Clinicopathologic characteristics of 29 invasive carcinomas arising in 178 pancreatic mucinous cystic neoplasms with ovarian-type stroma: implications for management and prognosis

Gradual telomere shortening in the tumorigenesis of pancreatic and hepatic mucinous cystic neoplasms

Mucinous cystic neoplasm (MCN) is one of the precursor lesions of pancreatic ductal adenocarcinoma and intrahepatic cholangiocarcinoma. The aim of this study is to examine the presence of short telomeres in promoting the tumorigenesis of MCN by measuring telomere lengths in distinct components of MCN, including the mucinous lining epithelium, non-mucinous lining epithelium, and ovarian-type stroma. A total of 45 patients with MCN (30 pancreatic and 15 hepatic cases) were obtained. Quantitative telomere-specific fluorescent in situ hybridization was performed to measure the telomere length of specific cell types within MCNs, including mucinous lining epithelium, non-mucinous lining epithelium, and ovarian-type stroma, as well as normal ductal epithelium and adenocarcinoma. Relative telomere lengths tended to decrease between normal ductal epithelium, ovarian-type stroma, non-mucinous lining epithelium, mucinous lining epithelium, and adenocarcinoma regardless of the involved organs. Among the analyzed cell types, relative telomere lengths were significantly different between normal ductal epithelium (3.31 ± 0.78), ovarian-type stroma (2.90 ± 0.93), non-mucinous lining epithelium (2.84 ± 0.79), mucinous lining epithelium (2.49 ± 0.93), and adenocarcinoma (1.19 ± 0.59), respectively (P < 0.001, mixed-effects model). As expected, no difference in relative telomere lengths was observed between normal ductal epithelium and ovarian-type stroma; however, significant differences were observed in pair-wise comparisons between ovarian-type stroma vs. non-mucinous lining epithelium (P = 0.001), non-mucinous lining epithelium vs. mucinous lining epithelium (P = 0.005), and mucinous lining epithelium vs. adenocarcinoma (P < 0.001). These findings suggest gradual telomere shortening occurs in the tumorigenesis of MCN, which may have important implications for the progression of this disease.

Neoplastic Progression in Macroscopic Precursor Lesions of the Pancreas

CONTEXT.—

Macroscopic precursor lesions of the pancreas represent a complex clinical management problem. Molecular characterization of pancreatic cysts has helped to confirm and refine clinical and pathologic classifications of these lesions, inform our understanding of tumorigenesis in the pancreas, and provide opportunities for preoperative diagnosis.

OBJECTIVE.—

To review the pathologic classification of macroscopic cystic lesions of the pancreas: intraductal papillary mucinous neoplasms (IPMNs), mucinous cystic neoplasms (MCNs), intraductal oncocytic papillary neoplasms (IOPNs), and intraductal tubulopapillary neoplasms (ITPNs), and to describe our current state of understanding of their molecular underpinnings, relationship to invasive carcinomas, and implications for diagnosis and prognostication.

DATA SOURCES.—

We assessed the current primary literature and current World Health Organization Classification of Digestive System Tumours.

CONCLUSIONS.—

Macroscopic cystic lesions of the pancreas are morphologically and molecularly diverse. IPMNs and MCNs share mucinous cytoplasm with papillae. MCNs are defined by ovarian-type stroma. IOPNs have granular eosinophilic cytoplasm, prominent nucleoli, and complex, arborizing papillae. ITPNs demonstrate complex, back-to-back tubules and anastomosing papillae and lack prominent intracellular mucin. IPMNs and MCNs are characterized by driver mutations in KRAS/GNAS (IPMNs) and KRAS (MCNs), with later driver events in RNF43, CDKN2A, SMAD4, and TP53. In contrast, IOPNs and ITPNs have recurrent rearrangements in PRKACA/PRKACB and MAPK-associated genes, respectively. The recurrent alterations described in cysts provide an opportunity for diagnosis using aspirated cyst fluid. Molecular characterization of IPMNs shows a striking spatial and mutational heterogeneity, challenging traditional models of neoplastic development and creating challenges to interpretation of cyst fluid sequencing results.

Precision therapy for cancer prevention by targeting carcinogenesis

Cancer represents a major global public health burden, with new cases estimated to increase from 14 million in 2012 to 24 million by 2035. Primary prevention is an effective strategy to reduce the costs associated with cancer burden. For example, measures to ban tobacco consumption have dramatically decreased lung cancer incidence and vaccination against human papillomavirus can prevent cervical cancer development. Unfortunately, the etiological factors of many cancer types are not completely clear or are difficult to actively control; therefore, the primary prevention of such cancers is not practical. In this review, we update the progress on precision therapy by targeting the whole carcinogenesis process, especially for three high-risk groups: (1) those with chronic inflammation, (2) those with inherited germline mutations, and (3) those with precancerous lesions like polyps, gastritis, actinic keratosis or dysplasia. We believe that attenuating chronic inflammation, treating precancerous lesions, and removing high-risk tissues harboring germline mutations are precision methods for cancer prevention.

Comparison with surgically resected mucinous cystic neoplasm of pancreas and branch-duct type intraductal papillary mucinous neoplasm considering clinico-radiological high-risk features: a reassessment of current guidelines

PURPOSE

To perform a comparative analysis of surgically resected mucinous cystic neoplasm (MCN) of pancreas and branch-duct type intraductal papillary mucinous neoplasms (BD-IPMN) considering clinico-radiological high-risk predictors for malignant tumors using the current management guidelines.

MATERIALS AND METHODS

224 patients who underwent surgical resection and had histopathologically confirmed MCNs (benign 73; malignant 17) or BD-IPMNs (benign 110; malignant 24) and had pre-operative CT or MRI were retrospectively reviewed. Tumors classified as either high-grade dysplasia or invasive carcinoma were considered malignant, whereas those with low-grade dysplasia were considered benign. Imaging features were analyzed by two radiologists based on selected high-risk stigmata or worrisome features proposed by prevalent guidelines except tumors with main pancreatic duct dilatation (> 5 mm) were excluded.

RESULTS

MCNs and BD-IPMNs showed significant differences in aspects like tumor size, location, the presence and size of enhancing mural nodules, the presence of wall or septal thickening, and multiplicity. Multivariate analyses revealed tumor size (OR, 1.336; 95% CI, 1.124-1.660, p = 0.002) and the presence of enhancing mural nodules (OR, 67.383; 95% CI, 4.490-1011.299, p = 0.002) as significant predictors of malignant MCNs. The optimal tumor size differentiating benign from malignant tumor was 8.95 cm, with a 70.6% sensitivity, 89% specificity, PPV of 27.6%, and NPV of 96.9%, demonstrating superior specificity than the guideline-suggested threshold of 4.0 cm. For malignant BD-IPMNs, the presence of enhancing mural nodules (OR, 15.804; 95% CI, 4.439-56.274, p < 0.001) and CA 19 - 9 elevation (OR, 19.089; 95%CI, 2.868-127.068, p = 0.002) as malignant predictors, with a size of enhancing mural nodule threshold of 5.5 mm providing the best malignancy differentiation.

CONCLUSION

While current guidelines may be appropriate for managing BD-IPMNs, our results showed a notably larger optimal threshold size for malignant MCNs than that suggested by current guidelines. This warrants reconsidering existing guideline thresholds for initial risk stratification and management of MCNs.

A narrative review on rare types of pancreatic cancer: should they be treated as pancreatic ductal adenocarcinomas?

Pancreatic cancer is one of the deadliest malignancies in humans and it is expected to play a bigger part in cancer burden in the years to come. Pancreatic ductal adenocarcinoma (PDAC) represents 85% of all primary pancreatic malignancies. Recently, much attention has been given to PDAC, with significant advances in the understanding of the mechanisms underpinning disease initiation and progression, along with noticeable improvements in overall survival in both localized and metastatic settings. However, given their rarity, rare histological subtypes of pancreatic cancer have been underappreciated and are frequently treated as PDAC, even though they might present non-overlapping molecular alterations and clinical behavior. While some of these rare histological subtypes are true variants of PDAC that should be treated likewise, others represent separate clinicopathological entities, warranting a different therapeutic approach. In this review, we highlight clinical, pathological, and molecular aspects of rare histological types of pancreatic cancer, along with the currently available data to guide treatment decisions.

Estrogen Receptor Expression in DICER1-related Lesions is Associated With the Presence of Cystic Components

DICER1 tumor predisposition syndrome results from pathogenic variants in DICER1 and is associated with a variety of benign and malignant lesions, typically involving kidney, lung, and female reproductive system. Over 70% of sarcomas in DICER1 tumor predisposition syndrome occur in females. Notably, pediatric cystic nephroma (pCN), a classic DICER1 tumor predisposition syndrome lesion, shows estrogen receptor (ER) expression in stromal cells. There are also renal, hepatic, and pancreatic lesions unassociated with DICER1 tumor predisposition syndrome that have an adult female predominance and are characterized/defined by ER-positive stromal cells. Except for pCN, the expression of ER in DICER1-associated lesions remains uninvestigated. In the present study, ER expression was assessed by immunohistochemistry in 89 cases of DICER1-related lesions and 44 lesions lacking DICER1 pathogenic variants. Expression was seen in stromal cells in pCN and pleuropulmonary blastoma (PPB) types I and Ir, whereas anaplastic sarcoma of kidney and PPB types II and III were typically negative, as were other solid tumors of non-Müllerian origin. ER expression was unrelated to the sex or age of the patient. Expression of ER showed an inverse relationship to preferentially expressed antigen in melanoma (PRAME) expression; as lesions progressed from cystic to solid (pCN/anaplastic sarcoma of kidney, and PPB types I to III), ER expression was lost and (PRAME) expression increased. Thus, in DICER1 tumor predisposition syndrome, there is no evidence that non-Müllerian tumors are hormonally driven and antiestrogen therapy is not predicted to be beneficial. Lesions not associated with DICER1 pathogenic variants also showed ER-positive stromal cells, including cystic pulmonary airway malformations, cystic renal dysplasia, and simple renal cysts in adult kidneys. ER expression in stromal cells is not a feature of DICER1 perturbation but rather is related to the presence of cystic components.

Undifferentiated carcinoma with osteoclast-like giant cells of the pancreas: An individual participant data meta-analysis

Undifferentiated carcinoma with osteoclast-like giant cells (UC-OGCs) of the pancreas is a rare neoplasm that accounts for less than 1% of all pancreatic malignancies. The aim of this study was to review the literature regarding UC-OGC, and to highlight its biological behavior, clinicopathologic characteristics, prognosis, and therapeutic options. A systematic review of the literature in PubMed/Medline and Scopus databases was performed (last search October 31st, 2023) for articles concerning pancreatic UC-OGC in the adult population. Fifty-seven studies met the inclusion criteria, involving 69 patients with a male-to-female ratio of 1.1:1 and a mean age of 62.96. Main symptoms included abdominal pain (33.3%), jaundice (14.5%), weight loss (8.7%), while fourteen patients (20.3%) were asymptomatic. Surgical resection was performed in 88.4% of cases. Survival rates at one, three, and five years were 58%, 44.7%, and 37.3% respectively. Sex, age, size (cut-off of 4 cm), location, and adjuvant treatment did not significantly affect patient survival. UC-OGC of the pancreas is a rare subtype of undifferentiated pancreatic carcinoma with a better prognosis than conventional pancreatic ductal adenocarcinoma or undifferentiated carcinoma without giant cells. The establishment of a dedicated patient registry is imperative to further delineate the optimal treatment for this uncommon clinical entity.

Dysplasia and Early Carcinoma of the Gallbladder and Bile Ducts: Terminology, Classification, and Significance

Most precursor lesions and early cancerous changes in the gallbladder and bile ducts present as clinically/grossly inapparent lesions. Low-grade dysplasia is difficult to define and clinically inconsequential by itself; however, extra sampling is required to exclude accompanying significant lesions. For high-grade dysplasia ('carcinoma in situ'), a complete sampling is necessary to rule out invasion. Tumoral intramucosal neoplasms (ie, intracholecystic and intraductal neoplasia) form radiologically/grossly visible masses, and they account for (present in the background of) about 5% to 10% of invasive cancers of the region. These reveal a spectrum of papilla/tubule formation, cell lineages, and dysplastic transformation. Some subtypes such as intracholecystic tubular non-mucinous neoplasm of the gallbladder (almost never invasive) and intraductal oncocytic or intraductal tubulopapillary neoplasms of the bile ducts (may have a protracted clinical course even when invasive) are to be noted separately. Other types of intracholecystic/intraductal neoplasia have a high frequency of invasive carcinoma and progressive behavior, which often culminates in mortality.

Early Cancerous Lesions of the Pancreas and Ampulla: Current Concepts and Challenges

Owing to the increased use of advanced imaging techniques, mass-forming (cystic/intraductal) preinvasive neoplasms are being detected much more frequently and they have rapidly become one of the main focuses of interests in medical field. These neoplasms have very distinctive clinical and radiographic findings, exhibit a spectrum of dysplastic transformation, from low-grade dysplasia to high-grade dysplasia, and may be associated with an invasive carcinoma. Accounting for about 5% to 10% of pancreatic ductal adenocarcinomas, they provide a curable target subset in an otherwise biologically dismal pancreas cancer category.

Inadequacy of the eighth edition of the American Joint Committee on Cancer pancreatic cancer staging system for invasive carcinoma associated with premalignant lesions in the pancreas: an analysis using the National Cancer Database

BACKGROUND

Invasive carcinomas arising from premalignant lesions are currently staged by the same criteria as conventional pancreatic ductal adenocarcinoma.

METHODS

Clinicopathologic information and survival data were extracted through a thorough search of histology codes from National Cancer Database (2006-2016). A total of 723 patients with invasive intraductal papillary mucinous neoplasm and mucinous cystic neoplasm were analyzed.

RESULTS

The median age was 67 years, and 351 patients (48.5%) were male. There were 212 (29.3%), 232 (32.1%), 272 (37.6%), and 7 (1.0%) patients with T1, T2, T3, and T4 classification. Extrapancreatic extension (EPE) was present in 284 (39.3%). Age (HR = 1.504, 95% CI 1.196-1.891), R1 or R2 resection (HR = 1.585, 95% CI 1.175-2.140), and EPE (HR = 1.598, 95% CI 1.209-2.113) were independent prognostic factors for overall survival. Size criteria did not significantly affect survival. The median survival was 115.9 months for patients without EPE, compared to 34.2 months for those with EPE. EPE discriminated survival better than tumor size.

DISCUSSION

The T classification of the eighth edition AJCC staging system is not adequate for invasive carcinomas associated with premalignant lesions of the pancreas. They merit a separate, dedicated staging system that uses appropriate prognostic factors.

Pathologic Features of Primary Pancreatic Malignancies

This chapter explores the pathologic features of benign and malignant lesions of the pancreas. As pathologic classifications evolve particularly for cystic lesions and neuroendocrine tumors, it is important for physicians who treat patients with gastrointestinal malignance to fully evaluate these pathologic classifications.

Optimal carcinoembryonic antigen (CEA) cutoff values in the diagnosis of neoplastic mucinous pancreatic cysts differ among assays

AIM

Pancreatic cyst fluid carcinoembryonic antigen (CEA) is a pivotal test in the diagnosis and management of neoplastic mucinous cysts (NMC) of the pancreas. Cyst fluid CEA levels of 192 ng/mL have been widely used to identify NMC. However, CEA values are unique to and significantly differ between individual assays with various optimal cutoffs reported in the literature for NMC. Here, we investigate the optimal CEA cut-off value of pancreatic cysts from two different assays to identify differences in thresholds.

METHODS

Pancreatic cyst fluid CEA levels, CEA assay platform (Beckman Dxl (BD) or Siemens Centaur XP (SC)), and clinical/pathological information were retrospectively collected. Cases were categorised into either NMC or non-NMC. Optimal CEA cut-off values were calculated via a receiver operator characteristic curve. Cut-off values were then identified separately by assay platform.

RESULTS

In total, 149 pancreatic cystic lesions with concurrent CEA values (SC: n=47; BD: n=102) were included. Histological correlation was available for 26 (17%) samples. The optimal CEA cut-off value for all samples at the study institution was 45.9 ng/mL (area under the curve (AUC)=86, Sn=85.7%, Sp=73.8%). When analysed separately by CEA assay, the cut-off values were 45.9 ng/mL (AUC=84.27, Sn=89.7%, Sp=71.4%) for BD and 24.4 ng/mL (AUC=77, Sn=81.8%, Sp=75%) for SC (p=0.48).

CONCLUSIONS

This study showed an optimal pancreas cyst CEA cut-off threshold of 45.9 ng/mL, which is lower than commonly cited literature with different cutoffs on the two separate platforms (BD: 45.9 ng/mL, SC: 24.4 ng/mL).

Comprehensive characterisation of acinar cystic transformation of the pancreas: a systematic review

AIMS

Acinar cystic transformation (ACT) of the pancreas is a rare pancreatic cystic lesion. Owing to its rarity, comprehensive histomolecular characterisation of this entity is still lacking. We aim to perform a systematic review on this controversial entity.

METHODS

We searched PubMed, SCOPUS and Embase through May 2023 to identify all studies on ACTs. Clinicopathological, immunohistochemical (IHC) and molecular data have been extracted and analysed.

RESULTS

Overall, there were 121 cases of ACTs in the literature. ACT had a female predominance (65.3% of patients), and a mean size of 4.8 cm. ACT was more often unifocal (71.9%) and multiloculate (61.2%). Histologically, the cysts were lined by an acinar epithelium, sometimes harbouring ductal-like areas (18.2%). In five cases (4.1%), an intralesional pancreatic intraepithelial neoplasia (PanIN) was reported. Preoperative diagnosis is challenging. After surgical resection, all patients were alive and disease free during follow-up except one patient who developed a second ACT after resection. By IHC, all lesions were positive for acinar markers; cytokeratin 7 and 8/18/19 were usually positive, and Ki-67 was invariably ≤3%. At the molecular level, three cases demonstrated genetic alterations: one showed multiple chromosomal gains, and other two harboured somatic mutations of KRAS and SMO genes (one mutation per case).

CONCLUSIONS

Globally considered, our findings demonstrated that ACT is a benign entity, without the need of surgical resection with the exception of symptomatic lesions. The rare occurrence of intracystic PanINs and driver mutations suggest considering follow-up if a preoperative diagnosis of ACT can be made.

Mucinous cystic liver neoplasm with invasive component and sarcomatous differentiation

BACKGROUND

Hepatobiliary mucinous cystic neoplasms (MCN) harbor an invasive carcinoma in 16% of the cases, mainly tubular type, but occasionally sarcomatoid or undifferentiated, these entities being frankly rare.

METHODS

We present the case of a liver MCN with an invasive component and sarcomatous degeneration.

RESULTS

The patient was treated surgically with subsequent adjuvant chemotherapy (capecitabine), presenting tumor progression after three months with peritoneal carcinomatosis and liver recurrence. The patient died due to liver failure 4 months after surgery.

CONCLUSION

MCN with an invasive component and sarcomatous degeneration are very rare, present advanced stages, show aggressive behavior, and have a poor prognosis.

Malignancy risk factors and prognostic variables of pancreatic mucinous cystic neoplasms in Chinese patients

BACKGROUND

Pancreatic mucinous cystic neoplasms (MCNs) represent one of the precursor lesions of pancreatic ductal adenocarcinoma, and their detection has been facilitated by advances in preoperative imaging. Due primarily to the rarity of MCNs, however, there is limited knowledge regarding the prognostic variables and high-risk factors for malignant transformation. A more comprehensive and nuanced approach is necessary to fill this gap and provide a basis for improved treatment decisions and patient outcomes.

AIM

To investigate the high-risk factors associated with malignant MCNs and to explore the prognostic factors of MCN with associated invasive carcinoma (MCN-AIC).

METHODS

All cases of resected MCNs from a single high-volume institution between January 2012 and January 2022 were retrospectively reviewed. Only cases with ovarian-type stroma verified by progesterone receptor staining were included. Preoperative features, histological findings and postoperative course were documented. Multivariate logistic regression was employed to investigate variables related to malignancy. Survival analysis was performed using the Kaplan-Meier curve, and the prognostic factors were assessed to evaluate the postoperative course of patients with MCN-AIC.

RESULTS

Among the 48 patients, 36 had benign MCNs, and 12 had malignant MCNs (1 high-grade atypical hyperplasia and 11 MCN-AIC). Age, tumour size, presence of solid components or mural nodules and pancreatic duct dilatation were identified as independent risk factors associated with malignancy. The follow-up period ranged from 12 mo to 120 mo, with a median overall survival of 58.2 mo. Only three patients with MCN-AIC died, and the 5-year survival rate was 70.1%. All 11 cases of MCN-AIC were stage I, and extracapsular invasion was identified as a prognostic factor for poorer outcomes.

CONCLUSION

The risk factors independently associated with malignant transformation of MCNs included age, tumour size, presence of solid components or mural nodules, and pancreatic duct dilatation. Our study also revealed that encapsulated invasion was a favourable prognostic factor in MCN-AIC patients.

CYSTIC PANCREATIC LESIONS: IMAGING VERSUS ANATOMOPATHOLOGICAL FINDINGS-HOW TO IMPROVE DIAGNOSTIC ACCURACY?

BACKGROUND

Pancreatic cystic lesions are a group of pancreatic neoplasms with different behavior and risk of malignancy. Imaging diagnosis and differentiation of these lesions remain a challenge.

AIMS

The aim of this study was to evaluate the agreement between computed tomography and/or magnetic resonance imaging and post-operative pathologic diagnoses of Pancreatic cystic lesions in a University Hospital of São Paulo State.

METHODS

A total of 39 patients with surgically diagnosed Pancreatic cystic lesions were enrolled, as a study cohort from 2009 to 2019. Preoperative radiological and final pathological diagnosis was correlated to measure computed tomography and/or magnetic resonance imaging diagnostic. Pancreatic adenocarcinoma, choledochal pancreatic cyst, mucinous cystadenoma, serous cystadenoma, intraductal papillary mucinous neoplasms, and pancreatic pseudocyst were classified as neoplastic cysts.

RESULTS

It was noted that 27 patients (69.23%) had preoperative computed tomography and magnetic resonance imaging, 11 patients (28.20%) had preoperative computed tomography only, and 1 patient had preoperative magnetic resonance imaging only. The values for diagnoses made only with computed tomography (p=0.47) and from the combination of computed tomography+magnetic resonance imaging (p=0.50) did also point to moderate agreement with the anatomopathological findings. The values pointed to a fair agreement for the diagnosis of mucinous cystadenoma (p=0.3), moderate agreement for intraductal papillary mucinous neoplasms (p= 0.41), good agreement for serous cystadenoma (p=0.79), and excellent agreement for choledochal pancreatic cyst (p=1), pancreatic pseudocyst (p=0.84), and Frantz tumor (p=1) (p<0.05).

CONCLUSIONS

The findings of computed tomography and/or magnetic resonance imaging have an equivalent diagnostic agreement with an anatomopathological diagnosis for differentiating benign from malignant Pancreatic cystic lesions and in suggesting a specific diagnosis. There is no statistical difference between the use of computed tomography alone and computed tomography+magnetic resonance imaging in the improvement of diagnostic accuracy.

Huge mucinous cystic neoplasms with adhesion to the left colon: A case report and literature review

Mucinous cystic neoplasms (MCN) are rare premalignant neoplasms of the pancreas typically found as single lesions in the pancreatic body and tail of women in the fifth and sixth decade of life, constituting 2-5% of pancreatic neoplasms. We present a 50-year-old female patient with a large tail mass of the pancreatic body (size of 15 cm × 12 cm) with elevated tumor indicators. Computed tomography and magnetic resonance imaging revealed a large cystic lesion with septa and wall nodules. During the operation, the tumor capsule wall adhered to the left half colon and mesentery and could not be detached. Splenectomy and left hemicolectomy were performed. The postoperative pathological examination of the specimens confirmed a premalignant pancreatic mucous cystic tumor with moderate heterocytosis. The preoperative diagnosis of pancreatic MCN and MCN with invasive carcinoma is discussed, considering the characteristics of this case. Age, tumor size, texture, tumor marker elevation, and cystic wall condition are important characteristics of malignant MCN. Nevertheless, it is still very difficult to determine accurately whether an MCN is malignant or not before an actual pathological examination of the resected specimen.

Pancreatic Cystic Lesions: A Focused Review on Cyst Clinicopathological Features and Advanced Diagnostics

Macroscopic, endomicroscopic, and histologic findings and correlation are an integral part of the diagnostic evaluation of pancreatic cystic lesions (PCLs), as complementing morphologic features seen by different specialties are combined to contribute to a final diagnosis. However, malignancy risk stratification of PCLs with worrisome features can still be challenging even after endoscopic ultrasound guided-fine needle aspiration (EUS-FNA) with cytological evaluation. This review aims to summarize cyst clinicopathological features from the pathologists' perspective, coupled with knowledge from advanced diagnostics-confocal laser endomicroscopy and cyst fluid molecular analysis, to demonstrate the state-of-art risk stratification of PCLs. This review includes illustrative photos of surgical specimens, endomicroscopic and histologic images, and a summary of cyst fluid molecular markers.

Integrating Molecular Analysis into the Pathologic Evaluation of Pancreatic Cysts

The development of cross-sectional imaging techniques has enhanced the detection of pancreatic cystic lesions (PCLs). PCLs are found in approximately 2% of the general population, often as incidentally detected lesions on computed tomography or MRI during the evaluation of other medical conditions. Broadly, PCLs are classified as mucinous or nonmucinous. Mucinous PCLs include mucinous cystic neoplasms and intraductal papillary mucinous neoplasms. Nonmucinous PCLs include pseudocysts, serous cystadenomas, solid pseudopapillary neoplasms, and cystic pancreatic neuroendocrine tumors, as well as cystic acinar cell carcinoma, cystic degeneration of pancreatic ductal adenocarcinoma, lymphoepithelial cyst, and others.

Hepatic Cysts: Reappraisal of the Classification, Terminology, Differential Diagnosis, and Clinicopathologic Characteristics in 258 Cases

The literature on liver cysts is highly conflicting, mostly owing to definitional variations. Two hundred and fifty-eight ≥1 cm cysts evaluated pathologically using updated criteria were classifiable as: I. Ductal plate malformation related (63%); that is, cystic bile duct hamartoma or not otherwise specified-type benign biliary cyst (35 with polycystic liver disease). These were female predominant (F/M=2.4), large (10 cm), often multifocal with degenerative/inflammatory changes and frequently misclassified as "hepatobiliary cystadenoma." II. Neoplastic (13%); 27 (10.5%) had ovarian-type stroma (OTS) and qualified as mucinous cystic neoplasm (MCN) per World Health Organization (WHO). These were female, solitary, mean age 52, mean size 11 cm, and 2 were associated with carcinoma (1 in situ and 1 microinvasive). There were 3 intraductal papillary neoplasms, 1 intraductal oncocytic papillary neoplasm, 1 cystic cholangiocarcinoma, and 2 cystic metastasis. III. Infectious/inflammatory (12%). These included 23 hydatid cysts (including 2 Echinococcus alveolaris both misdiagnosed preoperatively as cancer), nonspecific inflammatory cysts (abscesses, inflammatory cysts: 3.4%). IV. Congenital (7%). Mostly small (<3 cm); choledochal cyst (5%), foregut cyst (2%). V. Miscellaneous (4%). In conclusion, hepatic cysts occur predominantly in women (3/1), are mostly (90%) non-neoplastic, and seldom (<2%) malignant. Cystic bile duct hamartomas and their relative not otherwise specified-type benign biliary cysts are frequently multifocal and often misdiagnosed as "cystadenoma/carcinoma." Defined by OTS, MCNs (the true "hepatobiliary cystadenoma/carcinoma") are solitary, constitute only 10.5% of hepatic cysts, and have a significantly different profile than the impression in the literature in that essentially all are perimenopausal females, and rarely associated with carcinoma (7%). Since MCNs can only be diagnosed by demonstration of OTS through complete microscopic examination, it is advisable to avoid the term "cystadenoma/cystadenocarcinoma" solely based on radiologic examination, and the following simplified terminology would be preferable in preoperative evaluation to avoid conflicts with the final pathologic diagnosis: (1) noncomplex (favor benign), (2) complex (in 3 subsets, as favor benign, cannot rule out malignancy, or favor malignancy), (3) malignant features.

Single-cell RNA-seq reveals the genesis and heterogeneity of tumor microenvironment in pancreatic undifferentiated carcinoma with osteoclast-like giant-cells

BACKGROUND

Undifferentiated carcinoma with osteoclast-like giant cells (OGCs) of pancreas (UCOGCP) is a rare subtype of pancreatic ductal adenocarcinoma (PDAC), which had poorly described histopathological and clinical features.

METHODS

In this study, single-cell RNA sequencing (scRNA-seq) was used to profile the distinct tumor microenvironment of UCOGCP using samples obtained from one UCOGCP patient and three PDAC patients. Bioinformatic analysis was carried out and immunohistochemical (IHC) staining was used to support the findings of bioinformatic analysis. After quality control of the raw data, a total of 18,376 cells were obtained from these four samples for subsequent analysis. These cells were divided into ten main cell types following the Seurat analysis pipeline. Among them, the UCOGCP sample displayed distinct distribution patterns from the rest samples in the epithelial cell, myeloid cell, fibroblast, and endothelial cell clusters. Further analysis supported that the OGCs were generated from stem-cell-like mesenchymal epithelial cells (SMECs).

RESULTS

Functional analysis showed that the OGCs cluster was enriched in antigen presentation, immune response, and stem cell differentiation. Gene markers such as LOX, SPERINE1, CD44, and TGFBI were highly expressed in this SMECs cluster which signified poor prognosis. Interestingly, in myeloid cell, fibroblasts, and endothelial cell clusters, UCOGCP contained higher percentage of these cells and unique subclusters, compared with the rest of PDAC samples.

CONCLUSIONS

Analysis of cell communication depicted that CD74 plays important roles in the formation of the microenvironment of UCOGCP. Our findings illustrated the genesis and function of OGCs, and the tumor microenvironment (TME) of UCOGCP, providing insights for prognosis and treatment strategy for this rare type of pancreatic cancer.

State-of-the-Art Update of Pancreatic Cysts

Andrew Canakis.

A Review of Mucinous Cystic and Intraductal Neoplasms of the Pancreatobiliary Tract

CONTEXT.—

Although most pancreatic and bile duct neoplasms are solid, mucinous cystic neoplasms and intraductal neoplasms have been increasingly recognized even when clinically silent, thanks to the increased use of sensitive imaging techniques. Cystic and intraductal neoplasms of the pancreas are often resectable and curable and constitute about 5% of all pancreatic neoplasms. Owing to their preinvasive nature and different biology, recognition of these entities remains a major priority. Mucinous cystic neoplasms are histologically and clinically distinct from other cystic pancreatic neoplasms. Pancreatic intraductal neoplasms encompass 3 major entities: intraductal papillary mucinous neoplasm, intraductal oncocytic papillary neoplasm, and intraductal tubulopapillary neoplasm. Intraductal papillary neoplasms of bile ducts are also preinvasive mass-forming neoplasms with both similarities and differences with their pancreatic counterparts. All of these pancreatobiliary neoplasms have diverse and distinctive clinicopathologic, genetic, and prognostic variations.

OBJECTIVE.—

To review the clinical, pathologic, and molecular features of mucinous cystic and intraductal neoplasms of the pancreatobiliary tract.

DATA SOURCES.—

Literature review, diagnostic manuals, and guidelines.

CONCLUSIONS.—

This review will briefly describe well-known clinical and pathologic features and will focus on selected recently described aspects of morphology, grading, classification, and genomic alterations of cystic and intraductal neoplasms of the pancreatobiliary tract.

RNF43 as a predictor of malignant transformation of pancreatic mucinous cystic neoplasm

Mucinous cystic neoplasm (MCN) of the pancreas rarely progresses to invasive carcinoma, but few studies have analyzed genomic alterations involved in its malignant transformation. The relationships of ring finger protein 43 (RNF43) mutations with cytological atypia, RNF43 protein expression, and Wnt signaling proteins in MCN remain unclear. This study included 106 MCN cases, classified into 89 low-grade dysplasia (LG), 9 high-grade dysplasia (HG), and 8 invasive carcinoma (INV). We analyzed HG/INV and LG lesions of 9 HG/INV cases and LG lesions of 9 LG cases using targeted sequencing and confirmed the protein expression of RNF43 and β-catenin. The frequency of RNF43 mutations was significantly higher in HG/INV cases than in LG cases. Furthermore, HG/INV lesions (56%) and LG lesions (33%) of HG/INV cases possessed RNF43 mutation, whereas no such mutation was detected in any LG cases. The expression of RNF43 was reduced in 71% of HG/INV cases and significantly correlated with histological grade and aberrant expression of β-catenin. In 3 of 5 RNF43-mutated cases, the expression of RNF43 was reduced, but there was no significant correlation between RNF43 mutation and protein expression. MCNs frequently harbored KRAS mutations, at rates of 100% in HG/INV lesions and 50% in LG lesions of HG/INV and LG cases. There was no significant difference in mutation frequency in LG lesions between HG/INV and LG cases. These results suggest that RNF43 mutations may be involved in and predictive of malignant transformation from an early stage of MCN.

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.

Diagnostic Concordance and Preoperative Risk Factors for Malignancy in Pancreatic Mucinous Cystic Neoplasms

Background/Aims

Methods

Results

Conclusions

Cephalic undifferentiated carcinoma with osteoclast-like giant cells arising from the main pancreatic duct: case report and literature review

Undifferentiated carcinoma with osteoclast-like giant cell (UCOGC) is a ductal carcinoma variant with a recently reported more protracted survival and pathognomonic histology comprising two cell populations: the mononuclear tumoral cells and nontumoral multinucleated giant cells. It usually presents as a large heterogenic tumor with mixed solid-cystic components. The tumor develops from the ductal epithelium but the sequence of epithelial changes is often not identified due to the rapid tumoral growth and associated necrotic changes. We report a case of a 76-year-old patient diagnosed with cephalic UCOGC originating in the epithelium of the main pancreatic duct with endoluminal growth and foci of other ductal neoplasms (high-grade pancreatic intraepithelial neoplasia (PanIN) and conventional ductal carcinoma). The particularity of our case consists in the identification of the columnar epithelium conversion, through high-grade PanIN, into UCOGC specific malignant features, in a large size tumor - aspect usually reported in small tumors. Alongside our case we also present a brief literature review of cephalic UCOGC case reports and case series.

Pathologic T1 and T2 encapsulated invasive carcinomas arising from mucinous cystic neoplasms of the pancreas have favorable prognosis and might be treated conservatively

Carcinoma arising from a mucinous cystic neoplasm (MCN) of the pancreas is termed MCN with associated invasive carcinoma (MCN-AIC) in the fifth WHO classification of digestive tumors (2019). The prognosis of this malignancy varies depending on the relationship of the invasive carcinoma to the cyst capsule, but limited data are available. This study identified 165 surgically resected MCNs including 15 MCN-AICs from a single center between 2008 and 2018 and analyzed their clinicopathologic features. The results confirmed that non-invasive MCNs were completely cured by surgery. All MCN-AICs showing an encapsulated invasion pattern (defined as invasive carcinoma limited to the ovarian-type stroma, cystic septa, and capsule) had an excellent prognosis with a 5-year survival rate of 100%, even when the size of the invasive component was up to stage T2. By contrast, MCN-AICs with extracapsular involvement had unfavorable clinical outcomes. Our study demonstrates that the pattern of invasion of MCN-AIC can predict patient prognosis. Pathologic stage T1 and T2 encapsulated MCN-AICs may be completely cured with surgical resection alone or when combined with postoperative chemotherapy.

Advances in the epidemiology of pancreatic cancer: Trends, risk factors, screening, and prognosis

Pancreatic cancer is a malignancy with poor prognosis and high mortality. The recent increase in pancreatic cancer incidence and mortality has resulted in an increased number of studies on its epidemiology. This comprehensive and systematic literature review summarizes the advances in the epidemiology of pancreatic cancer, including its epidemiological trends, risk factors, risk prediction models, screening modalities, and prognosis. The risk factors for pancreatic cancers can be categorized as those related to individual characteristics, lifestyle and environment, and disease status. Several prediction models for pancreatic cancer have been developed in populations with new-onset diabetes or a family history of pancreatic cancer; however, these models require further validation. Despite recent progress in pancreatic cancer screening, the quantity and quality of related studies are also unsatisfactory, especially with respect to the identification of high-risk populations and development of effective screening modality. Apart from the populations with familial genetic risk and those at a high risk of sporadic pancreatic cancer, risk factors such as new-onset diabetes may be a new direction for timely intervention. We hope this work will provide new ideas for further prevention and treatment of pancreatic cancer.

Actual malignancy risk of either operated or non-operated presumed mucinous cystic neoplasms of the pancreas under surveillance

BACKGROUND

Despite the low malignant potential of pancreatic mucinous cystic neoplasms (MCNs), surgery is still performed. The aim of this pragmatic study was to assess the outcome of surgery and surveillance for patients presenting with a presumed MCN at the first evaluation.

METHODS

Data for patients with a presumed MCN observed from 2000 to 2016 at the Verona Pancreas Institute and San Raffaele Hospital were extracted from prospective databases. The endpoints were risk of malignancy at pathology and rate of misdiagnosis for the surgical series, expressed as an odds ratio (OR) with 95 per cent confidence interval, and disease-specific survival (DSS) for the surveillance cohort investigated by the Kaplan-Meier method.

RESULTS

A total of 424 patients were identified. In the surgical series (229 patients), the rate of misdiagnosis was 19.2 per cent. The rate of malignant MCNs was 10.9 per cent (25 patients). The overall rate of malignancy, including misdiagnoses, was 11.3 per cent (26 patients). Predictors of malignancy were mural nodules (OR 27.75, 95 per cent c.i. 4.44-173.61; P < 0.001), size at least 50 mm (OR 13.39, 2.01 to 89.47; P = 0.007), and carbohydrate antigen 19.9 level (OR 3.98, 1.19 to 13.30; P = 0.025). In the absence of mural nodules and enhancing walls, none of the resected presumed MCNs smaller than 50 mm were malignant. Only patients with high-risk stigmata undergoing surgery experienced a significantly reduced 5-year DSS compared with all other patients (88 versus 100 per cent; P = 0.031).

CONCLUSION

Presumed MCNs with mural nodules, enhancing walls or cysts of 50 mm or larger should be considered for upfront surgical resection owing to the high risk of malignancy. In the absence of these features, the incidence of malignancy is negligible, favouring surveillance in selected patients given the low risk of malignancy and the high rate of misdiagnosis.

GRAPHICAL ABSTRACT

Pancreatic mucinous cystic neoplasms (MCNs) are well known preneoplastic lesions. Despite the low rate of cancer, lesions without radiological features of malignancy are resected systematically. In the absence of mural nodules, enhancing walls or cyst size 50 mm or more, the incidence of malignancy is negligible. Given the high risk of misdiagnosis, in the absence of such radiological features, surveillance of presumed MCNs seems safer.

Educational Case: Pancreatic Cystic Disease: A Multimodal Diagnostic Approach to Determine Clinical Management

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040 . 1

A mucinous cystic neoplasm of the pancreas containing an undifferentiated carcinoma component and harboring the NRAS driver mutation

A woman in her 20s visited our hospital with a chief complaint of abdominal distension and back pain. She was diagnosed with a cystic tumor (diameter 16 cm) in the tail of the pancreas and underwent a combined distal pancreatectomy, splenectomy, and left adrenalectomy. Histopathologically, the tumor presented as a mucinous cystic neoplasm with an undifferentiated carcinoma component of the pancreas. In addition, the cells demonstrated a partial rhabdoid-like morphology. These findings were considered relatively typical for a mucinous cystic neoplasm in the tail of the pancreas in a young woman. However, NRAS mutation, which is rare in pancreatic tumors, was detected.

Undifferentiated Pancreatic Carcinoma With Osteoclast-Like Giant Cells: What Do We Know So Far?

Undifferentiated carcinoma of the pancreas is an aggressive but rare tumor for which several other terms have been used to describe its histological appearance. In addition, as osteoclast-like giant cells may accompany undifferentiated carcinoma of the pancreas, the WHO Classification distinguishes undifferentiated carcinoma with osteoclast-like giant cells (UC-OGC) from plain undifferentiated carcinoma since there are a few histopathological and clinical differences. UC-OGC was initially thought to be associated with worse prognosis compared to invasive ductal pancreatic adenocarcinoma, since it is often unresectable at diagnosis and tends to recur rapidly even if completely resected. When true UC-OGGs are carefully dissected out from other anaplastic carcinomas, it becomes, however, clear that UC-OGCs do have more indolent behavior, especially the pure UC-OGCs. This mini-review summarizes the current knowledge on UC-OGC.

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.

Mucinous cystic neoplasms of the pancreas associated with pregnancy: Two case reports

RATIONALE

Although rare, pancreatic neoplasms can occur during pregnancy, both in benign and malignant forms. Mucinous cystic neoplasms (MCNs) of the pancreas, a type of these neoplasms, are precursor lesions to invasive pancreatic cancer. The presence of the ovarian-type stroma is a defining feature.

PATIENT CONCERNS

The first case was a 38-year-old woman in her 18th week of pregnancy with abdominal pain that worsens a few weeks later. The second case was a 30-year-old woman in her 17th week of pregnancy with abdominal pain in the left hypochondrium.

DIAGNOSIS

The patients were under clinical examination and laboratory test including carbohydrate antigen 19-9 (CA 19-9) and carcinoembryonic antigen (CEA). Both patients had magnetic resonance imaging (MRI). The diagnosis of a MCNs of the pancreas was done preoperatively in the 2 cases.

INTERVENTIONS

Both patients underwent distal pancreatectomy during pregnancy. One of them was an emergency laparotomy because of a ruptured MCN.

OUTCOMES

Both patients were completely recovered from distal pancreatectomy and continued to full term, delivering a healthy baby by Caesarean section. After 6 years of follow-up, the first patient underwent a total gastrectomy, because of a gastric cancer with carcinomatosis. Currently the 2 patients are still alive after 8 years and 5 years of follow-up, respectively.

LESSONS

Surgical resection of MCNs during pregnancy should be considered during the second trimester given common distal pancreas location, rapid growth, risk of spontaneous rupture, and malignant potential.

Negative prognostic impact of PD-L1 expression in tumor cells of undifferentiated (anaplastic) carcinoma with osteoclast-like giant cells of the pancreas: study of 13 cases comparing ductal pancreatic carcinoma and review of the literature

Pancreatic carcinoma remains one of the leading cancer-related causes of death worldwide and is generally characterized by a dismal prognosis and limited potential for oncologic treatment. A rare subvariant of pancreatic cancer, undifferentiated carcinoma with osteoclast-like giant cells (UCOGC), has an unpredictable prognosis according to many previous studies, with unexpectedly long survival in individual cases. In this study, we collected, retrospectively, 13 cases of well-documented UCOGCs and performed immunohistochemistry focused on the expression of the programmed death-ligand 1 (PD-L1) and several other potential therapeutic and predictive markers (PanTRK, p53, MSH2, PMS2, and the number of tumor-infiltrating lymphocytes), to explore their correlation with the follow-up of the patients. As a control group, we examined 24 cases of conventional pancreatic ductal adenocarcinoma (PDAC). In our results, PanTRK was negative in all 24 cases. P53 did not show any significant differences between UCOGCs and PDACs, and the entire cohort was MSH2, MLH1, PMS2, and MSH6 positive. Significant differences were present in the analysis of PD-L1: UCOGCs were found to express PD-L1 significantly more frequently and have a higher number of tumor-infiltrating lymphocytes than PDAC. The expression of PD-L1 was related to significantly shorter survival in patients with UCOGC and in the entire cohort. Patients with PD-L1 negative UCOGCs displayed surprisingly long survival in comparison to PD-L1 positive UCOGCs and PDACs (both PD-L1+ and PD-L1-). We compared our results with previously published data, and, after statistical analysis, we were able to identify PD-L1 as an effective prognostic marker of UCOGC and suggest a strong need for a clinical trial of immune checkpoint immunotherapy in patients with advanced PD-L1 positive UCOGC.

Management of Incidental Pancreatic Cystic Lesions: Integrating Novel Diagnostic and Prognostic Factors With Current Clinical Guidelines

Owing to increased detection rates, the diagnosis and management of incidental pancreatic cysts has become a common predicament. Up to 13% of patients undergoing cross-sectional imaging studies for other indications are found to have pancreatic cystic lesions. Although most cystic lesions are benign, the malignant potential of several types of pancreatic cysts makes accurate classification vital to directing therapy. To this end, advances in the last decade led to better characterization of pancreatic cyst morphology and hence enhanced the ability to predict underlying histopathology, and biological behavior. Although accurate classification remains a challenge, the utilization of complementary diagnostic tools is the optimal approach to dictate management. The following review includes a description of pancreatic cysts, a critical review of current and emerging diagnostic techniques and a review of recent guidelines in the management of incidental pancreatic cysts.

Mucinous Cystadenocarcinoma of the Pancreas with Cyst Infection in a Male Patient

Follow-up computed tomography revealed a 40-mm pancreatic tail cyst in a 59-year-old man with type 1 diabetes mellitus. An intraductal papillary mucinous neoplasm was suspected; mucinous cystic neoplasm (MCN) was not considered because the patient was a man. During follow-up, cyst infection occurred but was improved by conservative treatment. At the 24-month follow up examination, cyst nodules had developed, corresponding to an increase in the carbohydrate antigen 19-9 level. Mucinous cystadenocarcinoma (MCC) was diagnosed pathologically based on distal pancreatectomy. A diagnosis of male MCN/MCC is often delayed, which may lead to a poor prognosis. MCN infection is also rare and poorly recognized. We observed an atypical male case of MCN/MCC.

Clinical significance of stromal ER and PR expression in periampullary adenocarcinoma

BACKGROUND

Tamoxifen treatment has previously been reported to confer life-prolonging effects in patients with advanced pancreatic cancer, and most evidently so in women. None of these trials did however include biomarkers, and the relevance of female hormone signaling in pancreatic or other periampullary adenocarcinoma remains largely unexplored. The aim of this study was to examine the extent and potential clinical significance of estrogen receptor-α (ER) and progesterone receptor (PR) expression in pancreatic and other periampullary cancers.

METHODS

ER and PR expression was examined using immunohistochemistry on tissue microarrays with primary tumors from a retrospective consecutive cohort of 175 patients with resected periampullary adenocarcinoma, with long-term clinical follow-up. Non-parametric and Chi square tests were applied to examine the associations of stromal ER and PR expression with patient and tumor characteristics. Kaplan-Meier analysis and log rank test were applied to illustrate survival differences in relation to ER and PR expression. Cox regression proportional hazards models were applied to examine the associations between investigative factors and risk of death and recurrence, and to test for interactions between KRAS mutation status and hormone receptor expression in relation to survival.

RESULTS

Expression of both ER and PR was more frequent in the tumor-associated stroma than in the epithelium. A significant prognostic interaction, independent of tumor morphology, was found between stromal PR expression and KRAS mutation status in relation to both overall and recurrence-free survival (pinteraction = 0.026 and pinteraction = 0.005), in particular in women (pinteraction = 0.002 and pinteraction = 0.005). Specifically, stromal PR expression was associated with a prolonged survival in patients with KRAS-mutated tumors, whereas the opposite was seen for KRAS wild-type tumors. The prognostic value of ER positivity was limited to the subgroup of women with tumors of pancreatic origin.

CONCLUSIONS

These results demonstrate that stromal PR rather than ER expression, together with KRAS mutation status, provides long-term prognostic information in patients with periampullary adenocarcinoma. Further study into the mechanistic basis for these observations may unveil important clues to the pathogenesis of these cancers and open up for the discovery of novel treatment options.

Diagnosis and management of pancreatic cystic neoplasms: current evidence and guidelines

Pancreatic cystic neoplasms (PCN) are a heterogeneous group of pancreatic cysts that include intraductal papillary mucinous neoplasms, mucinous cystic neoplasms, serous cystic neoplasms and other rare cystic lesions, all with different biological behaviours and variable risk of progression to malignancy. As more pancreatic cysts are incidentally discovered on routine cross-sectional imaging, optimal surveillance for patients with PCN is becoming an increasingly common clinical problem, highlighting the need to balance cancer prevention with the risk of (surgical) overtreatment. This Review summarizes the latest developments in the diagnosis and management of PCN, including the quality of available evidence. Also discussed are the most important differences between the PCN guidelines from the American Gastroenterological Association, the International Association of Pancreatology and the European Study Group on Cystic Tumours of the Pancreas, including diagnostic and follow-up strategies and indications for surgery. Finally, new developments in the management of patients with PCN are addressed.

From somatic mutation to early detection: insights from molecular characterization of pancreatic cancer precursor lesions

Pancreatic cancer arises from noninvasive precursor lesions, including pancreatic intraepithelial neoplasia (PanIN), intraductal papillary mucinous neoplasm (IPMN), and mucinous cystic neoplasm (MCN), which are curable if detected early enough. Recently, these types of precursor lesions have been extensively characterized at the molecular level, defining the timing of critical genetic alterations in tumorigenesis pathways. The results of these studies deepen our understanding of tumorigenesis in the pancreas, providing novel insights into tumor initiation and progression. Perhaps more importantly, they also provide a rational foundation for early detection approaches that could allow clinical intervention prior to malignant transformation. In this review, we summarize the results of comprehensive molecular characterization of PanINs, IPMNs, and MCNs and discuss the implications for cancer biology as well as early detection. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Pancreatic Ductal Adenocarcinoma and Its Precursor Lesions: Histopathology, Cytopathology, and Molecular Pathology

Pancreatic ductal adenocarcinoma is one of the most aggressive malignant neoplasms with poor outcomes. At the time of diagnosis, the disease is usually at an advanced stage and only a minority is eligible for surgical resection. To improve the prognosis, it is essential to diagnose and treat the disease in an early stage before its progression into an invasive disease. This article reviews clinical features, histopathology, cytopathology, and molecular alterations of pancreatic ductal adenocarcinoma and its precursors. Moreover, we review a recently updated two-tier classification system for precursor lesions, new findings in premalignant cystic neoplasms, and recently updated staging criteria for invasive carcinoma based on the Cancer Staging Manual, eighth edition, from the American Joint Committee on Cancer. Finally, we discuss the potential clinical applications of the rapidly growing molecular and genetic information of pancreatic cancer and its precursors.

Multiple KRAS mutations in the non-mucinous epithelial lining in the majority of mucinous cystic neoplasms of the pancreas

AIMS

Mucinous cystic neoplasms (MCNs) of the pancreas are cystic neoplasms lined by mucinous lining epithelium (MLE) with associated ovarian-type stroma. Although a non-MLE (NMLE) can be observed in some MCNs, whether cystic neoplasms with ovarian-type stroma and NMLE should be classified as MCNs or separately designated is debated.

METHODS AND RESULTS

To test this, NMLEs were defined as flat or cuboidal epithelial cells without intracytoplasmic mucin. A total of 112 MCNs were reviewed, and the epithelium was classified as NMLE or MLE. A total of 110 females and two males with a mean age of 46.5 ± 12.3 years were included in this study. At least focal NMLE was noted in 76.8% (86/112) of MCNs. The mean percentage of the neoplastic epithelium that was NMLE in these 86 cases was 46%. NMLE was predominant (>50%) in 38.4% (43/112) of cases. MCNs with NMLE were smaller (42 ± 21 mm) than those with MLE (60 ± 36 mm, P < 0.001), and all NMLEs had low-grade dysplasia. Twelve MCNs with NMLE or MLE were selected for KRAS mutation analysis with droplet digital polymerase chain reaction after laser capture microdissection. All 12 MCNs showed multiple types of KRAS mutation, which were detected in 92% (11/12) of NMLE foci and 89% (8/9) of MLE foci. Predominant NMLE was common in small MCNs with low-grade dysplasia.

CONCLUSIONS

Clonal KRAS mutations were observed in both NMLE and MLE, supporting the hypothesis that MCNs with NMLE should be classified as MCNs.

Diagnostic ability of artificial intelligence using deep learning analysis of cyst fluid in differentiating malignant from benign pancreatic cystic lesions

The diagnosis of pancreatic cystic lesions remains challenging. This study aimed to investigate the diagnostic ability of carcinoembryonic antigen (CEA), cytology, and artificial intelligence (AI) by deep learning using cyst fluid in differentiating malignant from benign cystic lesions. We retrospectively reviewed 85 patients who underwent pancreatic cyst fluid analysis of surgical specimens or endoscopic ultrasound-guided fine-needle aspiration specimens. AI using deep learning was used to construct a diagnostic algorithm. CEA, carbohydrate antigen 19-9, carbohydrate antigen 125, amylase in the cyst fluid, sex, cyst location, connection of the pancreatic duct and cyst, type of cyst, and cytology were keyed into the AI algorithm, and the malignant predictive value of the output was calculated. Area under receiver-operating characteristics curves for the diagnostic ability of malignant cystic lesions were 0.719 (CEA), 0.739 (cytology), and 0.966 (AI). In the diagnostic ability of malignant cystic lesions, sensitivity, specificity, and accuracy of AI were 95.7%, 91.9%, and 92.9%, respectively. AI sensitivity was higher than that of CEA (60.9%, p = 0.021) and cytology (47.8%, p = 0.001). AI accuracy was also higher than CEA (71.8%, p < 0.001) and cytology (85.9%, p = 0.210). AI may improve the diagnostic ability in differentiating malignant from benign pancreatic cystic lesions.

The epithelial-mesenchymal transition induces aggressivity of mucinous cystic neoplasm of the pancreas with neuroendocrine component: An immunohistochemistry study

BACKGROUND

Pancreatic mucinous cystic neoplasms (MCN) are rare tumors that are usually diagnosed in females.

MATERIALS AND METHODS

In our department, only four of the 109 consecutive cases of pancreatic tumors (3.67%) were diagnosed as MCNs. In this report, we present the characteristics of these four specific cases which also showed unusual HER-2 positivity and neuroendocrine differentiation.

RESULTS

The four MCNs were diagnosed in patients with ages between 46 and 75 years. Other clinical particularities were the following: one benign case, splenic rupture as result of a giant cystic tumor on the tail of the pancreas directly invading the spleen in the second one, metastases in the accessory spleen in the third one and invasion of the abdominal vessels in the fourth case. In all of these cases, the ovarian-like stroma tested positivity for calretinin, progesterone receptor (PR) and, in cases 2 and 3, for AE1/AE3 keratin. The malignant tumor cells were marked by carcinoembryonic antigen, HER-2, maspin, PR and the neuroendocrine markers synaptophysin, CD56, and neuron-specific enolase.

CONCLUSIONS

These cases highlight the unusually aggressive behavior of pancreatic MCN with invasive carcinomas that share mixed exo- and endocrine components and show epithelial-mesenchymal transition.

Prognostic value of progesterone receptor in solid pseudopapillary neoplasm of the pancreas: evaluation of a pooled case series

Background

The role of progesterone receptor (PR) has been reported in a series of pancreatic cysts. However, the relationship between PR and prognosis of solid pseudopapillary neoplasm of the pancreas (SPNP) has not been elucidated so far. The aim of our study was to evaluate the prognostic value of PR in SPNP.

Methods

A total of 76 patients with SPNP treated in our institution from January 2012 to December 2017 were included. Demographic parameters, laboratory data, pathologic information and clinical outcomes were analyzed by the use of survival analysis. In addition, a pooled case series was performed to evaluate the results.

Results

The institutional data included 76 patients (17 male and 59 female) ranging from 8 to 90 years (median, 30 years) in age. Kaplan-Meier survival analysis confirmed negative PR result was significantly associated with poorer disease-free survival (DFS) and disease-specific survival (DSS) (both P < 0.001). In the pooled analysis, a total of 62 studies comprising 214 patients with SPNP were included. After multivariable cox analysis, negative PR result remained an independent prognostic factor for SPNP (DFS HR: 14.50, 95% CI: 1.98–106.05, P = 0.008; DSS HR: 9.15, 95% CI: 1.89–44.17, P = 0.006).

Conclusion

Our results indicated the role of PR in predicting adverse outcome of patients with SPNP and negative PR result may serve as a potential prognostic factor.

Electronic supplementary material

The online version of this article (10.1186/s12876-018-0914-8) contains supplementary material, which is available to authorized users.

Risk of malignancy in resected pancreatic mucinous cystic neoplasms

BACKGROUND

Pancreatic mucinous cystic neoplasms (MCNs) are rare mucin-producing cystic tumours defined by the presence of ovarian-type stroma. MCNs have a malignant potential and thus surgery is frequently performed. The aim of this cohort study was to define better the criteria for surgical resection in patients with MCN.

METHODS

This multicentre retrospective study included all resected MCNs between 2003 and 2015 in participating centres. Lesions without ovarian-type stroma were excluded. Patient characteristics, preoperative findings, histopathology findings and follow-up data were recorded.

RESULTS

The study included 211 patients; their median age was 53 (range 18-82) years, and 202 (95·7 per cent) were women. Median preoperative tumour size was 55 (range 12-230) mm. Thirty-four of the 211 (16·1 per cent) were malignant, and high-grade dysplasia (HGD) was found in a further 13 (6·2 per cent). One-third of MCNs in men were associated with invasive cancer, compared with 15·3 per cent in women. Five cases of malignant transformation occurred in MCNs smaller than 4 cm. All cases of malignancy or HGD were associated with symptoms or features of concern on preoperative cross-sectional imaging. In multivariable analysis, raised carbohydrate antigen 19-9 (odds ratio (OR) 10·54, 95 per cent c.i. 2·85 to 218·23; P < 0·001), tumour size (OR 4·23, 3·02 to 11·03; P = 0·001), mural nodules (OR 3·55, 1·31 to 20·55; P = 0·002) and weight loss (OR 3·40, 2·34 to 12·34; P = 0·034) were independent factors predictive of malignant transformation.

CONCLUSIONS

Small indeterminate MCNs with no symptoms or features of concern may safely be observed as they have a low risk of malignant transformation.