An Algorithmic Immunohistochemical Approach to Define Tumor Type and Assign Site of Origin

Metastatic upper tract urothelial carcinoma with nest-like features presenting as malignant pleural effusion

Metastatic urothelial carcinoma is a rare cause of pleural effusions. We report a case of urothelial carcinoma of the upper urinary tract in an oldest-old male patient, a smoker, with situs inversus totalis, that presented uniquely with malignant pleural effusion at presentation without evidence of a primary tumor on imaging. Cytological smears of the massive left pleural effusion revealed epithelioid neoplastic cells arranged in short cords, small-to-large clusters, and raspberry-like morules, mimicking mesothelioma; cell block preparations highlighted the presence of tubules and nest-like structures. The tumor cells showed a high nuclear-to-cytoplasmic ratio, nuclear grooves, and mitotic figures. Cytomorphologic features coupled with the immunophenotype of neoplastic cells (p63, GATA3, and uroplakin II positive) allowed the diagnosis of metastatic urothelial carcinoma and a possible nested subtype. These findings were supported by a total body computed tomography (CT) showing no evidence of a mass in the bladder or elsewhere in the urinary tract but a concentric parietal thickening of the proximal left ureter, suggesting malignancy. To our knowledge, a malignant effusion as a primary manifestation of urothelial carcinoma with nest-like features originating in the upper urinary tract has never been described previously. Our case focuses on the value of cell block in the working-up of neoplastic effusions by revealing the architectural pattern of an uncommon malignancy and the correlation between cytopathology and imaging gross findings to reach an accurate diagnosis.

Incidental diagnosis of primary appendiceal signet-ring cell adenocarcinoma after appendectomy for acute appendicitis: a case report

Introduction

Appendiceal signet-ring cell adenocarcinoma (ASCA) is rare and more aggressive in malignant appendiceal neoplasms. The presentation can be appendicitis, which is lack of specific symptom and makes early diagnosis difficult. There is no effective surveillance. Prognosis largely relies on timely detection. We report a case of ASCA incidentally diagnosed through pathological examination after appendectomy for appendicitis.

Case presentation

The patient presented to our department with a progressive right lower quadrant abdominal pain lasting for 3 days. Physical examination revealed rigidity, tenderness, and rebound tenderness on the right lower quadrant. A computed tomography scan showed a thickened, inflamed appendix with peri-appendiceal fat stranding without noticeable appendiceal mass at initial evaluation. The diagnosis was considered acute appendicitis, and an appendectomy was performed. The appendix was inflamed, gangrenous and perforated, and no mass was found during the surgery. Surgical specimen was sent for physiological examination, which incidentally detected signet-ring cell in H&E staining. And immunohistochemistry confirmed the diagnosis of ASCA with small amount of neuroendocrine neoplasms.

Conclusion

Early diagnosis of ASCA can incidentally be made on pathological specimen following appendectomy for appendicitis. A routine pathological examination should be emphasized, and appendectomy may not be the endpoint of the treatment. Hemicolectomy and adjuvant therapy might ensue upon the diagnosis of appendiceal neoplasm. The poor prognosis of ASCA makes a timely diagnosis significant. Basic research is promising to unravel the molecular mechanisms of pathogenesis, finding typical tumor markers for screening and novel effective therapies for advanced cases.

Implications of MTHFD2 expression in renal cell carcinoma aggressiveness

Renal cell carcinoma (RCC) is the most common type of cancer in kidney and is often diagnosed in advanced stages. Until now, there is no reliable biomarker to assess tumor prognosis during histopathological diagnosis. The Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) overexpression has been suggested as prognostic indicator for RCC, however, its protein profile needs to be clarified. This study investigated the MTHFD2 expression in different RCC cohorts, associating it with tumor characteristics and prognostic factors. Gene expression comparisons between non-neoplastic (NN) and tumor samples, as well as patients' survival analysis, were assessed using KM-Plotter tool. MTHFD2 protein pattern was evaluated in 117 RCC by immunohistochemistry and associations with prognosis, clinical and pathological data were investigated. The tumors exhibited higher MTHFD2 transcript levels than NN, being even higher in the metastatic group. Opposite gene expression patterns were found among clear cell renal cell carcinoma (ccRCC) and pappilary renal cell carcinoma (pRCC) subtypes, showing higher and lower expressions compared to NN samples respectively. Overexpression was associated with shorter overall survival for ccRCC and pRCC subtypes, and shorter recurrence-free survival for pRCC. The immunolabeling profile varied according to tumor subtypes, with lower intensity and expression scores in ccRCC compared to pRCC and to chromophobe renal cell carcinoma (chRCC). MTHFD2 protein expression was associated with larger tumors and higher Fuhrman grades. Although prognostic value of protein immunostaining was not confirmed, patients with higher MTHFD2 tended to have lower survival rates in the pRCC group. The results highlight MTHFD2 different patterns according to RCC histological subtypes, revealing marked variations at both the genetic and protein levels. The mRNA indicated tumor prognosis, and greater expression in the tumor samples. Although MTHFD2 immunolabeling suggests tumor aggressiveness, it needs to be validated in other cohorts as potential prognostic factor.

Aberrant expression of GATA3 in metastatic adenocarcinoma of the prostate: an important pitfall

AIMS

The distinction of high-grade prostate cancer (PCa) from poorly differentiated urothelial carcinoma (UC) can be somewhat challenging on clinical and morphological grounds alone, yet it is of great importance for prognostication and choice of treatment. GATA3 is a useful immunohistochemical marker to confirm urothelial origin. However, recent works report strong GATA3 immunoexpression in primary high-grade PCa. The aim of this study was to explore GATA3 expression specifically in metastatic PCa.

METHODS AND RESULTS

The pathology databases of four tertiary institutions were queried for cases of metastatic PCa. Available slides and clinical records were reviewed by experienced genitourinary pathologists. Prostatic markers (PSA, PSAP, NKX3.1) and GATA3 immunohistochemistry were performed. A total of 163 metastatic PCa cases were included. At least one prostate marker was positive in each case of non-regional distant metastasis, confirming prostatic origin. GATA3 strong staining was found in four (2.5%) cases: two liver, one bone and one non-regional lymph-node metastases. All four patients had Grade Group 5 PCa at the initial diagnosis. The metastatic prostatic adenocarcinomas were solid, either with no gland formation (n = 3) or with only focal cribriforming (n = 1).

CONCLUSIONS

To our knowledge, this is the first study exploring GATA3 expression specifically in metastatic PCa. Despite being infrequent, GATA3 positivity in high-grade PCa may lead to misdiagnosis, with clinical implications. We recommend a panel of immunohistochemical markers, both prostatic and urothelial, for ruling out UC, either in primary tumour samples or in the event of metastases of unknown primary, when a genitourinary origin is suspected.

The role of fine-needle aspiration biopsy in the diagnosis of malignant tumors

Cytopathology and histopathology play a key role in the process of diagnosing oncological diseases and premalignant conditions. Fine-needle aspiration (FNA) is one of the techniques used for obtaining biopsy of a wide variety of body tissues, causing patients minimal discomfort. Therefore, it is often considered to be the best strategy for investigating and diagnosing some precancerous or potential malignant lesions. Being successful as a means of confirming the clinical suspicion of metastatic recurrence in the cases of an already known cancer, the interest has further focused on the preliminary diagnosis of various types of benign or malignant tumors. In cases of inoperable tumors, this technique is useful for formulating the final diagnosis. FNA biopsy proved its effectiveness as a highly accurate, cost-effective, and safe technique, with potential high diagnostic yield. Immunohistochemistry, used as an additional tool to classical histopathological examination, remains a very practical and reliable technique that promises good results especially in determining the site of origin within metastatic disease.

Role of intraoperative touch imprint cytology and immunohistochemistry in the diagnosis of metastatic malignancies in the central nervous system: Cyto-histomorphological findings and differential diagnosis

BACKGROUND

Brain metastases (BMs) are intracranial neoplasms that are more common in adults than primary brain tumors, causing significant mortality and morbidity in cancer patients. This study aimed to evaluate the definitive histopathological diagnosis using touch imprint cytology and the importance and use of immunohistochemistry in the diagnosis of primary origin.

METHOD

Cytological, paraffin section, and immunohistochemical study slides of all metastatic brain tumors consecutively consulted at the pathology department between 2018 and 2023 were evaluated. The sensitivity, specificity, and accuracy of patients' diagnostic results who underwent imprint cytology were compared based on the final diagnosis histopathological report.

RESULTS

A total of 45 patients with and without intraoperative consultation were included in the study. The definitive histopathologic diagnosis and the diagnostic accuracy rate of imprint cytology for distinguishing glial and metastatic tumors on paraffin sections was 100%. Immunohistochemistry was performed in all patients (except one patient; immediate exitus) and histological classification of the primary tumor was performed by analysis of clinical findings and biomarkers. The primary origins of metastatic tumors were often lung and breast, with adenocarcinoma subtype histomorphology, cerebral hemispheres, and discrete foci of metastasis.

CONCLUSION

TPs is a simple and rapid technique that supports diagnosis in intraoperative neuropathology and is a very cost-effective procedure. The pathologist's experience is the key factor in the diagnosis and reduces the need for a frozen section. In our series, the final histopathologic correlation of imprint cytology in the diagnosis of primary and metastatic tumors is 100%.

Diagnosis of a SMARCA4-deficient undifferentiated tumor using multigene panel testing: A case report

Key Clinical Message

SMARCA4-deficient thoracic carcinoma is a malignant tumor that may present as cancer of unknown primary. This tumor is refractory and requires a novel approach. In addition to identifying therapeutic targets, multigene panel testing can reveal novel genetic mutations, leading to more pathologically relevant diagnoses and appropriate tumor care.

Abstract

SMARCA4-deficient undifferentiated tumors are characterized by SMARCA4 inactivation. We present a case of a 74-year-old man with an undifferentiated tumor and a novel SMARCA4 mutation detected using multigene panel testing. The tumor was multiagent and refractory to three chemotherapy lines. The test results helped guide appropriate medical management.

Methylation status, mRNA and protein expression of the SMAD4 gene in patients with non-melanocytic skin cancers

BACKGROUND

SMAD4 is a potent tumor suppressor. SMAD4 loss increases genomic instability and plays a critical role in the DNA damage response that leads to skin cancer development. We aimed to investigate SMAD4 methylation effects on mRNA and protein expression of SMAD4 in cancer and healthy tissues from patients with basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (cSCC), and basosquamous skin cancer (BSC).

METHODS AND RESULTS

The study included 17 BCC, 24 cSCC and nine BSC patients. DNA and RNA were isolated from cancerous and healthy tissues following punch biopsy. Methylation-specific polymerase chain reaction (PCR) and real-time quantitative PCR methods were used to examine SMAD4 promoter methylation and SMAD4 mRNA levels, respectively. The percentage and intensity of staining of the SMAD4 protein were determined by immunohistochemistry. The percentage of SMAD4 methylation was increased in the patients with BCC (p = 0.007), cSCC (p = 0.004), and BSC (p = 0.018) compared to the healthy tissue. SMAD4 mRNA expression was decreased in the patients with BCC (p˂0.001), cSCC (p˂0.001), and BSC (p = 0.008). The staining characteristic of SMAD4 protein was negative in the cancer tissues of the patients with cSCC (p = 0.00). Lower SMAD4 mRNA levels were observed in the poorly differentiated cSCC patients (p = 0.001). The staining characteristics of the SMAD4 protein were related to age and chronic sun exposure.

CONCLUSIONS

Hypermethylation of SMAD4 and reduced SMAD4 mRNA expression were found to play a role in the pathogenesis of BCC, cSCC, and BSC. A decrease in SMAD4 protein expression level was observed only in cSCC patients. This suggests that epigenetic alterations to the SMAD4 gene are associated with cSCC.

TRIAL REGISTRATION

The name of the trial register: SMAD4 Methylation and Expression Levels in Non-melanocytic Skin Cancers; SMAD4 Protein Positivity. The registration number: NCT04759261 ( https://clinicaltrials.gov/ct2/results?term=NCT04759261 ).

Lessons Learned, Challenges Taken, and Actions Made for "Precision" Immunohistochemistry. Analysis and Perspectives From the NordiQC Proficiency Testing Program

Immunohistochemistry (IHC) has for decades been an integrated method within pathology applied to gain diagnostic, prognostic, and predictive information. However, the multimodality of the analytical phase of IHC is a challenge to ensure the reproducibility of IHC, which has been documented by external quality assessment (EQA) programs for many biomarkers. More than 600 laboratories participate in the Nordic immunohistochemical Quality Control EQA program for IHC. In the period, 2017-2021, 65 different biomarkers were assessed and a total of 31,967 results were evaluated. An overall pass rate of 79% was obtained being an improvement compared with 71% for the period, 2003-2015. The pass rates for established predictive biomarkers (estrogen receptor, progesterone receptor, and HER2) for breast carcinoma were most successful showing mean pass rates of 89% to 92%. Diagnostic IHC biomarkers as PAX8, SOX10, and different cytokeratins showed a wide spectrum of pass rates ranging from 37% to 95%, mean level of 75%, and attributed to central parameters as access to sensitive and specific antibodies but also related to purpose of the IHC test and validation performed accordingly to this. Seven new diagnostic biomarkers were introduced, and all showed inferior pass rates compared with the average level for diagnostic biomarkers emphasizing the challenge to optimize, validate, and implement new IHC biomarkers. Nordic immunohistochemical Quality Control operates by "Fit-For-Purpose" EQA principles and for programmed death-ligand 1, 2 segments are offered aligned to the "3-dimensional" approach-bridging diagnostic tests, drugs to be offered, and diseases addressed. Mean pass rates of 65% and 79% was obtained in the 2 segments for programmed death-ligand 1.

Expert Consensus Practice Recommendations of the North American Neuroendocrine Tumor Society for the management of high grade gastroenteropancreatic and gynecologic neuroendocrine neoplasms

High-grade neuroendocrine neoplasms are a rare disease entity and account for approximately 10% of all neuroendocrine neoplasms. Because of their rarity, there is an overall lack of prospectively collected data available to advise practitioners as to how best to manage these patients. As a result, best practices are largely based on expert opinion. Recently, a distinction was made between well-differentiated high-grade (G3) neuroendocrine tumors and poorly differentiated neuroendocrine carcinomas, and with this, pathologic details, appropriate imaging practices and treatment have become more complex. In an effort to provide practitioners with the best guidance for the management of patients with high-grade neuroendocrine neoplasms of the gastrointestinal tract, pancreas, and gynecologic system, the North American Neuroendocrine Tumor Society convened a panel of experts to develop a set of recommendations and a treatment algorithm that may be used by practitioners for the care of these patients. Here, we provide consensus recommendations from the panel on pathology, imaging practices, management of localized disease, management of metastatic disease and surveillance and draw key distinctions as to the approach that should be utilized in patients with well-differentiated G3 neuroendocrine tumors vs poorly differentiated neuroendocrine carcinomas.

Diagnostic algorithm for challenging blue cell sinonasal carcinoma

The newly emerging sinonasal carcinomas have demonstrated diverse morphologies and specific molecular rearrangements along with deviant clinical behavior from conventional counterparts. We aim to propose a diagnostic algorithm that is based on molecular findings of each sinonasal cancer and is considering the new entities has been called upon. Such a diagnostic algorithm should help diagnostic pathologists establish a diagnosis of a challenging sinonasal blue cell carcinomas and researchers performing retrospective analysis of archival cases. Along with consulting our archival cases, literature mining was conducted to retrieve the immunohistochemical and molecular findings regarding the newly emerging entities. Our proposed algorithm distinguishes poorly differentiated (non) keratinizing SNSCC, from anaplastic myoepithelial carcinoma, NUT midline carcinoma, SMARCB1/SMARCA4-deficient teratocarcinosarcoma, SMARCB1/SMARCA4-deficient carcinosarcoma, olfactory neuroblastoma, sinonasal undifferentiated carcinoma, HPV-related multiphenotypic sinonasal carcinoma and other adenocarcinomas. By incorporating morphologic features, immunohistochemical markers, and molecular investigations, the algorithm enhances the accuracy of diagnosis, particularly in cases where comprehensive molecular testing is not readily available. This algorithm serves as a valuable resource for pathologists, facilitating the proper diagnosis of sinonasal malignancies and guiding appropriate patient management.

p53 as Exemplar Next-Generation Immunohistochemical Marker: A Molecularly Informed, Pattern-Based Approach, Methodological Considerations, and Pan-Cancer Diagnostic Applications

This review is based on a webinar I presented for the International Society for Immunohistochemistry and Molecular Morphology (ISIMM) in February 2022. It is intended that all ISIMM webinars will ultimately be published in AIMM as review articles. This work is also dedicated to Clive Taylor, who has deeply impacted my career. It presents a molecularly informed, pattern-based approach to p53 immunohistochemistry interpretation, methodological considerations (ie, antibody selection, optimization, validation, controls, and external quality assessment), and pan-cancer diagnostic applications, including those drawn from gastrointestinal, genitourinary, gynecological, neuroendocrine, hematologic, and neuropathology. It intends to prove the thesis statement that p53 is an exemplar next-generation immunohistochemical marker "born" ahead of its time.

Appendiceal Signet Ring Cell Carcinoma: An Atypical Cause of Acute Appendicitis-A Case Study and Review of Current Knowledge

Appendiceal signet ring cell carcinoma (ASRCC) is a rare and aggressive form of appendiceal cancer, often presenting with nonspecific symptoms that overlap with acute appendicitis. Early diagnosis and appropriate management are crucial for improving patient outcomes in these rare malignancies. This case report and literature review aims to raise awareness among clinicians about ASRCC of the appendix as a cause of acute appendicitis and highlight the importance of considering this diagnosis in patients with atypical presentations or unexpected histopathological findings. We present a 65-year-old female patient with ASRCC who underwent successful surgical treatment and remains disease-free at the one-year follow-up. It also highlights the necessity of early detection and appropriate treatment in order to improve patient outcomes. In addition, a comprehensive literature review is provided, discussing the clinical presentation, histopathological characteristics, potential pathogenesis, treatment options, and prognosis of ASRCC.

Solitary Plasmacytoma of the Breast: A Case of an Uncommon Breast Neoplasm

Plasmacytoma is a rare cancer that originates from a single plasma cell and is characterized by the abnormal proliferation of monoclonal plasma cells. It is typically localized in a single area of the body, most commonly in the bone or soft tissue. Solitary plasmacytoma can be further classified as either solitary plasmacytoma of bone (SPB) or solitary extramedullary plasmacytoma (SEP or EMP). Diagnosis may be delayed in symptomatically silent plasmacytomas, but early diagnosis and prompt treatment are crucial for the management of this disease. The mean age for patients with plasmacytoma varies depending on the specific type of plasmacytoma, but generally, it is more common in older adults. Soft tissue plasmacytomas are uncommon, and plasmacytomas manifesting within the breast are extremely rare, especially when they are not a manifestation of multiple myeloma (MM). This report presents a case of SEP of the breast in a 79-year-old female patient. This rare disease needs to be studied further in terms of long-term survival and disease progression to MM. By raising awareness and understanding of plasmacytoma, we aim to improve outcomes and quality of life for patients affected by this disease.

A Spectrum of Histomorphological and Immunohistochemical Expression Profiles of S-100, CD56 and Calretinin in Benign Peripheral Nerve Sheath Tumours

INTRODUCTION

 Peripheral nerve sheath tumours comprise benign tumours; namely schwannomas and neurofibromas, and only rarely comprise hybrid benign tumours and their malignant counterpart, malignant peripheral nerve sheath tumours (MPNST). There may be diagnostic difficulties in histopathology analysis, especially in core needle biopsies where there is a limited amount of tissue. Immunohistochemistry (IHC) can play a beneficial role, especially in atypical and cellular histological variants and rarely hybrid tumours.

METHODS

 A total of 45 cases of benign peripheral nerve sheath tumours were included in the study; there were 27 cases of neurofibroma including variants like plexiform and cellular neurofibromas and 18 cases of schwannomas including variants like ancient schwannoma and cellular schwannoma. Immunohistochemical staining (IHC) on these tumour tissues using S-100, CD56 and calretinin was done and scoring was done based on extent and intensity.

RESULTS AND DISCUSSION

 No significant differences were observed between neurofibromas and schwannomas on patient age and anatomical locations of these tumours. IHC results did not show statistically significant patterns of expression of S-100 protein between the schwannoma and neurofibromas groups (p=0.75). CD56 protein was expressed strongly (3+) in 90% of cases of schwannoma and negative in 86% of neurofibromas, the differential expression between the two groups was found to be statistically significant (p <0.0001). Calretinin was positive in 39% of schwannomas including one case of cellular schwannoma and negative in all (100%) cases of neurofibroma while the differential expression of calretinin between schwannoma and neurofibroma groups was found to be statistically significant (p < 0.005).

CONCLUSION

Our study shows that S-100 does not show differential expression between schwannomas and neurofibromas. CD56 could be a potentially useful IHC marker to aid in the diagnosis of peripheral nerve sheath tumours with significantly higher expression in schwannomas compared to neurofibromas. Calretinin was also found to be preferentially expressed in schwannomas, though the difference is statistically significantly lower compared to CD56. A panel of all these markers could be used for accurate diagnosis.

[CUP syndrome-diagnostics from the perspective of pathology]

PROBLEM

Histologic and immunohistologic workup of tumor material from metastases of a previously unknown primary tumor is important for identifying their origin, but is often insufficient for this purpose without clinical oncologic and radiologic evaluation.

PROCEDURE

In the initial cancer of unknown primary (CUP) situation, histologic and immunohistochemical workup together with clinicoradiologic correlations contribute significantly to the identification of the primary tumor. There are now accepted guidelines to follow when there is an initial CUP situation. Molecular diagnostic tools can be used to investigate changes at the nucleic acid level, which can provide clues about the primary tumor, including potential targets for therapy. If, despite broad and interdisciplinary diagnostics, it is not possible to identify the primary tumor, the diagnosis is CUP syndrome. If a true CUP situation is present, it is important to assign the tumor to a tumor class or a specific therapy-sensitive subgroup as best as possible so that the best possible treatment can be given. However, for a final assignment to a primary tumor or a final classification as CUP, a comparison with medical oncological and imaging findings is indispensable.

CONCLUSION

When CUP is suspected, close interdisciplinary collaboration between pathology, medical oncology, and imaging is essential to achieve a viable classification as CUP or identification of a presumptive primary tumor, in the interest of providing the most specific and effective therapy for affected individuals.

Inhibition of serotonin biosynthesis in neuroendocrine neoplasm suppresses tumor growth in vivo

Small bowel neuroendocrine tumors (SBNETs) originate from enterochromaffin cells in the intestine which synthesize and secrete serotonin. SBNETs express high levels of tryptophan hydroxylase 1 (Tph1), a key enzyme in serotonin biosynthesis. Patients with high serotonin level may develop carcinoid syndrome, which can be treated with somatostatin analogues and the Tph1 inhibitor telotristat ethyl in severe cases. Although the active drug telotristat can efficiently reduce serotonin levels, its effect on tumor growth is unclear. This study determined the effect of serotonin inhibition on tumor cell growth in vitro and in vivo . The levels of Tph1 in various neuroendocrine neoplasms (NENs) were determined and the biological effects of Tph1 inhibition in vitro and in vivo using genetic and pharmacologic approaches was tested. Gene and protein expression analyses were performed on patient tumors and cancer cell lines. shRNAs targeting TPH1 were used to create stable knockdown in BON cells. Control and knockdown lines were assessed for their growth rates in vitro and in vivo , angiogenesis potential, serotonin levels, endothelial cell tube formation, tumor weight, and tumor vascularity. TPH1 is highly expressed in SBNETs and many cancer types. TPH1 knockdown cells and telotristat treated cells showed similar growth rates as control cells in vitro . However, TPH1 knockdown cells formed smaller tumors in vivo and tumors were less vascularized. Although Tph1 inhibition with telotristat showed no effect on tumor cell growth in vitro , Tph1 inhibition reduced tumor formation in vivo . Serotonin inhibition in combination with other therapies is a promising new avenue for targeting metabolic vulnerabilities in NENs.

Investigating the inhibitory and penetrating properties of three novel anticancer and antimicrobial scorpion peptides via molecular docking and molecular dynamic simulation

The two types of bladder cancer, muscle invasive and non-muscle invasive (NMIBC), are among the most prevalent cancers worldwide. Despite this, even though muscle-invasive bladder cancer is more deadly, NMIBC requires more therapy due to a greater recurrence rate and more extended and expensive care. Immunotherapy, intravesical chemotherapy, cystoscopy, and transurethral resection (TUR) are among the treatments available. Crude scorpion venomand purified proteins and peptides, can suppress cancer metastasis in an in vitro or in vivo context, suppress cancer growth, halt the cell cycle, and cause cell apoptosis, according to an increasing number of experimental and preclinical studies. In this research, three novels discovered peptides (P2, P3 and P4. ProteomeXchange: PXD036231) from Buthotus saulcyi and, Odontobuthus doriae scorpions were used along with a peptide called pantinin (as a control). The phylogenetic tree showed that the peptides belong to Chaperonin HSP60, Chrysophsin2 and Pheromone-binding protein2, respectively. These peptides were docked with four known antigens, BAGE, BLCAP, PRAME and ROR1 related to bladder cancer and three bacterial antigens FliC, FliD and FimH to investigate their antimicrobial and anticancer properties. The results showed that peptides 2 and 3 have the best binding rate. The MD simulation results also confirmed the binding of peptides 2 and 3 to antigens. The penetration power of peptides 2 and 3 in the membrane of cancer cells and bacterial cells was also simulated, and the results of RMSD and PD confirmed it. QSAR suggests that peptides 2 and 3 can act as anti-cancer and anti-microbial peptides.Communicated by Ramaswamy H. Sarma.

Cell-free DNA methylation biomarker for the diagnosis of papillary thyroid carcinoma

BACKGROUND

Cell-free DNA (cfDNA) is being explored as biomarker for non-invasive diagnosis of cancer. We aimed to establish a cfDNA-based DNA methylation marker panel to differentially diagnose papillary thyroid carcinoma (PTC) from benign thyroid nodule (BTN).

METHODS

220 PTC- and 188 BTN patients were enrolled. Methylation markers of PTC were identified from patients' tissue and plasma by reduced representation bisulfite sequencing and methylation haplotype analyses. They were combined with PTC markers from literatures and were tested on additional PTC and BTN samples to verify PTC-detecting ability using targeted methylation sequencing. Top markers were developed into ThyMet and were tested in 113 PTC and 88 BTN cases to train and validate a PTC-plasma classifier. Integration of ThyMet and thyroid ultrasonography was explored to improve accuracy.

FINDINGS

From 859 potential PTC plasma-discriminating markers that include 81 markers identified by us, the top 98 most PTC plasma-discriminating markers were selected for ThyMet. A 6-marker ThyMet classifier for PTC plasma was trained. In validation it achieved an Area Under the Curve (AUC) of 0.828, similar to thyroid ultrasonography (0.833) but at higher specificity (0.722 and 0.625 for ThyMet and ultrasonography, respectively). A combinatorial classifier by them, ThyMet-US, improved AUC to 0.923 (sensitivity = 0.957, specificity = 0.708).

INTERPRETATION

The ThyMet classifier improved the specificity of differentiating PTC from BTN over ultrasonography. The combinatorial ThyMet-US classifier may be effective in preoperative diagnosis of PTC.

FUNDING

This work was supported by the grants from National Natural Science Foundation of China (82072956 and 81772850).

Real-world histopathological approach to malignancy of undefined primary origin (MUO) to diagnose cancers of unknown primary (CUPs)

The aim of this study is to envisage a streamlined pathological workup to rule out CUPs in patients presenting with MUOs. Sixty-four MUOs were classified using standard histopathology. Clinical data, immunocytochemical markers, and results of molecular analysis were recorded. MUOs were histologically subdivided in clear-cut carcinomas (40 adenocarcinomas, 11 squamous, and 3 neuroendocrine carcinomas) and unclear-carcinoma features (5 undifferentiated and 5 sarcomatoid tumors). Cytohistology of 7/40 adenocarcinomas suggested an early metastatic cancer per se. In 33/40 adenocarcinomas, CK7/CK20 expression pattern, gender, and metastasis sites influenced tissue-specific marker selection. In 23/40 adenocarcinomas, a "putative-immunophenotype" of tissue of origin addressed clinical-diagnostic examinations, identifying 9 early metastatic cancers. Cell lineage markers were used to confirm squamous and neuroendocrine differentiation. Pan-cytokeratins were used to confirm the epithelial nature of poorly differentiated tumors, followed by tissue and cell lineage markers, which identified one melanoma. In total, 47/64 MUOs (73.4%) were confirmed CUP. Molecular analysis, feasible in 37/47 CUPs (78.7%), had no diagnostic impact. Twenty CUP patients, mainly with squamous carcinomas and adenocarcinomas with putative-gynecologic-immunophenotypes, presented with only lymph node metastases and had longer median time to progression and overall survival (< 0.001), compared with patients with other metastatic patterns. We propose a simplified histology-driven workup which could efficiently rule out CUPs and identify early metastatic cancer.

All Together Now: Standardization of Nomenclature for Neuroendocrine Neoplasms across Multiple Organs

Neuroendocrine neoplasms (NENs) span virtually all organ systems and exhibit a broad spectrum of behavior, from indolent to highly aggressive. Historically, nomenclature and grading practices have varied widely across, and even within, organ systems. However, certain core features are recapitulated across anatomic sites, including characteristic morphology and the crucial role of proliferative activity in prognostication. A recent emphasis on unifying themes has driven an increasingly standardized approach to NEN classification, as delineated in the World Health Organization's Classification of Tumours series. Here, we review recent developments in NEN classification, with a focus on NENs of the pancreas and lungs.

An Appraisal of Immunohistochemical Stain Use in Hepatic Metastasis Highlights the Effectiveness of the Individualized, Case-Based Approach: Analysis of Data From a Tertiary Care Medical Center

CONTEXT.—

Liver biopsy plays an important role in the clinical management of metastases and often requires workup using immunohistochemical (IHC) markers, but the approach varies among institutions.

OBJECTIVE.—

To evaluate the utility of a morphologic pattern-based, individualized approach in the workup of hepatic metastases.

DESIGN.—

All liver biopsies with metastasis between 2015 and 2018 were identified from our institutional database and were reviewed. The morphologic pattern of the metastasis and IHC markers used in each case were recorded. The final identification of primary site of the tumor was assessed based on all the available clinicopathologic data. The academic ranking and practice pattern of the pathologist signing out the case were also recorded.

RESULTS.—

A total of 406 liver biopsies with metastasis were identified, and the cases were classified as adenocarcinoma (253 of 406; 62%), carcinoma not otherwise specified (12 of 406; 3%), neuroendocrine neoplasm (54 of 406; 13%), poorly differentiated carcinoma (43 of 406; 11%), nonepithelial tumor (24 of 406; 6%), and squamous cell carcinoma (20 of 406; 5%). The primary site was unknown in 39% (158 of 406) at the time of liver biopsy. A primary site was determined in 97% (395 of 406) of all cases, and only 3% (11 of 406) remained true carcinoma of unknown primary. The average number of IHC markers/case in patients with known primary was 2.6, compared with 5.9 with an initial unknown primary and 9.5 in cases of true carcinoma of unknown primary.

CONCLUSIONS.—

An individualized, case-based approach seems to be highly cost-effective and uses fewer IHC markers compared with preset panels that often comprise 10 or more IHC markers.

Scoring Systems for Immunohistochemistry in Urothelial Carcinoma

Immunohistochemistry is widely used in diagnostic and scientific analysis of urothelial carcinoma. Objective interpretation of staining results is mandatory for accuracy and comparability in diagnostic and therapeutic patient care as well as research.Herein we summarize and explain standardized microscopic evaluation and scoring approaches for immunohistochemical stainings. We focus on commonly used and generally feasible approaches for different cellular compartments and comment on their utility in diagnostics and research practice.

DIFFERENTIAL-DIAGNOSTIC INFORMATIVENESS OF THE MORPHOLOGICAL AND IMMUNOHISTOCHEMICAL STUDY OF PAROTID SALIVARY GLAND CYSTS

OBJECTIVE

The aim: To conduct a general analysis of the results of the study of the morphological and immunohistochemical structure of cysts of the parotid salivary glands.

PATIENTS AND METHODS

Materials and methods: Our study is based on the application of generally accepted, additional and special methods of examination, which concerns 21 patients who underwent surgical intervention to remove cystic formations of the parotid salivary gland.

RESULTS

Results: It was established that there are 2-3 HLA-DR+ cells per 100 epithelial cells located in the basal and subbasal layers in the form of their continuous ribbon and their moderate infiltration of tissues within the acinar epithelium. In the epithelium, CD3+ cells were also detected in the number of 1 to 7 per 100 epitheliocytes and they were the most numerous, along with HLA-DR+ cells. Instead, the presence of CD4+ and CD20+ cells was not detected in the epithelium, unlike the subepithelial layer, where they occupied significant areas. In turn, the infiltration of CD8+ cells of the epithelial layer was established in the amount from 1 to 7 per 100 epitheliocytes. A moderate number of them was also determined subepithelially, and they were single directly in the cyst wall.

CONCLUSION

Conclusions: Immunohistochemical study of the structural components of cystic formations is this is the direct way to establish the nature of the redistribution of immune cells in it, which is very important when conducting differential diagnosis in difficult and doubtful cases.

A generational comparison for unfavorable cancer of unknown primary in a single institute over 20 years

BACKGROUND

The prognosis of unfavorable cancer of unknown primary is extremely poor. This is the first report to compared the treatment results between generations of CUP and examined prognostic factors.

METHODS

This retrospective single-center cohort study enrolled 68 patients with newly diagnosed unfavorable cancer of unknown primary at Taipei Veteran General Hospital from 2017 to 2020 as study cohort and 167 patients from 2000 to 2009 as historical cohort.

RESULTS

The median overall survival was 4.3 months in the study cohort (95% CI, 2.7-6.2 months) and 4.5 months in the historical cohort (95% CI, 3.0-5.5 months; p = 0.858). Eleven patients in the study cohort received immunotherapy. The disease control rates were 45%. Multivariate analysis showed that an Eastern Cooperative Oncology Group score > 1 and a C-reactive protein level > 1 correlated with poor survival. A new prognostic stratification model was constructed by using Eastern Cooperative Oncology Group score and C-reactive protein values. The good-, intermediate-, and poor-risk groups had distinct median overall survival of 18.3, 7.0 and 1.2 months, respectively (area under the curve, 0.817; p < 0.001).

CONCLUSION

The outcome of unfavorable cancer of unknown primary has not changed much over the last 20 years. The application of a new prognostic stratification model can further stratify unfavorable cancer of unknown primary.

Intestinal metastasis from choriocarcinoma: a case series and literature review

BACKGROUND

Gestational choriocarcinoma is a rare trophoblastic tumor that spreads mainly to the lung, liver, and central nervous system. Fewer than 5% of patients present with metastasis to the gastrointestinal system and have a poor prognosis CASE PRESENTATION: We describe four cases of patients with intestinal metastasis from choriocarcinoma who visited the First Affiliated Hospital of Zhejiang University School of Medicine and the First People's Hospital of Hangzhou between April 2012 and October 2019. Four patients presented with gastrointestinal symptoms or developed gastrointestinal symptoms during treatment for choriocarcinoma. Three patients had these intestinal lesions surgically removed, and the postoperative pathology results suggested choriocarcinoma. All patients received multiple chemotherapy regimens during treatment for suboptimal human chorionic gonadotropin (hCG) levels; one patient died 22 months after a definitive diagnosis was made, and the other three patients are still undergoing regular follow-up.

CONCLUSION

Given the low incidence of intestinal metastases from choriocarcinoma, the metastatic route of intestinal metastases from choriocarcinoma remains to be elucidated, and diagnosis mainly depends on pathology findings. An effective treatment has not been determined, and surgical excision with chemotherapy is generally accepted.

Comparison of Antibodies to Detect Uroplakin in Urothelial Carcinomas

Immunohistochemistry for Uroplakin (UP) II and III is used to determine urothelial origin of carcinomas of unknown primary site and are especially valuable to differentiate urothelial carcinomas (UCs) from lung squamous cell carcinomas and prostate carcinomas. In the Nordic immunohistochemical Quality Control assessment scheme, only 45% of the participants obtained a sufficient staining result for UP. Primary antibodies (Abs) against UPII were most successful with a pass rate of 86%. No Abs against UPIII provided sufficient staining results. A comparative study was carried out on a larger cohort of tissue samples with optimized methods for the UPII mouse monoclonal antibody (mmAb) clone BC21, UPIII mmAb clone AU-1, and rabbit monoclonal antibody (rmAb) clone SP73 to evaluate the performance in a standardized way. Tissue microarrays containing 58 UCs, 111 non-UCs, and 20 normal tissues were included. The UP stains were evaluated by using H-score. Based on H-scores, samples were categorized as high-expressor (150 to 300), moderate-expressor (10 to 149), low-expressor (1 to 9), and negative (<1). The UPII mmAb clone BC21 obtained a significant higher analytical sensitivity of 69% for UCs compared with the UPIII Abs mmAb clone AU-1 and rmAb clone SP73 with 19% and 29%, respectively. No high-expressor UCs were seen for the UPIII Abs, whereas 13% of the positive UCs obtained an H-score >150 for the UPII Ab. The 2 UPIII Abs gave an analytical specificity of 100% compared with 97% for the UPII Ab being positive in 2 ovarian carcinomas and 1 cervical squamous cell carcinoma.

A Novel Multiepitope Vaccine Against Bladder Cancer Based on CTL and HTL Epitopes for Induction of Strong Immune Using Immunoinformatics Approaches

Bladder cancer is well-known cancer in two forms of muscle-invasive and non-muscle-invasive bladder cancer which is responsible for annual deaths worldwide. Common therapies methods are somewhat successful; however, these methods have the limitations such as the side effects of chemotherapy which necessitate the requirement for new preventive methods against bladder cancer. Hence, we explain a novel designed multi-epitope vaccine against bladder cancer using the immunoinformatics tool. Three well-known BLCAP, PRAM, and BAGE4 antigens were evaluated due to most repetitive CTL and HTL epitopes binding. IFNγ and IL10 inducer potential of selected epitopes were investigated, as well as liner and conformational B-cell epitopes. Human beta-defensin 3 and PADRE sequence were added to construct as adjuvants, along with EAAAK, AAY, and GGGS linkers to fuse CTL and HTL epitopes. Results showed this construct encodes a soluble, non-toxic, and non-allergic protein with 70 kDa molecular weight. Modeled 3D structure of vaccine was docked whit Toll-Like Receptors (TLR) of 7/8. Docking, molecular dynamics simulation and MMBPSA analysis confirmed stability of vaccine-TLR complexes. The immunogenicity showed this construct could elicit humoral and cellular immune responses. In silico and immunoinformatics evaluations suggest that this construct is a recombinant candidate vaccine against bladder cancer.

GATA3 positivity is associated with poor prognosis in patients with oesophageal squamous cell carcinoma

AIMS

GATA-binding protein 3 (GATA3) is a zinc finger transcription factor with diverse biological functions and is an excellent diagnostic marker for breast and urothelial carcinoma. We aimed to study GATA3 expression in oesophageal squamous cell carcinoma (SCC) and its significance with respect to histological features, clinical parameters and overall survival.

METHODS

We characterised GATA3 immunohistochemistry in 40 patients with oesophageal SCC. Electronic medical records were reviewed for clinical and follow-up information, as well as patient survival.

RESULTS

Eleven (28%) oesophageal SCC were positive for GATA3. The predominant stain patterns were patchy, with either mild or moderate intensities. Patients with GATA3-positive tumours showed significantly shorter overall survival than those with GATA3-negative tumours (p=0.023, Kaplan-Meier survival analysis with log-rank test). In the multivariate Cox proportional hazards regression model, GATA3 positivity was an independent adverse prognostic factor for overall survival (p=0.019, HR 5.671). Surgery, definitive chemotherapy and/or radiotherapy, and initial clinical stage were confirmed as independent prognostic factors.

CONCLUSION

To the best of our knowledge, this is the first study to investigate the incidence of GATA3 positivity in oesophageal SCC and showed GATA3 positivity is associated with poor prognosis in oesophageal SCC.

Pathologic Classification of Ovarian Cancer

Optimal use of human tissue for research requires an understanding of basic pathologic principles. Given that the physical assessment of tissue must occur as part of standard clinical examination, it cannot be handled directly by investigators unless they are also a part of the care team. The purpose of this chapter is to provide an overview of the clinical analytic process, from initial gross handling to histologic examination by light microscopy and the use of ancillary studies, in order to provide context for samples that are used in research and to highlight specific considerations that are relevant for obtaining appropriate tissue for experimental purposes. Given that they comprise >95% of ovarian malignancies, there is an emphasis on epithelial tumors.

Curative resection of bladder cancer with pancreas head metastasis

Bladder cancer is the 9th most frequent cancer worldwide. Its incidence is increasing. The pancreas is an infrequent site of metastasis in relation to any type of malignancy. In this study, we report our experience with a patient who has undergone a pancreaticoduodenectomy for metastatic bladder cancer. A 61-year-old male was admitted with jaundice and pancreas head mass. He underwent robot assisted-cystectomy and ileal conduit for bladder cancer 7 months ago. Initial diagnosis under the imaging study was a resectable pancreas head cancer. However, we did not rule-out a metastatic bladder cancer. He underwent a classic pancreaticoduodenectomy. Based on histologic findings and immunohistochemistry results, a pancreas tumor with 4.9-cm sized metastatic urothelial carcinoma was diagnosed. He experienced no complication. He was discharged 11 days after the surgery. Four cycles of gemcitabine and cisplatin were administered. He remained recurrence-free of tumors for 16 months. Although the benefit of pancreatectomy for patient survival has been reported for metastases from renal cell carcinoma, it is unknown for bladder cancer because of no report. We believe that curative resection for metastasis to pancreas of urothelial carcinoma might be helpful for its management.

Pediatric Small Round Blue Cell Tumors: Cytopathological Puzzle or an Intriguing Scientific Window?

BACKGROUND

Small round blue cell tumors or more commonly called small round cell tumors (SRCTs) are undifferentiated neoplasms, sharing an overlapping morphological pattern of small round blue cells. Diagnosing these tumors represents a complex challenge for cytopathologists and for general surgical pathologist alike. This stems from the fact that these tumors share not only similar morphological features, but also some immunophenotypic characteristics, thus requiring a broad panel of antibodies, which might not be included in the most basic immunohistochemistry panels, used in the routine work of most pathology laboratories. Furthermore, one should note that the diagnosis, prognosis, and/or therapeutic decision are often dependent on the knowledge of the existence of specific molecular alterations, which requires access to sophisticated molecular ancillary techniques. Cytological diagnosis of SRCT should be systematized. A thorough understanding of the morphological pattern of these tumors, the small details they entail, the background and cellular patterns, and the nuclear and cytoplasmic peculiarities, may hint to the most probable diagnosis. Minor clues, such as the presence of a fibrillar background, the presence of rosettes or a specific "salt and pepper" chromatin, are important clues toward a probable diagnosis of a neuroblastoma, or the presence of a tigroid background is a characteristic of rhabdomyosarcoma and the Ewing family tumors. However, in poorly differentiated tumors, morphology alone will not suffice, making it essential for the access to complementary diagnostic techniques in order to reach the final diagnosis. Summary and Key Messages: The cytological diagnosis and treatment of SRCTs require an experienced, well-articulated, proficient teamwork, and sophisticated complementary diagnostic techniques, only available in centers of reference.

Influencing Factors and Prognostic Value of 18F-FDG PET/CT Metabolic and Volumetric Parameters in Non-Small Cell Lung Cancer

Objective

This study aims to explore factors influencing metabolic and volumetric parameters of [¹⁸F]fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) imaging in non-small cell lung cancer (NSCLC) and the predictive value for prognosis of NSCLC.

Methods

Retrospective analysis was performed on 133 NSCLC patients who received ¹⁸F-FDG PET/CT imaging. After ¹⁸F-FDG injection at 3.7 MBq/kg, 1 h early imaging and 2 h delayed imaging were performed. The metabolic and volumetric parameters such as SUVmax, SUVpeak, SULmax, SULpeak, MTV and TLG were measured. The tumor markers including CFYRA21-1, NSE, SCC-ag and the immunohistochemical biomarkers including Ki-67, P53 and CK-7 were examined. All patients were followed up for 24 months, and the 1-year and 2-year overall survival rate (OS) were recorded.

Results

There were significant differences in metabolic and volumetric parameters (SUVmax, SUVpeak, SULmax, SULpeak and TLG) between adenocarcinoma and squamous cell carcinoma of NSCLC. SUVmax, SUVpeak, SULmax, SULpeak, MTV and TLG were correlated with tumor marker NSE and TNM stage. MTV and TLG were related to CYFRA21-1, and only MTV was associated with SCC-ag. SUVpeak and SULmax were related to P53. In addition, early SULpeak and delayed MTV were significant prognostic factors of 1-year OS, while early SUVpeak, delayed TLG and delayed MTV were predictive factors of 2-year OS in NSCLC.

Conclusion

The metabolic and volumetric parameters of ¹⁸F-FDG PET/CT were related to a variety of factors such as NSE, CFYRA21-1, SCC-ag, P53 and TNM stage, and have a predictive value in prognosis of NSCLC.

Immunocytochemistry for diagnostic cytopathology-A practical guide

Cytological specimens, which are obtained by minimally invasive methods, are an excellent source of diagnostic material. Sometimes they are the only material available for diagnosis as well as for prognostic/predictive markers. When cytomorphology is not straightforward, ancillary tests may be required for a definitive diagnosis to guide clinical management. Immunocytochemistry (ICC) is the most common and practical ancillary tool used to reach a diagnosis when cytomorphology is equivocal, to differentiate entities with overlapping morphological features, and to determine the cell lineage and the site of origin of a metastatic neoplasm. Numerous immunomarkers are available, and some are expressed in multiple neoplasms. To rule out entities within a differential diagnosis, the use of more than one marker, sometimes panels, is necessary. ICC panels for diagnostic purposes should be customised based on the clinical context and cytomorphology, and the markers should be used judiciously to preserve material for additional tests for targeted therapies in the appropriate setting. This review offers a practical guide for the use of ICC for diagnostic cytopathology, covering the most commonly encountered non-hematolymphoid diagnostic scenarios in various body sites.

A decade of change: Trends in the practice of cytopathology at a tertiary care cancer centre

OBJECTIVES

The practice of cytopathology has evolved over the past decade with a growing need for doing more with less tissue. Changes in clinical practice guidelines and evolving needs in tissue acquisition for diagnosis and treatment have affected various areas of cytopathology in different ways. In this study, we evaluated the changing trends in cytopathological practice at our institution over the past decade.

METHODS

We performed a retrospective review of our institutional database for cytopathology cases from calendar years 2009 (n = 28038) and 2019 (n = 31386) to evaluate the changing trends in practice.

RESULTS

The overall number of exfoliative cases decreased 10% over the past decade, primarily due to a 64% decrease in gynaecological Pap testing. However, the volume of serous body cavity and cerebrospinal fluids increased 125% and 44%, respectively. The overall volume of fine needle aspiration (FNA) cases increased 38% from 2009 to 2019. The number of FNA cases increased across most body sites, driven primarily by a 180% increase in endobronchial ultrasound-guided transbronchial needle aspiration cases. In contrast, breast FNA volume decreased 43%. Ancillary studies increased substantially over the past decade, including immunostains (476%) and molecular testing (250%).

CONCLUSIONS

The trends in our cytopathological practice showed an increased volume of cases, especially in non-gynaecological specimens. As expected, the number of FNA cases used for immunostains and molecular testing increased substantially, indicating an upward trend in ancillary studies in cytopathological practice.

An algorithmic approach utilizing CK7, TTF1, beta-catenin, CDX2, and SSTR2A can help differentiate between gastrointestinal and pulmonary neuroendocrine carcinomas

Primary gastrointestinal neuroendocrine carcinoma (GI-NEC) cannot be distinguished morphologically from pulmonary neuroendocrine carcinoma (P-NEC). This can present a significant diagnostic challenge in cases where site of origin cannot be readily determined. To identify immunohistochemical (IHC) markers that can be used to reliably distinguish between GI-NECs and P-NECs, we constructed 3-mm tissue microarrays, one containing 13 GI-NECs and one containing 20 P-NECs. IHC was performed on both microarrays using 21 stains: AE1/AE3, CK7, CK20, synaptophysin, chromogranin, CD56, INSM1, SSTR2A, CDX2, SATB2, TTF1, Napsin A, PR, GATA3, PAX8, ISL1, beta-catenin, AFP, SMAD4, Rb, and p53. For GI-NEC, the most strongly expressed marker was synaptophysin (mean H-score 248), while AE1/AE3 was the most strongly expressed in P-NEC (mean H-score 230), which was stronger than in GI-NEC (p = 0.011). Other markers that were stronger overall in P-NEC than in GI-NEC included CK7 (p < 0.0001) and TTF1 (p < 0.0001). Markers that were stronger overall in GI-NEC than in P-NEC included SSTR2A (p = 0.0021), SATB2 (p = 0.018), CDX2 (p = 0.019), and beta-catenin (nuclear; p = 0.029). SMAD4, Rb, and p53 showed similar rates of abnormal protein expression. Based on these results, a stepwise algorithmic approach utilizing CK7, TTF1, beta-catenin, CDX2, and SSTR2A had a 91% overall accuracy in distinguishing these GI-NEC from P-NEC. This was tested on a second cohort of 10 metastatic GI-NEC and 10 metastatic P-NEC, with an accuracy in this cohort of 85% and an overall accuracy of 89% for the 53 cases tested. Our algorithm reasonably discriminates GI-NEC from P-NEC using currently available IHC stains.

Small Bowel Adenocarcinomas Featuring Special AT-Rich Sequence-Binding Protein 2 (SATB2) Expression and a Colorectal Cancer-Like Immunophenotype: A Potential Diagnostic Pitfall

Simple Summary

Since small bowel adenocarcinoma may mimic a colorectal primary neoplasm histologically, it is pivotal to find biomarkers to discriminate these two biologically distinct neoplasms. The aim of our study was to evaluate the expression of special AT-rich sequence-binding protein 2 (SATB2), expressed in the vast majority of colorectal carcinomas, and other gastrointestinal phenotypic markers, such as cytokeratin 7, cytokeratin 20 and caudal type homeobox 2 (CDX2), in 100 small bowel adenocarcinomas. We identified 20 SATB2-positive small bowel adenocarcinomas, including nine sporadic cancers, seven celiac disease-associated cancers and four Crohn’s disease-associated small bowel adenocarcinomas. Six small bowel adenocarcinomas, including two cases associated with celiac disease and four sporadic, displayed a full colorectal carcinoma-like immunoprofile. Unlike SATB2, cytokeratin patterns stratified small bowel adenocarcinoma patient prognosis. The small bowel should be considered as one of the possible sites of origin in cancers of unknown primary, even when the neoplasm shows a colorectal carcinoma-like immunoprofile.

Abstract

Special AT-rich sequence-binding protein 2 (SATB2) is a transcription factor expressed by colonic cryptic epithelium and epithelial neoplasms of the lower gastrointestinal (GI) tract, as well as by small bowel adenocarcinomas (SBAs), though at a lower rate. Nevertheless, up to now, only small SBA series, often including a very limited number of Crohn’s disease-associated SBAs (CrD-SBAs) and celiac disease-associated SBAs (CD-SBA), have been investigated for SATB2 expression. We evaluated the expression of SATB2 and other GI phenotypic markers (cytokeratin (CK) 7 and CK20, caudal type homeobox 2 (CDX2) and alpha-methylacyl-CoA racemase (AMACR)), as well as mismatch repair (MMR) proteins, in 100 SBAs, encompassing 34 CrD-SBAs, 28 CD-SBAs and 38 sporadic cases (Spo-SBAs). Any mutual association and correlation with other clinico-pathologic features, including patient prognosis, were searched. Twenty (20%) SATB2-positive SBAs (4 CrD-SBAs, 7 CD-SBAs and 9 Spo-SBAs) were identified. The prevalence of SATB2 positivity was lower in CrD-SBA (12%) in comparison with both CD-SBAs (25%) and Spo-SBAs (24%). Interestingly, six SBAs (two CD-SBAs and four Spo-SBAs) displayed a full colorectal carcinoma (CRC)-like immunoprofile (CK7−/CK20+/CDX2+/AMACR+/SATB2+); none of them was a CrD-SBA. No association between SATB2 expression and MMR status was observed. Although SATB2-positive SBA patients showed a more favorable outcome in comparison with SATB2-negative ones, the difference did not reach statistical significance. When cancers were stratified according to CK7/CK20 expression patterns, we found that CK7−/CK20- SBAs were enriched with MMR-deficient cases (71%) and patients with CK7−/CK20− or CK7−/CK20+ SBAs had a significantly better survival rate compared to those with CK7+/CK20− or CK7+/CK20+ cancers (p = 0.002). To conclude, we identified a small (6%) subset of SBAs featuring a full CRC-like immunoprofile, representing a potential diagnostic pitfall in attempts to identify the site of origin of neoplasms of unknown primary site. In contrast with data on colorectal carcinoma, SATB2 expression is not associated with MMR status in SBAs. CK patterns influence patient survival, as CK7−/CK20− cancers show better prognosis, a behavior possibly due to the high rate of MMR-deficient SBAs within this subgroup.

Uncommon Cervical Lesions: A Review and Discussion of the Differential Diagnosis

CONTEXT.—

While the vast majority of cervical tumors consist of human papillomavirus (HPV)-related squamous cell carcinoma or adenocarcinoma, a subset of rare tumor types, frequently unrelated to HPV, does occur in this location. These tumors vary widely in prognostic and therapeutic implications, and accurate recognition is crucial to providing appropriate treatment. Some are benign or portend a favorable prognosis (adenoid basal carcinoma, ectopic prostate tissue), while others are frankly malignant lesions with a less favorable prognosis (adenoid cystic carcinoma, HPV-negative endocervical adenocarcinoma, mesonephric adenocarcinoma, clear cell carcinoma, small cell carcinoma, and adenosquamous carcinoma).

OBJECTIVE.—

To review the morphologic features of uncommon cervical lesions, the utility of immunohistochemistry for distinction between these entities, and the clinical and prognostic implications of accurate diagnosis.

DATA SOURCES.—

University of Michigan cases and review of the pertinent literature regarding the entities described.

CONCLUSIONS.—

Key morphologic and immunohistochemical features detailed herein will allow for the accurate distinction between these uncommon cervical lesions. Morphology is most useful in discriminating between the entities, as there is frequent immunohistochemical overlap between them; however, in rare instances immunohistochemistry can be useful in resolving the diagnosis.

Incidence and significance of GATA3 positivity in gallbladder adenocarcinoma

GATA3 immunostaining is a sensitive marker for mammary and urothelial carcinomas. It is routinely used in surgical pathology during workup of carcinomas of unknown origin. To the best of our knowledge, this is the first focused study of GATA3 expression in gallbladder adenocarcinomas. In this study, we evaluated GATA3 expression in 38 gallbladder adenocarcinomas. Eight of 38 (21%) gallbladder adenocarcinomas were positive for GATA3. The expression of GATA3 tended to be moderate to strong when present. It was patchy (<50% positivity) in 4 cases, characterized by discrete clusters or groups of malignant cells with areas of intervening negative tumor cells, whereas it was diffuse (>50% positivity) in the other 4 cases. GATA3 expression did not show any significant correlation with clinicopathologic features such as sex, histologic grade, perineural invasion, vascular invasion, pathologic stage, or distance metastasis. The results of our study show that a subset of gallbladder adenocarcinomas (21%) can be GATA3 positive. Awareness of this phenomenon is important while working up GATA3-positive carcinomas immunohistochemically.