specimens. The working group generated the following recommendations: (1) Systematic and standardized grossing and sampling protocols should be adopted for pancreatectomy specimens for treated pancreatic ductal adenocarcinoma (PDAC). (2) Consecutive mapping sections along the largest gross tumor dimension are recommended to validate tumor size by histology as required by the College of American Pathologists (CAP) cancer protocol. (3) Tumor size of treated PDACs should be measured microscopically as the largest dimension of tumor outer limits that is bound by viable tumor cells, including intervening stroma. (4) The MD Anderson grading system for tumor response has a better correlation with prognosis and better interobserver concordance among pathologists than does the CAP system. (5) A case should not be classified as a complete response unless the entire pancreas, peripancreatic tissues, ampulla of Vater, common bile duct, and duodenum adjacent to the pancreas are submitted for microscopic examination. (6) Future studies on tumor response of lymph node metastases, molecular and/or immunohistochemical markers, as well as application of artificial intelligence in grading tumor response of treated PDAC are needed. In summary, systematic, standardized pathologic evaluation, accurate tumor size measurement, and reproducible tumor response grading to neoadjuvant therapy are needed for optimal patient care. The criteria and discussions provided here may provide guidance towards these goals.

Comparative analysis of microsatellite instability by next-generation sequencing, MSI PCR and MMR immunohistochemistry in 1942 solid cancers

Checkpoint inhibitor approval for microsatellite instability-high (MSI-H) tumours has made MSI as a therapeutically important biomarker. Next-generation sequencing (NGS)-based MSI detection is being widely used for assessing MSI. However, MSI tumours detected using NGS and their relevance to MSI-polymerase chain reaction (PCR) and mismatch repair deficiency (dMMR) are unclear. In 1942 solid cancer cases tested using NGS-based comprehensive cancer panel with 523 genes (1.94 mb), the MSI score, tumour mutation burden (TMB; ≥ 10 mutations/mb), and frameshift mutations were analysed. GeneScan analyses of five mononucleotide markers (MSI-PCR) and MMR protein immunohistochemistry (IHC) were compared with the NGS-MSI results. With a ≥ 12% MSI score as a cut-off for MSI-H, two MSS cases were classified as MSI-H. With a ≥ 20% cut-off, 10 cases categorised as MSS by NGS were MSI-H/dMMR by MSI-PCR and MMR IHC. To avoid discrepant cases, we adopted a high MSI cut-off and a borderline MSI category. Finally, MSI-H (≥ 20%), borderline MSI (≥ 7% and < 20%), and MSS (< 7%) were found in 35 (1.8%), 24 (1.2%), and 1883 (97%) cases, respectively. All MSI-H cases by NGS were MSI-H/dMMR by MSI-PCR and MMR IHC. Of the 24 borderline MSI cases by NGS, MSI-H/dMMR was 9 (37.5%) cases, MSS/dMMR was 1 (4.2%) case, and 11 (45.8%) of them had high TMB. All MSS cases by NGS were MSS/pMMR by MSI-PCR/IHC, and 257 (13.6%) had high TMB. With those arbitrary cut-off points, 10 (0.5%) MSS cases using NGS were discrepant with MSI-PCR or MMR IHC, and all were borderline MSI cases. The mean number of frameshift mutations was significantly higher in the MSI-H group (28.3) than in the borderline MSI (7.7) or MSS (1.3) groups (p < 0.001). In conclusion, to facilitate therapeutic decision-making for NGS, cut-off points for MSI can be defined based on MSI-PCR/dMMR confirmation.

Direct comparison of the next-generation sequencing and iTERT PCR methods for the diagnosis of TERT hotspot mutations in advanced solid cancers

Background

Mutations in the telomerase reverse transcriptase (TERT) promoter region have been proposed as novel mechanisms for the transcriptional activation of telomerase. Two recurrent mutations in the TERT promoter, C228T and C250T, are prognostic biomarkers. Herein, we directly compared the commercially available iTERT PCR kit with NGS-based deep sequencing to validate the NGS results and determine the analytical sensitivity of the PCR kit.

Methods

Of the 2032 advanced solid tumors diagnosed using the TruSight Oncology 500 NGS test, mutations in the TERT promoter region were detected in 103 cases, with 79 cases of C228T, 22 cases of C250T, and 2 cases of C228A hotspot mutations. TERT promoter mutations were detected from 31 urinary bladder, 19 pancreato-biliary, 22 hepatic, 12 malignant melanoma, and 12 other tumor samples.

Results

In all 103 TERT-mutated cases detected using NGS, the same DNA samples were also tested with the iTERT PCR/Sanger sequencing. PCR successfully verified the presence of the same mutations in all cases with 100% agreement. The average read depth of the TERT promoter region was 320.4, which was significantly lower than that of the other genes (mean, 743.5). Interestingly, NGS read depth was significantly higher at C250 compared to C228 (p < 0.001).

Conclusions

The NGS test results were validated by a PCR test and iTERT PCR/Sanger sequencing is sensitive for the identification of the TERT promoter mutations.

Pancreatic ductal adenocarcinomas associated with intraductal papillary mucinous neoplasms (IPMNs) versus pseudo-IPMNs: relative frequency, clinicopathologic characteristics and differential diagnosis

The literature is highly conflicted on what percentage of pancreatic ductal adenocarcinomas (PDACs) arise in association with intraductal papillary mucinous neoplasms (IPMNs). Some studies have claimed that even small (Sendai-negative) IPMNs frequently lead to PDAC. Recently, more refined pathologic definitions for mucin-lined cysts were provided in consensus manuscripts, but so far there is no systematic analysis regarding the frequency and clinicopathologic characteristics of IPMN-mimickers, i.e., pseudo-IPMNs. In this study, as the first step in establishing frequency, we performed a systematic review of the pathologic findings in 501 consecutive ordinary PDACs, which disclosed that 10% of PDACs had associated cysts ≥1 cm. While 31 (6.2%) of these were IPMN or mucinous cystic neoplasm (MCN), 19 (3.8%) were other cyst types that mimicked IPMN (pseudo-IPMNs) per recent WHO/consensus criteria. As the second step of the study, we performed a comparative clinicopathologic analysis by also including our entire surgical pathology/consultation databases that was comprised of 60 IPMN-associated PDACs, 30 MCN-associated PDACs and 40 pseudo-IPMN-associated PDACs. We found that 84% of true IPMNs were pre-operatively recognized, whereas IPMN was considered in differential diagnosis of 33% of pseudo-IPMNs. Of the 40 pseudo-IPMNs, there were 15 secondary duct ectasias; 6 large-duct-type PDACs; 5 pseudocysts; 5 cystic tumor necrosis; 4 simple mucinous cysts; 3 groove pancreatitis-associated paraduodenal wall cysts; and 2 congenital cysts. Microscopically, pseudo-IPMNs had at least partial mucinous-lining mimicking IPMN but had smaller cystic (mean = 1.9 cm) and larger PDAC (mean = 3.8 cm) components compared to true IPMNs (cyst = 5.7 cm; PDAC = 2.0 cm). In summary, in this pathologically verified analysis that utilized refined criteria, 10% of PDACs were discovered to have cysts ≥1 cm, about two-thirds of which were IPMN/MCN but about one-third were pseudo-IPMNs. True IPMNs underlying the PDACs are often large and are already diagnosed pre-operatively as having an IPMN component, whereas only a third of the pseudo-IPMNs receive IPMN diagnosis by imaging and their cysts are smaller. At the histopathologic level, pseudo-IPMNs are highly prone to misdiagnosis as IPMN, which presumably accounts for much higher association of IPMNs with PDAC as reported in some studies. The subtle but salient characteristics of pseudo-IPMNs elucidated in this study should be combined with careful radiological/clinical correlation in order to exclude pseudo-IPMNs.

Towards a More Standardized Approach to Pathologic Reporting of Pancreatoduodenectomy Specimens for Pancreatic Ductal Adenocarcinoma: Cross-continental and Cross-specialty Survey From the Pancreatobiliary Pathology Society Grossing Working Group

In recent literature and international meetings held, it has become clear that there are significant differences regarding the definition of what constitutes as margins and how best to document the pathologic findings in pancreatic ductal adenocarcinoma. To capture the current practice, Pancreatobiliary Pathology Society (PBPS) Grossing Working Group conducted an international multispecialty survey encompassing 25 statements, regarding pathologic examination and reporting of pancreatic ductal adenocarcinoma, particularly in pancreatoduodenectomy specimens. The survey results highlighted several discordances; however, consensus/high concordance was reached for the following: (1) the pancreatic neck margin should be entirely submitted en face, and if tumor on the slide, then it is considered equivalent to R1; (2) uncinate margin should be submitted entirely and perpendicularly sectioned, and tumor distance from the uncinate margin should be reported; (3) all other surfaces (including vascular groove, posterior surface, and anterior surface) should be examined and documented; (4) carcinoma involving separately submitted celiac axis specimen should be staged as pT4. Although no consensus was achieved regarding what constitutes R1 versus R0, most participants agreed that ink on tumor or at and within 1 mm to the tumor is equivalent to R1 only in areas designated as a margin, not surface. In conclusion, this survey raises the awareness of the discordances and serves as a starting point towards further standardization of the pancreatoduodenectomy grossing and reporting protocols.

PD-L1 Expression Is Significantly Associated with Tumor Mutation Burden and Microsatellite Instability Score

Simple Summary

Biomarkers for predicting the response to immune checkpoint blockade (ICB) includes programmed death-ligand 1 (PD-L1) immunohistochemistry (IHC), microsatellite instability (MSI), and tumor mutation burden (TMB). This study investigated the relationship of these biomarkers using comprehensive cancer panel assay (CCPA) with >500 genes in 588 advanced cancer patients. The work demonstrates that PD-L1 expression is significantly associated with TMB and MSI score, according to primary tumor origin.

Abstract

Programmed death-ligand 1 (PD-L1) immunohistochemistry (IHC), microsatellite instability (MSI), and tumor mutation burden (TMB) have been proposed as a predictive biomarker to predict response to immune checkpoint blockade (ICB). We aimed to find the relationship of PD-L1 IHC to TMB and MSI using a comprehensive cancer panel assay (CCPA) with >500 genes in advanced cancer patients. CCPA results from 588 archived tissue samples were analyzed for TMB and MSI. In seven samples, whole exome sequencing confirmed TMB with Pearson’s correlation coefficient of 0.972 and all MSI-high cases were validated by pentaplex PCR. Association of TMB and MSI with their corresponding PD-L1 IHC was analyzed. The median TMB value of 588 cases was 8.25 mutations (mut)/Mb (range 0–426.8) with different distributions among the tumor types, with high proportions of high-TMB (>10mut/Mb) in tumors from melanoma, colorectal, gastric, and biliary tract. The TMB values significantly correlated with PD-L1 expression, and this correlation was prominent in gastric and biliary tract cancers. Moreover, the MSI score, the proportion of unstable MSI sites to total assessed MSI sites, showed a significant correlation with the TMB values and PD-L1 scores. This study demonstrates that PD-L1 expression is significantly associated with TMB and MSI score and this correlation depends on the location of the primary tumor.

Factors of Endoscopic Ultrasound-Guided Tissue Acquisition for Successful Next-Generation Sequencing in Pancreatic Ductal Adenocarcinoma

Background/Aims

Recent advances in understanding the genetics of pancreatic ductal adenocarcinoma (PDAC) have led to the potential for a personalized approach. Several studies have described the feasibility of generating genetic profiles of PDAC with next-generation sequencing (NGS) of samples obtained through endoscopic ultrasound-guided tissue acquisition (EUS-TA). The aim of this study was to find the best EUS-TA approach for successful NGS of PDAC.

Methods

We attempted to perform NGS with tissues from 190 patients with histologically proven PDAC by endoscopic ultrasound-guided fine-needle aspiration and endoscopic ultrasound-guided fine-needle biopsy at Samsung Medical Center between November 2011 and February 2015. The medical records of these patients were retrospectively reviewed for parameters including tumor factors (size, location, and T stage), EUS-TA factors (needle gauge [G], needle type, and number of needle passes) and histologic factors (cellularity and blood contamination). The sample used for NGS was part of the EUS-TA specimen that underwent cytological and histological analysis.

Results

NGS could be successfully performed in 109 patients (57.4%). In the univariate analysis, a large needle G (p=0.003) and tumor located in the body/tail (p=0.005) were associated with successful NGS. The multivariate logistic regression analysis revealed that the needle G was an independent factor of successful NGS (odds ratio, 2.19; 95% confidence interval, 1.08 to 4.47; p=0.031).

Conclusions

The needle G is an independent factor associated with successful NGS. This finding may suggest that the quantity of cells obtained from EUS-TA specimens is important for successful NGS.

Characterization of the Onychomatricodermis Containing Onychofibroblasts of the Nail Unit : Histology, Immunohistochemistry, and Electron Microscopic Study

BACKGROUND

We recently discovered the presence of specialized nail mesenchyme below the nail matrix and designated it as onychomatricodermis.

OBJECTIVE

We did further research to characterize the histologic, histochemical, immunohistochemical and ultrastructural features of the onychomatricodermis containing onychofibroblasts in the nail unit.

METHODS

Ten polydactyly nail unit specimens and 8 nail matrix biopsies were included. H&E-stained slides were reviewed. We did Alcian blue staining and Masson Trichrome staining, as well as immunohistochemical staining for type I collagen, CD10, CD13 and CD34. In addition, polydactyly nail units were examined by transmission electron microscopy.

RESULTS

In H&E staining, the specialized mesenchyme called onychomatricodermis was observed to be slightly distant from the undersurface of the nail matrix and be less eosinophilic area. Onychomatricodermal onychofibroblasts showed light purple abundant cytoplasm. Masson Trichrome staining revealed fewer collagen fibers within the onychomatricodermis. In Alcian blue staining the onychomatricodermis showed mucin deposition within the onychofibroblasts and around them. Immunohistochemically, type I collagen was expressed much less in the onychomatricodermis while it was strongly expressed elsewhere in the nail unit. In nail matrix biopsy specimens onychomatricodermal onychofibroblasts expressed CD10 and CD13 strongly, and expressed CD34 as well. Ultrastructurally, collagen fibrils were found sparsely within the onychomatricodermis, whereas collagen fibrils were densely distributed in the dermis of other parts of the nail unit.

CONCLUSION

We demonstrated that there was less collagen expression in the onychomatricodermis containing onychofibroblasts. In addition, we found morphological and immunohistochemical features of onychomatricodermal onychofibroblasts (onychofibroblasts of Dongyoun). These findings support the presence of onychomatricodermis containing onychofibroblasts in the nail unit.

Programmed Death Ligand 1 Expression as a Prognostic Marker in Patients with Advanced Biliary Tract Cancer

BACKGROUND

Biliary tract cancer (BTC) is associated with poor prognosis because of its aggressive and heterogeneous nature. Programmed death ligand 1 (PD-L1) has been considered a novel biomarker for prognosis and response of immune checkpoint inhibitors in various tumors. However, there are limited data reporting on the role of PD-L1 in advanced BTC patients.

PATIENTS AND METHODS

We analyzed 186 patients with advanced BTC who received palliative gemcitabine and platinum between May 2010 and December 2019. All patients were evaluated for PD-L1 expression by combined positive score positivity.

RESULTS

Of the 186 patients, the primary tumor location was intrahepatic cholangiocarcinoma (IHCC) in 72 (38.7%), extrahepatic cholangiocarcinoma (EHCC) in 90 (48.4%), and gallbladder (GB) cancer in 24 (12.9%). Among all the patients, 53 (28.5%) had PD-L1 positivity. The median overall survival (OS) of patients with PD-L1 positivity or negativity was 12.1 and 15.4 months, respectively. The median progression-free survival (PFS) in patients with PD-L1 positivity or negativity was 5.7 and 7.1 months, respectively. OS and PFS were not statistically different between groups. In subgroup analysis, EHCC patients with PD-L1 negativity had more favorable OS (17.2 vs. 11.6 months, p = 0.002) and PFS (7.8 vs. 5.4 months, p = 0.005) than those who were PD-L1-positive. However, this finding was not reproduced in patients with IHCC or GB cancer.

CONCLUSION

This study demonstrated that PD-L1 expression might be a novel prognostic biomarker in patients with EHCC but not in patients with IHCC or GB cancer.

T2 gallbladder cancer shows substantial survival variation between continents and this is not due to histopathologic criteria or pathologic sampling differences

Published data on survival of T2 gallbladder carcinoma (GBC) from different countries show a wide range of 5-year survival rates from 30-> 70%. Recently, studies have demonstrated substantial variation between countries in terms of their approach to sampling gallbladders, and furthermore, that pathologists from different continents apply highly variable criteria in determining stage of invasion in this organ. These findings raised the question of whether these variations in pathologic evaluation could account for the vastly different survival rates of T2 GBC reported in the literature. In this study, survival of 316 GBCs from three countries (Chile n = 137, South Korea n = 105, USA n = 74), all adequately sampled (with a minimum of five tumor sections examined) and histopathologically verified as pT2 (after consensus examination by expert pathologists from three continents), was analyzed. Chilean patients had a significantly worse prognosis based on 5-year all-cause mortality (HR: 1.89, 95% CI: 1.27-2.83, p = 0.002) and disease-specific mortality (HR: 2.41, 95% CI: 1.51-3.84, p < 0.001), compared to their South Korean counterparts, even when controlled for age and sex. Comparing the USA to South Korea, the survival differences in all-cause mortality (HR: 1.75, 95% CI: 1.12-2.75, p = 0.015) and disease-specific mortality (HR: 1.94, 95% CI: 1.14-3.31, p = 0.015) were also pronounced. The 3-year disease-specific survival rates in South Korea, the USA, and Chile were 75%, 65%, and 55%, respectively, the 5-year disease-specific survival rates were 60%, 50%, and 50%, respectively, and the overall 5-year survival rates were 55%, 45%, and 35%, respectively. In conclusion, the survival of true T2 GBC in properly classified cases is neither as good nor as bad as previously documented in the literature and shows notable geographic differences even in well-sampled cases with consensus histopathologic criteria. Future studies should focus on other potential reasons including biologic, etiopathogenetic, management-related, populational, or healthcare practice-related factors that may influence the survival differences of T2 GBC in different regions.

Variant anatomy of the biliary system as a cause of pancreatic and peri-ampullary cancers

BACKGROUND

The cause of most pancreatic and periampullary cancers (PAC) is unknown. Recently, anatomic variations such as pancreatobiliary maljunction have been recognized as risk factors, similar to Barrett-related gastro-esophageal cancers.

METHODS

Pre-operative MRI from 860 pancreatic/biliary resections, including 322 PACs, were evaluated for low-union (cystic duct joining the common hepatic duct inside of the pancreas or within 5 mm of the pancreatic border) RESULTS: Low-union, seen <10% of the population, was present in 44% of PACs (73% distal bile duct/cholangiocarcinoma, 42% pancreatic head, and 34% ampullary). It was significantly lower(11%) in conditions without connection to the ductal system (thus not exposed to the ductal/biliary tract contents), namely mucinous cystic neoplasms and intrahepatic cholangiocarcinomas(p < 0.0001). Intra-pancreatic type low-union was seen in 16% of PACs versus 2% of controls(p < 0.0001).

DISCUSSION

This study establishes an association between low-union and PACs, and points to an anatomy-induced chemical/bilious carcinogenesis. This may explain why most pancreas cancers are in the head. It is possible that the same chemical milieu, caused by conditions other than low-union/insertion, may also play a role in the remaining half of PACs. This opens various treatment opportunities including milieu modifications (chemoprevention), focused screening of at-risk patients, and early detection with possible corrective actions.

Mural Intracholecystic Neoplasms Arising in Adenomyomatous Nodules of the Gallbladder: An Analysis of 19 Examples of a Clinicopathologically Distinct Entity

Intracholecystic neoplasms (ICNs) (pyloric gland adenomas and intracholecystic papillary neoplasms, collectively also called intracholecystic papillary/tubular neoplasms) form multifocal, extensive proliferations on the gallbladder mucosa and have a high propensity for invasion (>50%). In this study, 19 examples of a poorly characterized phenomenon, mural papillary mucinous lesions that arise in adenomyomatous nodules and form localized ICNs, were analyzed. Two of these were identified in 1750 consecutive cholecystectomies reviewed specifically for this purpose, placing its incidence at 0.1%. Median age was 68 years. Unlike other gallbladder lesions, these were slightly more common in men (female/male=0.8), and 55% had documented cholelithiasis. All were characterized by a compact multilocular, demarcated, cystic lesion with papillary proliferations and mucinous epithelial lining. The lesions' architecture, distribution, location, and typical size were suggestive of evolution from an underlying adenomyomatous nodule. All had gastric/endocervical-like mucinous epithelium, but 5 also had a focal intestinal-like epithelium. Cytologic atypia was graded as 1 to 3 and defined as 1A: mucinous, without cytoarchitectural atypia (n=3), 1B: mild (n=7), 2: moderate (n=2), and 3: severe atypia (n=7, 3 of which also had invasive carcinoma, 16%). Background gallbladder mucosal involvement was absent in all but 2 cases, both of which had multifocal papillary mucosal nodules. In conclusion, these cases highlight a distinct clinicopathologic entity, that is, mural ICNs arising in adenomyomatous nodules, which, by essentially sparing the "main" mucosa, not displaying "field-effect/defect" phenomenon, and only rarely (16%) showing carcinomatous transformation, are analogous to pancreatic branch duct intraductal papillary mucinous neoplasms.

Prognostic Impact of Intra-Ampullary Papillary-Tubular Neoplasm versus Flat Dysplasia as Precursor Lesions of Ampullary Adenocarcinoma

BACKGROUND

The aim of this study is to compare the prognostic impact of 2 precursor lesions of ampullary adenocarcinoma, intra-ampullary papillary-tubular neoplasm (IAPN) and flat dysplasia (FD).

METHODS

From December 1994 to December 2012, a total of 359 patients underwent curative surgery for ampullary adenocarcinoma.

RESULTS

The precursor lesions were IAPNs in 134 (37.3%) patients and FD in the other 225 (62.7%) patients. The FD group had more aggressive tumor biology with advanced T stage (p = 0.002), nodal involvement (p < 0.001), poor differentiation (p < 0.001), perineural and lymphovascular invasion (p < 0.001), and pancreatobiliary or mixed subtype (p < 0.001). Five-year overall survival rates were 71.1% in the IAPN group and 51.4% in the FD group (p = 0.002), respectively. Five-year disease-free survival rates were 69.7% in the IAPN group and 49.6% in the FD group (p < 0.001), respectively. The recurrence rate was also higher in the FD group (49.8 vs. 30.6%; p < 0.001). On multivariate analysis, higher levels of tumor markers including CEA and CA19-9, lymph node metastasis, poorly differentiated histology, and perineural invasion were negative predictive factors for survival. Higher levels of CEA and CA19-9, lymphovascular invasion, and FD were independent prognostic factors for recurrence.

CONCLUSION

FD was significantly associated with worse prognosis and a greater tendency toward advanced disease. Further studies are needed to clarify the impacts of these precursor lesions.

Gallbladder polyps: Correlation of size and clinicopathologic characteristics based on updated definitions

Background

Different perspectives exist regarding the clinicopathologic characteristics, biology and management of gallbladder polyps. Size is often used as the surrogate evidence of polyp behavior and size of ≥1cm is widely used as cholecystectomy indication. Most studies on this issue are based on the pathologic correlation of polyps clinically selected for resection, whereas, the data regarding the nature of polypoid lesions from pathology perspective -regardless of the cholecystectomy indication- is highly limited.

Methods

In this study, 4231 gallbladders -606 of which had gallbladder carcinoma- were reviewed carefully pathologically by the authors for polyps (defined as ≥2 mm). Separately, the cases that were diagnosed as “gallbladder polyps” in the surgical pathology databases were retrieved.

Results

643 polyps identified accordingly were re-evaluated histopathologically. Mean age of all patients was 55 years (range: 20–94); mean polyp size was 9 mm. Among these 643 polyps, 223 (34.6%) were neoplastic: I. Non-neoplastic polyps (n = 420; 65.4%) were smaller (mean: 4.1 mm), occurred in younger patients (mean: 52 years). This group consisted of fibromyoglandular polyps (n = 196) per the updated classification, cholesterol polyps (n = 166), polypoid pyloric gland metaplasia (n = 41) and inflammatory polyps (n = 17). II. Neoplastic polyps were larger (mean: 21 mm), detected in older patients (mean: 61 years) and consisted of intra-cholecystic neoplasms (WHO’s “adenomas” and “intracholecystic papillary neoplasms”, ≥1 cm; n = 120), their “incipient” version (<1 cm) (n = 44), polypoid invasive carcinomas (n = 26) and non-neoplastic polyps with incidental dysplastic changes (n = 33). In terms of size cut-off correlations, overall, only 27% of polyps were ≥1 cm, 90% of which were neoplastic. All (except for one) ≥2 cm were neoplastic. However, 14% of polyps <1 cm were also neoplastic. Positive predictive value of ≥1 cm cut-off -which is widely used for cholecystectomy indication-, was 94.3% and negative predictive value was 85%.

Conclusions

Approximately a third of polypoid lesions in the cholecystectomies (regardless of the indication) prove to be neoplastic. The vast majority of (90%) of polyps ≥1 cm and virtually all of those ≥2 cm are neoplastic confirming the current impression that polyps ≥1 cm ought to be removed. However, this study also illustrates that 30% of the neoplastic polyps are <1 cm and therefore small polyps should also be closely watched, especially in older patients.

Clinicopathological characteristics of intraductal papillary neoplasm of the bile duct: a Japan-Korea collaborative study

BACKGROUND

The prevalent location and incidence of intraductal papillary neoplasm of the bile duct (IPNB) and invasive carcinoma associated with them have varied markedly among studies due to differences in diagnostic criteria and tumor location.

METHODS

IPNBs were classified into two types: Type 1 IPNB, being histologically similar to intraductal papillary mucinous neoplasm of the pancreas, and Type 2 IPNB, having a more complex histological architecture with irregular papillary branching or foci of solid-tubular components. Medical data were evaluated.

RESULTS

Among 694 IPNB patients, 520 and 174 had Type 1 and Type 2, respectively. The levels of AST, ALT, ALP, T. Bil, and CEA were significantly higher in patients with Type 2 than in those with Type 1. Type 1 IPNB was more frequently located in the intrahepatic bile duct than Type 2, whereas Type 2 was more frequently located in the distal bile duct than Type 1 IPNB (P < 0.001). There were significant differences in 5-year cumulative survival rates (75.2% vs 50.9%; P < 0.0001) and 5-year cumulative disease-free survival rates (64.1% vs 35.3%; P < 0.0001) between the two groups.

CONCLUSION

Type 1 and Type 2 IPNBs differ in their clinicopathological features and prognosis. This classification may help to further understand IPNB.

Pathologic interpretation of endoscopic ultrasound-guided fine needle aspiration cytology/biopsy for pancreatic lesions

Pathologic interpretation of endoscopic ultrasound–guided fine needle aspiration (EUS-FNA) cytology/biopsy specimens is one of the most challenging tasks in cytology and surgical pathology practice, as the procedure often yields minimal amounts of diagnostic material and contains contaminants, such as blood cells and normal intestinal mucosa. EUS-FNA cytology/biopsy will nevertheless become a more popular procedure for evaluation of various pancreatic lesions because they are difficult to approach with conventional endoscopic procedures. Pathologists should understand the structural differences and limitations of EUS-FNA that make pathologic diagnosis difficult. Ancillary tests are available for differential diagnosis of EUS-FNA for various pancreatic lesions. Immunostains are the most commonly used ancillary tests, and pathologists should able to choose the necessary panel for differential diagnosis. Pathologists should review clinical history and radiologic and/or EUS findings before selecting an immunostain panel and making a pathologic diagnosis. In addition, one’s threshold of malignancy should be adjusted according to the appropriate clinical setting to avoid under-evaluation of pathologic diagnoses. Clinico-pathologic correlation is essential in pathologic evaluation of EUS-FNA for pancreatic lesions. Pathologists can reduce errors by correlating clinical and radiologic findings when evaluating EUS-FNA. Some molecular tests can be applied in differential diagnosis of pancreatic neoplastic and cystic lesions. Molecular data should be used as supportive evidence of a specific disease entity, rather than direct evidence, and should be correlated with clinico-pathologic findings to avoid errors in pathologic diagnosis.

Clinicopathologic analysis of intraductal papillary neoplasm of bile duct: Korean multicenter cohort study

BACKGROUND

IPNB is very rare disease and most previous studies on IPNB were case series with a small number due to low incidence. The aim of this study is to validate previously known clinicopathologic features of intraductal papillary neoplasm of bile duct (IPNB) based on the first largest multicenter cohort.

METHODS

Among 587 patients previously diagnosed with IPNB and similar diseases from each center in Korea, 387 were included in this study after central pathologic review. We also reviewed all preoperative image data.

RESULTS

Of 387 patients, 176 (45.5%) had invasive carcinoma and 21 (6.0%) lymph node metastasis. The 5-year overall survival was 80.9% for all patients, 88.8% for IPNB with mucosal dysplasia, and 70.5% for IPNB with invasive carcinoma. According to the "Jang & Kim's modified anatomical classification," 265 (68.5%) were intrahepatic, 103 (26.6%) extrahepatic, and 16 (4.1%) diffuse type. Multivariate analysis revealed that tumor invasiveness was a unique predictor for survival analysis. (p = 0.047 [hazard ratio = 2.116, 95% confidence interval 1.010-4.433]).

CONCLUSIONS

This is the first Korean multicenter study on IPNB through central pathologic and radiologic review process. Although IPNB showed good long-term prognosis, relatively aggressive features were also found in invasive carcinoma and extrahepatic/diffuse type.

Regional Lymph Node Metastasis of Scalp Angiosarcoma: A Detailed Clinical Observation Study of 40 Cases

BACKGROUND

The incidence of lymph node metastasis (LNM) of angiosarcomas is reported to be less than 15%, and elective neck management has not been indicated. This study evaluated the incidence and pattern of regional LNM in patients with scalp angiosarcomas using the clinical data of its full course to understand time-event sequences of scalp angiosarcomas.

METHODS

This retrospective study included all consecutive cases of pathology-confirmed angiosarcomas and analyzed 40 cases of scalp angiosarcomas. The survival plots were estimated using the Kaplan-Meier method, and the results are presented mainly in a descriptive manner.

RESULTS

The overall survival rate for the patients was 35.8% at 2 years. In contrast to previous reports, regional LNM was observed in more than half of the patients (52.5%) with scalp angiosarcoma. Meanwhile, a direct spread to distant organs occurred in only 27.5% of the patients. Regional LNM could predict clinical manifestation of systemic disease within 3 to 6 months. No differences in survival rates between patients with and without LNM were observed in this series. Occurrence of LNM seemed to be correlated with a high mitotic rate of primary tumors, but not with tumor grade or tumor dimension. The first-echelon lymph nodes from scalp angiosarcoma were peri-parotid, post-auricular, and level 2 lymph nodes.

CONCLUSIONS

For a localized scalp angiosarcoma, it seems reasonable for initial curative surgery to include prophylactic evaluation of regional lymph nodes for pathologic nodal staging, prognosis estimation, and the decision for systemic treatments.

Magnetic Resonance Imaging Findings of Biliary Adenofibroma

Biliary adenofibroma is a rare tumor with a bile duct origin characterized by a complex tubulocystic non-mucin secreting biliary epithelium with abundant fibrous stroma. The MRI features of biliary adenofibroma are not well established. The authors encountered two patients with biliary adenofibroma and reviewed the literature focusing on the MRI findings. A well-circumscribed multicystic tumor with septal enhancement and no intrahepatic bile duct communication may be the characteristic MRI findings of biliary adenofibroma.

Pancreatic acinar cell carcinomas and mixed acinar-neuroendocrine carcinomas are more clinically aggressive than grade 1 pancreatic neuroendocrine tumours

Acinar cell carcinomas (ACCs) and mixed acinar-neuroendocrine carcinomas (MAcNECs) of the pancreas are extremely rare carcinomas with a significant component with acinar differentiation. To date, the clinicopathological behaviours of these neoplasms remain unclear. In this study, we evaluated the histopathological and molecular characteristics of 20 ACCs and 13 MAcNECs and compared them to a cohort of 269 well-differentiated pancreatic neuroendocrine tumours (PanNETs). Compared to PanNETs, both ACCs and MAcNECs had an advanced pT classification (p<0.001), as well as more prevalent lymphovascular and perineural invasion (p=0.002) and lymph node and distant metastases (p<0.001). Patients with MAcNECs had worse overall (p<0.001) and recurrence-free survival (p<0.001) than those with PanNETs, but no significant difference with those with ACCs. Subgroup analyses revealed that patients with ACCs and MAcNECs had significantly worse recurrence-free survival than those with grade 1 PanNET (p<0.001), and patients with MAcNECs also had worse overall survival than those with grade 1 and 2 PanNETs (p<0.001, and p=0.001). ACCs presented more commonly with intraductal growth (p=0.014) than MAcNECs, while MAcNECs more often had lymph node metastasis (p=0.012) than ACCs. The telomere maintenance mechanism Alternative Lengthening of Telomeres (ALT) was assessed by telomere-specific FISH, and ALT was detected in 1 of 20 ACCs and in three of the 13 MAcNECs. Patients with MAcNECs and ACCs had worse survival and more aggressive behaviour than those with grade 1 PanNETs; thus, the clinicopathological behaviour of MAcNECs resembles ACCs rather than PanNETs. Combined neuroendocrine and acinar cell immunohistochemical markers are helpful for differentiating these different tumour types.

Subtype of intraductal papillary mucinous neoplasm of the pancreas is important to the development of metachronous high-risk lesions after pancreatectomy

Backgrounds/Aims

Although intraductal papillary mucinous neoplasm (IPMN) has showed a favorable prognosis compared to pancreatic ductal adenocarcinoma, its recurrence patterns have somewhat questionable in detail. After partial pancreatectomy for IPMN, the evaluation for risk of metachronous occurrence of high-risk lesions (HRL) in the residual pancreas is important to establish a postoperative surveillance modality and duration of follow-up. This study aimed to evaluate the factors that may predict the metachronous occurrence of HRL in the remnant pancreas after surgery of the IPMN.

Methods

From 2005 to 2016, clinicopathologic and surveillance data for 346 consecutive patients who underwent surgical resection for IPMN were reviewed retrospectively. Histologic subtype was classified as gastric, intestinal, pancreato-biliary, or oncocytic type.

Results

All of IPMN were classified as main duct (n=64, 18.5%), branch duct (n=171, 49.4%), and mixed type (n=111, 32.1%). Forty-eight patients (13.9%) experienced recurrence during follow-up. Among these, 9 patients (2.6%) were identified to metachronous development of HRL in the remnant pancreas. After multivariate analysis, high-grade dysplasia (HGD) or invasive carcinoma (IC) compared to low- or intermediate dysplasia was only independent risk factor for recurrence (HR 3.688, 95% CI 2.124– 12.524, p=0.009). The independent risk factors for metachronous development were HGD/IC (HR 8.414, 95% CI 4.310– 16.426, p=0.001), and intestinal/pancreato-biliary subtype compared to gastric subtype (HR 7.874, 95% CI 3.650– 27.027, p=0.010).

Conclusions

Patients with high-grade dysplasia or invasive carcinoma, and with intestinal or pancreatobiliary subtype should undergo close, long-term surveillance of the remnant pancreas after initial resection.

Acral malignant melanoma; emphasis on the primary metastasis and the usefulness of preoperative ultrasound for sentinel lymph node metastasis

This study aimed to evaluate the most common primary metastatic location of acral malignant melanoma and to evaluate the usefulness of preoperative ultrasound for sentinel lymph node metastasis. Ninety-eight Korean acral malignant melanoma patients were enrolled. Acral malignant melanoma was present in 76 lower limbs and in 22 upper limbs. The most common origin location was the sole (33.7%). The most common location of primary metastasis was loco-regional recurrence (22/34, 64.7%). The sensitivity, specificity, positive predictive value, and negative predictive value of preoperative sentinel lymph node ultrasound was 29.1%, 94.6%, 63.6%, and 80.5%, respectively. We postulate the unusefulness of preoperative ultrasound for sentinel lymph node metastasis in acral malignant melanoma.

Cancer Panel Assay for Precision Oncology Clinic: Results from a 1-Year Study

Next-generation sequencing (NGS)-based cancer panel tests are actively being applied in the clinic for precision oncology. Given the importance of NGS panel tests in the palliative clinical setting, it is critical to understand success rates, factors responsible for test failures, and the incidence of clinically meaningful genetic alterations. We performed NGS cancer panel test with tumors from the stomach (n = 234), colorectum (n = 196), and rare tumors (n = 105) from 535 recurrent or metastatic cancer patients for 1 year. Sequencing was successful in 483 (95.3%) archival tumor samples to find single nucleotide variant (SNV), copy number alteration (CNA), and fusion. NGS testing was unsuccessful in 52 (9.7%) specimens due to inadequate tissue (n = 28), low tumor volume (n = 19), and poor quality of nucleic acid (n = 5). According to the Tier system, variants were classified as Tier IA, 0.8%; IIC, 10.3%; IID, 2.0%; III, 66.7% for gastric: Tier IA, 3.6%; IIC, 11.6% for colorectal: Tier IA, 1.6%; IIC, 13.5%; IID, 0.5%; III, 70.8% for melanoma, and Tier IA, 9.1%; IIC, 1.8%; IID, 1.0%; III, 66.4% for GIST. In total, 30.8% of 483 sequenced cases harbored clinically meaningful variants. In Tier IA, KRAS and ERBB2 were the most commonly altered genes. Interestingly, we identified CD274 (PD-L1) amplification, PTPN11 (SHP2) SNV, TPM3-NTRK1 fusion, and FGFR3-TACC3 fusion as a rare (<2%) alteration having therapeutic targets. In conclusion, although small biopsy samples constitute half of cases, informative NGS results were successfully reported in >90% of archival tissue samples, and 30.8% of them harbored clinically meaningful variants.

Comprehensive molecular and clinical characterization of Asian melanoma patients treated with anti-PD-1 antibody

BACKGROUND

Clinical features of Asian melanoma patients are distinct from those of Western patients. This study was designed to determine the molecular and clinical characteristics of Asian melanoma patients treated with anti-PD-1 antibody.

METHODS

Patients with recurrent or metastatic melanoma who began anti-PD-1 antibody therapy between January 2015 and April 2018 were retrospectively reviewed. Patients who underwent next-generation sequencing were also analyzed.

RESULTS

A total of 152 patients were included. The median age was 61 years, and 53% of patients were female. A total of 56 patients (37%) received immunotherapy as second-line or greater chemotherapy. Primary sites were acral (38%), mucosal (31%), cutaneous (24%), uveal (2%), and unknown (5%). The overall response rate was 17% (95% CI, 11-22%), and disease control rate was 60% (95% CI, 52-68%). The median progression-free survival (PFS) was 4.2 months (95% CI, 1.8-6.6 months), and median overall survival (OS) was 32.9 months (95% CI, 20.0-45.7 months). However, BRAF^V600 and KIT mutational statuses were not associated with response or survival. High neutrophil-lymphocyte ratio (NLR) was associated with poor PFS (median PFS 6.9 vs. 2.4 months, p = 0.015) and OS (median OS NR vs. 10.4 months, p < 0.001). In multivariate analysis, high NLR independently predicted poor survival.

CONCLUSION

This study includes the largest set of integrated genomic data analyzing Asian patients with melanoma treated with immunotherapy. BRAF ^V600 and KIT mutational statuses were not associated with response or survival, and high NLR was a strong predictor of poor response to and survival with anti-PD-1 therapy.

Sarcomatoid carcinomas of the gallbladder: clinicopathologic characteristics

Sarcomatoid carcinomas recently came into the spotlight through genetic profiling studies and also as a distinct model of epithelial-mesenchymal transition. The literature on sarcomatoid carcinomas of gallbladder is limited. In this study, 656 gallbladder carcinomas (GBC) were reviewed. Eleven (1.7%) with a sarcomatoid component were identified and analyzed in comparison with ordinary GBC (O-GBC). Patients included 9 females and 2 males (F/M = 4.5 vs. 3.9) with a mean age-at-diagnosis of 71 (vs. 64). The median tumor size was 4.6 cm (vs. 2.5; P = 0.01). Nine patients (84%) presented with advanced stage (pT3/4) tumor (vs. 48%). An adenocarcinoma component constituting 1-75% of the tumor was present in nine, and eight had surface dysplasia/CIS; either in situ or invasive carcinoma was present in all cases. An intracholecystic papillary-tubular neoplasm was identified in one. Seven showed pleomorphic-sarcomatoid pattern, and four showed subtle/bland elongated spindle cells. Three had an angiosarcomatoid pattern. Two had heterologous elements. One showed few osteoclast-like giant cells, only adjacent to osteoid. Immunohistochemically, vimentin, was positive in six of six; P53 expression was > 60% in six of six, keratins in six of seven, and p63 in two of six. Actin, desmin, and S100 were negative. The median Ki67 index was 40%. In the follow-up, one died peri-operatively, eight died of disease within 3 to 8 months (vs. 26 months median survival for O-GBC), and two were alive at 9 and 15 months. The behavior overall was worse than ordinary adenocarcinomas in general but was not different when grade and stage were matched. In summary, sarcomatoid component is identified in < 2% of GBC. Unlike sarcomatoid carcinomas in the remainder of pancreatobiliary tract, these are seldom of the "osteoclastic" type and patients present with large/advanced stage tumors. Limited data suggests that these tumors are aggressive with rapid mortality unlike pancreatic osteoclastic ones which often have indolent behavior.

CCNE1 amplification is associated with liver metastasis in gastric carcinoma

With targeted therapies becoming the new standard of care in oncology, next generation sequencing (NGS) is emerging as a valuable method for analyzing the molecular underpinnings of individual tumors. Cyclin E1, encoded by CCNE1 causes activation of E2F mediated transcription and drives cells from G1 into S phase with cyclin-dependent kinase 2 (CDK2). CCNE1 amplification has been found in 11-12% of gastric cancers, but the clinical significance of this amplification remains controversial, and its association with liver metastasis has not been studied. This study included 226 patients diagnosed with advanced gastric adenocarcinoma. We performed multi-gene panel tests containing 143 genes using DNA and RNA obtained from primary (n = 197; 120 endoscopic biopsies and 77 resections) or metastatic cancer tissues (n = 29; 26 biopsies, 2 excisions, and 1 fin. needle aspiration). Among the 226 cases, 28 cases (12.4%) had CCNE1 amplification, almost half of which (n = 13, 46.4%) showed liver metastasis. In patients with CCNE1 amplification (n = 28), TP53 mutations (n = 23, 82.1%) and ERBB2 amplification (n = 8, 28.6%) were the most frequent concurrent genetic alterations. In contrast, 42 (21.2%) of 198 patients without CCNE1 amplification showed liver metastasis. CCNE1 amplification was significantly associated with liver metastasis (p = 0.004; odds ratio, 3.219). Our results show that CCNE1 amplification is significantly associated with liver metastasis in a TP53-mutated gastric cancer subtype. Given the frequent association of CCNE1 amplification with liver metastasis, close follow up for liver metastasis and further clinical trials targeting CDK2 inhibitors are warranted.

Atypical proliferative nodule in congenital melanocytic nevus with dural invasion: a case report

Here we report a case of a focal atypical proliferative nodule (PN) arising from a congenital melanocytic nevus (CMN). Diagnosis was challenging because it had both benign and malignant clinical features. Unusual histopathology, immunohistochemistry, and intraoperative findings of this atypical PN are discussed. A 5-year-old girl was admitted for a congenital 5× 5 cm sized scalp mass. This hemangioma-like soft mass showed biphasic characteristics such as a slow, gradual, and benign increase in size but worrisome dural invasion with cranial bone defect. We removed the scalp mass with clear resection margins. Interoperatively, we found that the cranial bone defect had already filled. Histopathologic examination showed CMN with focal atypical PN. The nodule showed sharp demarcation and cellular pleomorphism. However, in immunohistochemical study, Ki-67 proliferation index and expression levels of protein S-100 and Melan-A were very low. These were unusual findings of atypical PNs. Despite her worrisome preoperative radiologic features, she showed an indolent clinical course compatible with previously reported biologic behavior. The patient underwent follow-up inspection with magnetic resonance imaging every 6 months for up to 3 years. The nodule appeared to be stationary at the last visit.

The concept of nail matrix onychodermis (onychomatricodermis) in the nail unit: Histology and elastin immunohistochemistry

BACKGROUNDS

We previously demonstrated the presence of onychodermis below nail matrix and nail bed. Because nail matrix is a producer of nail plate, we hypothesized that onychodermis below nail matrix could be the nail counterpart of follicular dermal papilla. In this study, we sought to further characterize histologic, histochemical, and immunohistochemical features of nail matrix onychodermis.

METHODS AND RESULTS

Hematoxylin and eosin slides of 10 polydactyly nail units and 10 nail matrix biopsies from children and adults were reviewed. In polydactyly nail units, the onychodermis beneath nail matrix was characterized by onychofibroblasts showing abundant cytoplasm, and this area was slightly separated from the undersurface of the nail matrix. Nail matrix biopsy specimens also showed similar histology in the nail matrix onychodermis. Alcian blue stain demonstrated mucin deposition in onychofibroblasts within the nail matrix onychodermis. Immunohistochemically, elastin was rarely expressed in the nail matrix onychodermis while it was strongly expressed in the dermis of other areas of polydactyly nail units. Elastin was not expressed in follicular dermal papilla of terminal hair follicles of the scalp.

CONCLUSION

Our findings demonstrate the presence and localization of nail matrix onychodermis (onychomatricodermis). Our study also demonstrates similar elastin expression patterns in the onychomatricodermis and follicular dermal papilla.

Intraductal papillary neoplasm of the bile duct: Assessment of invasive carcinoma and long-term outcomes using MRI

BACKGROUND & AIMS

Imaging characteristics for discriminating the malignant potential of intraductal papillary neoplasm of the bile duct (IPNB) still remain unclear. This study aimed to define the magnetic resonance (MR) imaging findings that help to differentiate IPNB with an associated invasive carcinoma from IPNB with intraepithelial neoplasia and to investigate their significance with respect to long-term outcomes in patients with surgically resected IPNB.

METHODS

This retrospective study included 120 patients with surgically resected IPNB who underwent preoperative MR imaging with MR cholangiography before surgery from January 2008 and December 2017 in two tertiary referral centers. Clinical and MR imaging features of IPNB with intraepithelial neoplasia (n = 34) and IPNB with an associated invasive carcinoma (n = 86) were compared. Regarding significant features for discriminating IPNB with or without an associated invasive carcinoma, recurrence-free survival (RFS) rates were evaluated.

RESULTS

Significant MR imaging findings for differentiating IPNB with an associated invasive carcinoma from IPNB with intraepithelial neoplasia were intraductal visible mass, tumor size ≥2.5 cm, multiplicity of the tumor, bile duct wall thickening, and adjacent organ invasion (all p ≤0.002). The 1-, 3-, and 5-year RFS rates for surgically resected IPNB were 93.8%, 79.1%, and 70.0%, respectively. RFS rates were significantly lower in patients with each significant MR imaging finding of IPNB with an associated invasive carcinoma than in those without significant MR imaging findings (all p ≤0.039).

CONCLUSIONS

MR imaging with MR cholangiography may be helpful in differentiating IPNB with an associated invasive carcinoma from IPNB with intraepithelial neoplasia. Significant MR imaging findings of IPNB with an associated invasive carcinoma have a negative impact on RFS.

LAY SUMMARY

Significant magnetic resonance imaging findings that differentiated between an intraductal papillary neoplasm of the bile duct (IPNB) with an associated invasive carcinoma and an IPNB with intraepithelial neoplasia were intraductal visible mass, tumor size ≥2.5 cm, multiplicity of the tumor, bile duct wall thickening, and adjacent organ invasion. Significant magnetic resonance imaging findings of invasive IPNB have a negative impact on recurrence-free survival.

Can surgical treatment be justified for neuroendocrine carcinoma of the gallbladder?

Clinical features and treatment of GB neuroendocrine carcinoma (GB-NEC) are not well understood. This study aimed to analyze clinical outcomes of GB-NEC and verify the oncologic benefit of surgical treatment.From October 1994 to December 2014, the medical records of 31 patients with GB-NEC at a single center were retrospectively reviewed. There were 18 inoperable cases due to distant metastasis, including 7 of best supportive care (Tx.1) and 11 of non-operative palliative treatment (Tx.2). 4 patients received non-curative, palliative resection (Tx.3). Only 9 patients were able to undergo curative-intent resection (Tx.4).Among the 31 patients with GB-NEC, preoperative mean value of carbohydrate antigen 19-9 (CA 19-9) was 74.8 ± 156.1 U/mL and the median overall survival time was 10 months (range 7.0-12.0 months). Of these, 21 (67.7%) patients received systemic treatment. Among 9 patients who underwent curative-intent resection (Tx.4), 9 patients had poorly differentiated cancer cells and 7 patients received radical cholecystectomy. 6 patients had adjuvant treatment including concurrent chemoradiation therapy (CCRT) or chemotherapy alone. The recurrence rate was 88.9%. The median overall survival between 4 groups was as follows: 4.0 (3.0-18.0) months in Tx.1 (n = 7) versus 9.0 (3.0-21.0) months in Tx.2 (n = 11) versus 11.0 (3.0-15.0) months in Tx.3 (n = 4) versus 23.0 (8.0-34.0) months in Tx.4 (n = 9), respectively. Significant differences in median overall survival time existed between Tx.2 and Tx.4; 9 (3.0-21.0) months versus 23.0 (8.0-34.0) months (P = .017).Most GB-NECs show poor biologic behavior. Nonetheless, curative-intent resection could possibly promote longer survival than other treatment modalities for GB-NEC. Efforts to undergo curative resection through early detection and development of adjuvant treatment are needed.

Clinical significance of revised microscopic positive resection margin status in ductal adenocarcinoma of pancreatic head

Purpose

Recent studies have suggested microscopic positive resection margin should be revised according to the presence of tumor cells within 1mm of the margin surface in resected specimens of pancreatic cancer. However, the clinical meaning of this revised margin status for R1 resection margin was not fully clarified.

Methods

From July 2012 to December 2014, the medical records of 194 consecutive patients who underwent pancreaticoduodenectomy for ductal adenocarcinoma of the pancreatic head were analyzed retrospectively. They were divided into 3 groups on margin status; revised microscopic negative margin (rR0) – tumor exists more than 1 mm from surgical margin, revised microscopic positive margin (rR1) – tumor present within less than 1 mm from surgical margin, classic microscopic positive margin (cR1) – tumor is exposed to surgical margin.

Results

There were 76 rR0 (39.2%), 100 rR1 (51.5%), and 18 cR1 (9.3%). There was significant difference in disease-free survival rates between cR1 vs. rR1 (8.4 months vs. 24.0 months, P = 0.013). Margin status correlated with local recurrence rate (17.1% in rR0, 26.0% in rR1, and 44.4% in cR1, P = 0.048). There is significant difference in recurrence at tumor bed (11.8% in rR0 vs. 23.0 in rR1, P = 0.050). Of rR1, adjuvant treatment was found to be an independent risk factor for local recurrence (hazard ratio, 0.297; 95% confidence interval, 0.127–0.693, P = 0.005).

Conclusion

Revised R1 resection margin (rR1) affects recurrence at the tumor bed. Adjuvant treatment significantly reduced local recurrence of rR1. Accordingly, adjuvant chemoradiation for rR1 group should be taken into account.

Pathologic analyses of peritoneal nodules in gastric cancer patients during surgery-A single cancer center experience with diagnostic pitfalls

BACKGROUND

Gastric carcinoma (GC) is the second most common cause of cancer-related deaths worldwide. During operations, nodular lesions of the peritoneum are often sent for frozen section (FS). For pathologists, FS of the peritoneum is challenging due to sparse and discohesive tumor cells in a fibrotic background.

METHODS

To explore diagnostic accuracy and diagnostic pitfalls of FS in this setting, we retrospectively collected 252 peritoneal biopsies in cases with GC from January 2006 to May 2017 and compared corresponding permanent sections and patient prognosis. After review, 6 cases (2.4%) were discrepant: positive conversion was identified in 5 cases due to scarce tumor cells associated with severe fibrosis and inflammation; negative conversion was identified in one case due to papillary mesothelial cell proliferation masquerading as carcinoma.

RESULTS

Two hundred cases were finally confirmed as positive for tumor cells. Of these, 185 (92.5%) patients died of GC, with survival times ranging from 7 to 3574 (mean 415) days after operation. Fifty-two (20.6%) cases were negative for tumor, and pathologic findings included chronic inflammation with fibrosis (N = 25: associated with previous operation, 10; idiopathic, 15) and papillary mesothelial cell proliferation (N = 9). All 5 patients with frozen diagnosis converted to positive results died of GC during follow up. A total of 19 patients with peritoneal nodules diagnosed as benign on FS died with GC (79.0%), and their survival times ranged from 87 to 3649 (mean 833) days.

CONCLUSIONS

Peritoneal biopsies in patients with GC were mostly carcinoma, followed by chronic inflammation with fibrosis and papillary mesothelial cell proliferation. Deeper sections or intradepartmental consultations were helpful to reduce false negative diagnosis on FS.

Large-scale clinical validation of biomarkers for pancreatic cancer using a mass spectrometry-based proteomics approach

We performed an integrated analysis of proteomic and transcriptomic datasets to develop potential diagnostic markers for early pancreatic cancer. In the discovery phase, a multiple reaction monitoring assay of 90 proteins identified by either gene expression analysis or global serum proteome profiling was established and applied to 182 clinical specimens. Nine proteins (P < 0.05) were selected for the independent validation phase and quantified using stable isotope dilution-multiple reaction monitoring-mass spectrometry in 456 specimens. Of these proteins, four proteins (apolipoprotein A-IV, apolipoprotein CIII, insulin-like growth factor binding protein 2 and tissue inhibitor of metalloproteinase 1) were significantly altered in pancreatic cancer in both the discovery and validation phase (P < 0.01). Moreover, a panel including carbohydrate antigen 19-9, apolipoprotein A-IV and tissue inhibitor of metalloproteinase 1 showed better performance for distinguishing early pancreatic cancer from pancreatitis (Area under the curve = 0.934, 86% sensitivity at fixed 90% specificity) than carbohydrate antigen 19-9 alone (71% sensitivity).

Overall, we present the panel of robust biomarkers for early pancreatic cancer diagnosis through bioinformatics analysis that combined transcriptomic and proteomic data as well as rigorous validation on a large number of independent clinical samples.