Expression Of Neuroendocrine Markers Research Articles

Extraskeletal Ewing Sarcoma of the Gastrointestinal and Hepatobiliary Tract: Deceptive Immunophenotype Commonly Leads to Misdiagnosis.

Ewing sarcoma (ES) is an uncommon mesenchymal neoplasm that typically develops as a bone mass, although up to 30% arise in extraskeletal sites. ES of the gastrointestinal (GI) and hepatobiliary tract is rare and may be misdiagnosed as other, more common neoplasms that occur in these sites. However, the correct classification of extraskeletal ES is important for timely clinical management and prognostication. We reviewed our experience of ES in the GI and hepatobiliary tract in order to further highlight the clinicopathologic features of these neoplasms and document the potential for misdiagnosis in this setting. The archives and consultation files of 6 academic institutions were retrospectively queried for cases of ES occurring in the GI and hepatobiliary tract. The histologic slides and ancillary studies were reviewed and clinical data were retrieved for each case through the electronic medical records, when available. Twenty-three patients with ES in the GI and/or hepatobiliary tract were identified from 2000 to 2022. Of these, 11 were women and 12 were men with a median age of 38 years (range, 2 to 64). Tumor locations included the pancreas (n=5), liver (n=2), stomach (n=3), colorectum (n=3), and small intestine (n=5), as well as tumors involving multiple organs, pelvis and retroperitoneum (n=5). Tumor size varied between 2cm and 18cm. Twenty were primary and 3 were metastases. Of the 23 cases, only 17% were initially diagnosed as ES. The most common misdiagnoses involved various forms of neuroendocrine neoplasia due to expression of synaptophysin and other neuroendocrine markers (22%). A wide variety of diagnoses including GI stromal tumor was considered due to aberrant CD117 expression (4%). The diagnosis of ES was ultimately confirmed by detection of the EWSR1 rearrangement in 22 cases. The remaining case was diagnosed using traditional immunohistochemistry. Follow-up information was available in 20 cases, with follow-up time varying between 2 and 256 months. Six patients with follow-up died of disease between 6 and 60 months following initial presentation. Our data indicate ES in the GI and hepatobiliary tract is commonly misdiagnosed leading to a delay in therapy. In light of the attendant therapeutic and prognostic implications, ES should be considered in the differential diagnosis of any GI or hepatobiliary tumor with epithelioid and/or small round cell morphology.

Mutational analysis of pulmonary large cell neuroendocrine carcinoma: APC gene mutations identify a good prognostic factor

Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a highly aggressive neoplasm with biological heterogeneity. Mutations in multiple genes have been identified in LCNEC. However, associations between gene alterations, histopathological characteristics, and prognosis remain ambiguous. Here, we investigated the clinicopathologic, immunohistochemical, and genomic characteristics of19 LCNEC and 9 atypical carcinoid (AC). We revealed high mutation frequencies of TP53 (89.5 %), RB1 (42.1 %), APC (31.6 %), and MCL1 (31.6 %) in LCNEC, while genetic alterations were rarely found in AC. APC alterations mainly occurred to the exon 16 and were only identified in LCNEC with wildtype RB1. The 19 LCNEC were further subgrouped into APC wild-type (LCNEC-APCMT, 6/19) and APC-mutated (LCNEC-APCWT, 13/19) subgroups. In comparison with LCNEC-APCWT, LCNEC-APCMT displayed lower TMB (median: 12.64 vs 4.20, P = 0.045), and relatively mild cytologic atypia. In addition, LCNEC-APCMT distinguished itself from AC and LCNEC-APCWT by obviously downregulated expression of neuroendocrine markers (CD56 and Syn, P < 0.01) and significantly altered expression of genes downstream of APC (β-catenin migrating into the cytoplasm and nucleus, P < 0.001; c-Myc upregulating, P = 0.005). The OS of LCNEC-APCMT was numerically intermediate between AC and LCNEC-APCWT. We first proposed that APC alterations were common in LCNEC with wildtype RB1 and that LCNEC-APCMT was associated with lower TMB and better OS in comparison with LCNEC-APCWT.

POU2F3-expressing intraepithelial small-cell carcinoma with mixed small-cell carcinoma and conventional-type urothelial carcinoma of the urinary bladder.

Based on lineage-specific transcription factors, small-cell neuroendocrine carcinoma (SmCC) of the urinary bladder has recently been subtyped into three molecular subtypes: ASCL1, NEUROD1 and POU2F3. The latter is a master transcriptional regulator of tuft cells (TCs) which are rare solitary cells found in various mucosal epithelia such as the gastrointestinal tract, but which have not been reported in the bladder. The POU2F3 subtype shows low or absent neuroendocrine marker expression. A case of mixed SmCC and conventional-type urothelial carcinoma (CUC) of the urinary bladder with POU2F3-expressing intraepithelial small-cell carcinoma in keeping with a tuft cell phenotype, arising in association with intestinal metaplasia (IM) is described. The presence of POU2F3-expressing cells in normal urothelium, cystitis cystica glandularis and IM of the urinary bladder is demonstrated in separate cases of cystitis cystica glandularis with IM. Also, POU2F3 expression is identified in a subset of bladder SmCC.

Abstract 3394: Participation of molecular iodine and PPARG in prostate cancer progression and neuroendocrine differentiation

Abstract Introduction: Advanced prostate cancer (PCa) therapy is based on androgen deprivation; however, cancerous cells develop resistance, and can develop a highly aggressive neuroendocrine (NE) phenotype. Molecular iodine (I2) has antitumoral effects in breast cancer models, in which PPARG receptors represent the main mechanism of action described. In PCa though, PPARG is considered pro-tumoral and I2 effects have not been fully studied. Hence, the aim of this study was to analyze I2 individual and combined effects with androgen deprivation by using both androgen dependent (AD) and independent (AI), in vitro and in vivo PCa models. Methods: In vitro. I2 effects in cell viability and invasion were analyzed in AD (LNCaP) and AI (DU145, PC3) PCa cells. LNCaP cells were also treated with androgen receptor (AR) antagonists. PPARG participation in I2 effects was assessed with GW9962 (antagonist) and rosiglitazone (agonist). NE phenotype was induced in LNCaP by prolonged culture under androgen-depleted conditions and was assessed by measuring the growth and length of neurite-like projections. RT-qPCR was employed to assess the expression of NE markers (SYP, ENO2), and lipogenic genes (FASN, SREBF1). In vivo. Eighteen weeks-old TRAMP mice were subjected to sham surgery or castration, and were provided or not with I2 (0.025%, drinking water) for four weeks. Prostates were subjected to histopathological analysis (H&amp;E and Masson's trichrome) and IHC (AR, SYP, PPARG). Scoring systems were used to grade the severity of high proliferative intraepithelial lesions (HPIN), and desmoplasia. Results: I2 decreased the cell viability and invasion capacity of all PCa cells tested, and when supplied with AR antagonists further enhanced their antiproliferative effects in LNCaP cells. I2 failed to induce the expression of PPARG target genes, and GW9662 did not prevent I2-induced decrease in cell viability. Like androgen deprivation, I2 also caused NE-like morphology in LNCaP cells, but unlike androgen deprived LNCaP cells, I2 treated cells had decreased expression of NE markers. In TRAMP mice, I2 increased the presence of HPIN, reduced nuclear AR protein detection, and had no effect on PPARG. As expected, castration reduced HPIN, caused epithelial atrophy and desmoplasia; decreased total AR levels and PPARG nuclear levels. However, the number of NE (SYP-positive) cells did not change. The addition of I2 to castration did not modify the score of epithelial lesions but increased the desmoplasia and the presence of NE cells. Conclusions: I2 exhibited in vitro antineoplastic effects over epithelial cells, however, these effects did not translate into the in vivo model. PPARG did not seem to mediate I2 effects. Overall, our data suggest that tumoral microenvironment may interfere with I2 epithelial-specific antitumoral effects. Funding: PAPIIT-UNAM (IN217223, IN202322) and CONAHCYT (774791). Citation Format: Carlos Montes de Oca, Lourdes Álvarez, Carmen Aceves, Brenda Anguiano. Participation of molecular iodine and PPARG in prostate cancer progression and neuroendocrine differentiation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3394.

Abstract 6574: UCHL1 is a molecular indicator and a therapeutic target for neuroendocrine carcinomas

Abstract Neuroendocrine carcinomas, such as neuroendocrine prostate cancer (NEPC), small cell lung cancer (SCLC), and neuroblastoma, share common histological features, including expression of neuroendocrine markers, rapid relapse after treatment, and poor prognosis. Due to the poor clinical outcome of patients with neuroendocrine carcinomas, there is a critical need to identify new drivers, therapeutic targets, and effective therapeutic strategies for these malignancies. Ubiquitin carboxy-terminal hydrolase L1 (UCHL1) is a protease that has a dual function in regulating protein stability. We demonstrated that UCHL1 is significantly elevated in tissues from patients with NEPC, SCLC, and neuroblastoma. Loss of UCHL1 decreases tumor growth and inhibits metastasis of these malignancies. UCHL1 maintains neuroendocrine differentiation and promotes cancer progression by regulating nucleoporin, POM121, and p53. UCHL1 binds, deubiquitinates, and stabilizes POM121 to regulate POM121-associated nuclear transport of key transcriptional factors, E2F1 and c-MYC. Conversely, UCHL1 binds p53 and promotes p53 degradation. Importantly, treatment with UCHL1 inhibitors significantly reduces tumor growth and metastasis of neuroendocrine carcinomas. The combination of UCHL1 inhibitors with cisplatin, the standard of care used for neuroendocrine carcinomas, halts tumor growth in pre-clinical settings. Our study reveals new mechanisms of UCHL1 function in neuroendocrine carcinomas tumorigenesis and identifies UCHL1 as a therapeutic target and potential molecular indicator for diagnosis and monitoring treatment responses in neuroendocrine carcinomas. Citation Format: Shiqin Liu, Timothy Chai, Fernando Marques, Qingqing Yin, En-Chi Hsu, Michelle Shen, Angus Toland, Abel Bermudez, Alifiani B. Hartono, Christopher F. Massey, Chung S. Lee, Liwei Zheng, Maya Baron, Caden J. Denning, Merve Aslan, Holly Nguyen, Rosalie Nolley, Amina Zoubeidi, Millie Das, Christian Kunder, Brooke Howitt, H Tom Soh, Irving L. Weissman, Michael A. Liss, Arnold I. Chin, James D. Brooks, Eva Corey, Sharon Pitteri, Jiaoti Huang, Tanya Ivanova Stoyanova. UCHL1 is a molecular indicator and a therapeutic target for neuroendocrine carcinomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6574.

Lung NETs and GEPNETs: One Cancer with Different Origins or Two Distinct Cancers?

Lung neuroendocrine tumors (LNETs) and gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are two distinct types of neuroendocrine tumors (NETs) that have traditionally been treated as a single entity despite originating from different sources. Although they share certain phenotypic characteristics and the expression of neuroendocrine markers, they exhibit differences in their microenvironment, molecular mutations, and responses to various therapeutic regimens. Recent research has explored the genetic alterations in these tumors, revealing dissimilarities in the frequently mutated genes, the role of EGFR in carcinogenesis, the presence of transcription factors, and the immunogenicity of the tumor and its microenvironment. Spread Through Air Spaces (STAS), a phenomenon unique to lung carcinomas, appears to play a crucial role in LNET prognosis. These distinctions are also evident in the cascade response of lung and GI tract neuroendocrine tumors to somatostatin analogs, Peptide Receptor Radionuclide Therapy (PRRT), chemotherapy, and immunotherapy. Identifying similarities and differences between the two groups may improve our understanding of the underlying mechanisms and facilitate the development of more effective treatment strategies.

Neuroendocrine and squamous cell phenotypes of NUT carcinoma are potential diagnostic pitfalls that discriminating it from mimickers, such as small cell and squamous cell carcinoma

IntroductionNUT carcinoma is a rare cancer associated with a poor prognosis. Because of its rarity, its diagnosis is challenging and is usually made by excluding other diagnoses. Immunohistochemical analysis is a reliable technique that contributes to a correct diagnosis, but overestimating the expression of neuroendocrine (NE) markers may result in an incorrect diagnosis. In this study, we established the immunohistochemical phenotypes of NUT carcinoma compared with tumors that mimic its phenotype to identify potential diagnostic pitfalls.MethodsEight cases of NUT carcinoma were examined along with eight basaloid squamous cell carcinomas and thirteen cases of small cell carcinoma using an immunohistochemical panel consisting of various antibodies.ResultsOf the eight NUT carcinomas, three patients had a smoking history. All the cases examined for INSM1 were positive (6/6, 100%), although the staining was somewhat weak. Among the NE markers, synaptophysin was variably positive in two NUT carcinomas (2/6, 33%); however, all cases were negative for ASCL1, chromogranin A, and CD56. Moreover, the squamous cell markers, p40 and CK5/6, were weakly expressed in 4/6 (67%) and 3/6 (50%) of the NUT carcinomas, respectively.ConclusionsFor tumors with an ambiguous morphology, applying the neuroendocrine phenotype of NUT carcinoma may be misleading; particularly, when distinguishing it from small-cell carcinoma. Similarly, null or weak expression of squamous cell markers may be observed in NUT carcinoma, but this differs from squamous cell carcinoma, which consistently demonstrates strong positivity for squamous cell markers.

Relationship between patterns of immunohistochemical conventional neuroendocrine markers and efficacy of immune check point inhibitors in patients with extensive disease small cell lung cancer.

Which patients benefit from the addition of immune checkpoint inhibitors (ICIs) to chemotherapy for small cell lung cancer (SCLC) remains unclear. There have been few reports on the efficacy of ICIs based on conventional immunohistochemical neuroendocrine (NE) markers (synaptophysin, chromogranin A, and neural cell adhesion molecule [NCAM]). In the present study, we aimed to analyze the relationship between the expression of immunohistochemical NE markers and the efficacy of ICIs in patients with extensive disease (ED)-SCLC, to assess whether conventional NE markers are predictive of ICIs. Patients with untreated ED-SCLC who received first-line therapy at the Shizuoka Cancer Center between November 2002 and July 2021 were retrospectively reviewed. We evaluated the efficacy of first-line chemotherapy according to the expression status of each immunohistochemical NE marker in patients treated with ICI plus chemotherapy (ICI-chemo group) and with chemotherapy alone (chemo group). A total of 227 patients were included in the ICI-chemo and chemo groups, respectively. The progression-free survival (PFS) tended to be better in patients in the ICI-chemo group than those treated with chemotherapy alone in patients with NE marker-positive SCLC. In particular, it was statistically significant in patients with chromogranin A-positive SCLC (p = 0.036). In patients with NE marker-negative SCLC, no significant differences were observed in PFS between the two groups. There were no significant differences in overall survival (OS), regardless of the expression of any conventional NE marker. Our study suggests that the efficacy of ICIs in addition to chemotherapy may be poor in patients with NE marker-negative SCLC.

Spatial profiling reveals tissue-specific neuro-immune interactions in gastroenteropancreatic neuroendocrine tumors.

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are heterogeneous malignancies that arise from complex cellular interactions within the tissue microenvironment. Here, we sought to decipher tumor-derived signals from the surrounding microenvironment by applying digital spatial profiling (DSP) to hormone-secreting and non-functional GEP-NETs. By combining this approach with in vitro studies of human-derived organoids, we demonstrated the convergence of cell autonomous immune and pro-inflammatory proteins that suggests their role in neuroendocrine differentiation and tumorigenesis. DSP was used to evaluate the expression of 40 neural- and immune-related proteins in surgically resected duodenal and pancreatic NETs (n = 20) primarily consisting of gastrinomas (18/20). A total of 279 regions of interest were examined between tumors, adjacent normal and abnormal-appearing epithelium, and the surrounding stroma. The results were stratified by tissue type and multiple endocrine neoplasia I (MEN1) status, whereas protein expression was validated by immunohistochemistry (IHC). A tumor immune cell autonomous inflammatory signature was further evaluated by IHC and RNAscope, while functional pro-inflammatory signaling was confirmed using patient-derived duodenal organoids. Gastrin-secreting and non-functional pancreatic NETs showed a higher abundance of immune cell markers and immune infiltrate compared with duodenal gastrinomas. Compared with non-MEN1 tumors, MEN1 gastrinomas and preneoplastic lesions showed strong immune exclusion and upregulated expression of neuropathological proteins. Despite a paucity of immune cells, duodenal gastrinomas expressed the pro-inflammatory and pro-neural factor IL-17B. Treatment of human duodenal organoids with IL-17B activated NF-κB and STAT3 signaling and induced the expression of neuroendocrine markers. In conclusion, multiplexed spatial protein analysis identified tissue-specific neuro-immune signatures in GEP-NETs. Duodenal gastrinomas are characterized by an immunologically cold microenvironment that permits cellular reprogramming and neoplastic transformation of the preneoplastic epithelium. Moreover, duodenal gastrinomas cell autonomously express immune and pro-inflammatory factors, including tumor-derived IL-17B, that stimulate the neuroendocrine phenotype. © 2024 The Pathological Society of Great Britain and Ireland.

Neuroendocrine Breast Tumors: Could Multigene Assays Help in Guiding Treatment Decisions? Case Presentation.

Breast cancer remains the most prevalent type of cancer among women worldwide, and it remains the primary cause of cancer-related deaths in this demographic. Neuroendocrine breast cancer (NBC), an uncommon subtype comprising less than 1% of cases, typically occurs in older women and displays as a slow-growing, low-grade condition. NBC exhibits distinct histological patterns and immunohistochemical markers. Given the limited data on NBC, assays are required that will provide information on molecular profiling and assist in clinical decision making. The aim of the study was to investigate whether a modern Multigene Assay (MGA) could assist on treatment planning of NBC patients. A cohort of four patients was analyzed using a MGA. The presented cases featured young, pre-menopausal women with clear NBC, lacking family history. All were lymph node-negative, with robust expression of neuroendocrine markers. Despite high hormone receptor expression, all tumors were poorly differentiated with elevated Ki67 levels. Oncotype DX analysis indicated a need for chemotherapy in three cases and not in one. This underscores the heterogeneity within NBC, emphasizing the importance of personalized treatment decisions. While NBC is rare and lacks extensive studies, the use of multigene assays like Oncotype DX may play a pivotal role in treatment planning, especially in cases with varying histological parameters.

Clonal Origin and Lineage Ambiguity in Mixed Neuroendocrine Carcinoma of the Uterine Cervix

Small cell neuroendocrine carcinoma of the cervix (SCNEC/cervix) is a rare disease characterized by a high incidence of mixed tumors with other types of cancer. The mechanism underlying this mixed phenotype is not well understood. In this study, a panel of organoid lines from patients with SCNEC/cervix was established and focused on one line, which retained a mixed tumor phenotype, both in vitro and in vivo. Histologically, both organoids and xenograft tumors showed distinct differentiation into either SCNEC or adenocarcinoma in some regions and ambiguous differentiation in others. By tracking single cells, the existence of cells with bipotential differentiation towards SCNEC and adenocarcinomas was revealed. Single-cell transcriptional analysis identified three distinct clusters: SCNEC-like, adenocarcinoma-like, and a cluster lacking specific differentiation markers. The expression of neuroendocrine markers was enriched in the SCNEC-like cluster but not exclusively. Human papillomavirus 18 E6 was enriched in the SCNEC-like cluster, which showed higher proliferation and lower levels of the p53 pathway. After treatment with anticancer drugs, the expression of adenocarcinoma markers increased, whereas that of SCNEC decreased. Using a reporter system for KRT19 expression, changes in the differentiation of each cell were revealed to be associated with the shift in differentiation induced by drug treatment. These data suggest that mixed SCNEC/cervical tumors have a clonal origin and are characterized by an ambiguous and flexible differentiation state.

Targeting the αVβ3/NgR2 pathway in neuroendocrine prostate cancer

Highly aggressive, metastatic, neuroendocrine prostate cancer, which typically develops from prostate cancer cells acquiring resistance to androgen deprivation therapy, is associated with limited treatment options and hence poor prognosis. We have previously demonstrated that the αVβ3 integrin is over-expressed in neuroendocrine prostate cancer. We now show that LM609, a monoclonal antibody that specifically targets the human αVβ3 integrin, hinders the growth of neuroendocrine prostate cancer patient-derived xenografts in vivo. Our group has recently identified a novel αVβ3 integrin binding partner, NgR2, responsible for regulating the expression of neuroendocrine markers and for inducing neuroendocrine differentiation in prostate cancer cells. Through in vitro functional assays, we here demonstrate that NgR2 is crucial in promoting cell adhesion to αVβ3 ligands. Moreover, we describe for the first time co-fractionation of αVβ3 integrin and NgR2 in small extracellular vesicles derived from metastatic prostate cancer patients’ plasma. These prostate cancer patient-derived small extracellular vesicles have a functional impact on human monocytes, increasing their adhesion to fibronectin. The monocytes incubated with small extracellular vesicles do not show an associated change in conventional polarization marker expression and appear to be in an early stage that may be defined as “adhesion competent”. Overall, these findings allow us to better understand integrin-directed signaling and cell-cell communication during cancer progression. Furthermore, our results pave the way for new diagnostic and therapeutic perspectives for patients affected by neuroendocrine prostate cancer.

Expression of neuroendocrine markers in sinonasal rhabdomyosarcoma of an adult patient: A potential diagnostic pitfall.

Expression of neuroendocrine markers in sinonasal rhabdomyosarcoma of an adult patient: A potential diagnostic pitfall.

POU2F3-Expressing Small Cell Lung Carcinoma and Large Cell Neuroendocrine Carcinoma Show Morphologic and Phenotypic Overlap.

Considering the differences in protein expression in small cell lung carcinoma (SCLC) by molecular classification, it is likely that there are differences in morphology, but the relationship between molecular classification and morphology has not been examined. Furthermore, there are limited reports concerning this molecular classification for large cell neuroendocrine carcinoma (LCNEC) and SCLC simultaneously. Therefore, we investigated the relationship between immunohistochemistry-based molecular classification and morphology, protein expression, and clinical features of 146 consecutive resection specimens of pulmonary neuroendocrine carcinoma (NEC), focusing mainly on POU2F3, the master transcription factor involved in tuft cell generation. POU2F3-dominant SCLC (n=24) and LCNEC (n=14) showed overlap in cytomorphology, while non-POU2F3-dominant SCLC (n=71) and LCNEC (n=37) showed distinct differences in cytomorphology. In addition, POU2F3-dominant NEC exhibited significantly more abundant tumor stroma, more prominent nest formation, more frequent bronchial intraepithelial involvement, and less frequent background fibrosis than non-POU2F3-dominant NEC. Immunohistochemically, POU2F3-dominant SCLC and LCNEC were characterized by lower expression of TTF-1, CEA, and neuroendocrine markers and higher expression of bcl-2, c-Myc, and c-kit. Clinically, POU2F3-dominant NEC had a significantly better prognosis than non-POU2F3-dominant NEC for recurrence-free survival. POU2F3-dominant NEC had a higher smoking index than non-POU2F3-dominant NEC. POU2F3-dominant NEC forms a unique population, exhibiting intermediate morphologic features between SCLC and LCNEC, with distinct protein expression as tuft cell-like carcinoma. Recognition of this unique subtype may provide clues for solving the long-standing issues of NEC and appropriate therapeutic stratification. It is important to accurately identify POU2F3-expressing carcinomas by immunohistochemistry and to analyze their clinicopathological features.

On a Complex Biphasic Neoplasm Involving the Ovary and Omentum Expressing Neuroendocrine Markers, HBME1 and TTF1: A Case Report and the Literature Review

A Case of Malignant Mixed Ovarian Tumor (OMMMT) with synchronous mesenteric localization presenting heterologous expression of neuroendocrine markers, mesothelin and TTFI is studied. The peculiarity of this case is that of presenting immunophenotypic characters not yet reported in the literature in OMMMT.

Ovarian Endometrioid Adenocarcinomas With Infiltrative "Adenofibroma-like" Morphology and Aberrant ß-catenin Expression: Tumors That Coexpress CDX2 and LEF1 With Frequent Neuroendocrine Marker Expression, Diminished/Lost PAX8 and Possible Association With Endometrioid Type II Stem Cell Outgrowths in the Fallopian Tube.

Ovarian Endometrioid Adenocarcinomas With Infiltrative "Adenofibroma-like" Morphology and Aberrant ß-catenin Expression: Tumors That Coexpress CDX2 and LEF1 With Frequent Neuroendocrine Marker Expression, Diminished/Lost PAX8 and Possible Association With Endometrioid Type II Stem Cell Outgrowths in the Fallopian Tube.

Equivalent Survival between Gastric Large-Cell Neuroendocrine Carcinoma and Gastric Small-Cell Neuroendocrine Carcinoma.

According to the 2019 World Health Organization (WHO) classification of gastric neuroendocrine neoplasms, gastric neuroendocrine carcinoma (GNEC) can be further divided into gastric large-cell neuroendocrine carcinoma (GLNEC) and gastric small-cell neuroendocrine carcinoma (GSNEC). Whether the prognoses of the two types have a discrepancy has long been disputed. We collected patients diagnosed with GLNEC or GSNEC in the National Cancer Center of China between January 2000 and December 2020. The characteristics and survival outcomes were compared between the two groups. We further verified our conclusion using the SEER dataset. A total of 114 GNEC patients, including 82 patients with GLNEC and 32 patients with GSNEC, have completed treatment in our hospital. Clinicopathologic differences were not observed between patients with GSNEC and GLNEC concerning the sex, age, body mass index, Charlson Comorbidity Index, tumor location, tumor size, stage, treatment received, the expression of neuroendocrine markers (CD56, Chromogranin A, synaptophysin), and score on the Ki-67 index. The 1-year, 3-year, and 5-year overall survival rates of GLNEC and GSNEC were 89.0%, 60.5%, and 52.4%, and 93.8%, 56.3%, and 52.7%, which showed no statistically significant differences. This result was confirmed further by using the SEER dataset after the inverse probability of treatment weighting. Although with different cell morphology, the comparison of prognosis between the GLNEC and GSNEC has no significant statistical difference.

Mimickers of neuroendocrine tumors on endoscopic ultrasound-guided fine-needle aspirate material: Need for caution.

Cytologic diagnosis of neuroendocrine tumors can be straightforward on cytologic preparations, given the classical neuroendocrine morphology and expression of neuroendocrine markers confirmed by immunohistochemistry. However, overreliance on neuroendocrine markers can lead to misdiagnosis even if individual cell features suggest a neuroendocrine tumor. We present three unusual cases, two of which were initially diagnosed as neuroendocrine tumors and the third one carried preliminary diagnosis of neuroendocrine tumor on endoscopic ultrasound-guided fine-needle aspirates. These cases subsequently turned out to be cholangioblastic cholangiocarcinoma, metastatic melanoma, and gastric glomus tumor, respectively. We suggest approaches that could have pointed us towards the correct diagnosis at the outset and discuss potential pitfalls.

Spectrum of neuroendocrine neoplasms of GIT – a histomorphological study in a tertiary care centre

Background. Neuroendocrine neoplasms are diverse in terms of sites of origin, functional status, and degrees of aggressiveness. Since neuroendocrine cells are ubiquitous in the human body, these neoplasms can arise in different organs, with gastrointestinal tract being most frequently involved. The past few years have seen a surge in the diagnosis of these neoplasms, which were earlier considered to be rare. Their nomenclature, classification, and diagnostic criteria are revamped frequently, as new knowledge emerges. Aim. To study the histopathological spectrum of neuroendocrine neoplasms of gastrointestinal tract and assess the immunohistochemical expression of neuroendocrine markers in them. Material and methods. Ours is a descriptive study of the distribution and pathologic characteristics of gastrointestinal neuroendocrine neoplasms in a tertiary care hospital in Kerala, over a three year period. Neoplasms were categorised based on 2019 updated WHO classification. Results. Among the 59 cases, we observed a male predominance. (Male to female ratio - 1.8:1). Most patients were in 6th and 7th decades of life. Duodenum was most frequently involved followed by rectum and appendix. NET G2 and G1 constituted the predominant histologic grades (47% and 24% respectively). NEC and MiNEN were infrequent. All cases were positive for synaptophysin, with variable positivity for chromogranin. Ki67 helped establish the histologic grade. We also came across a rare case of neuroendocrine tumor with coexisting mucinous neoplasm in appendix. Conclusions. With evolving knowledge and advanced imaging modalities, the incidence of these neoplasms is increasing with time. Histopathology is the mainstay of diagnosis and plays a decisive role in influencing management protocols and prognosis.

Identification of Lineage-specific Transcriptional Factor–defined Molecular Subtypes in Small Cell Bladder Cancer

Small cell/neuroendocrine bladder cancers (SCBCs) are rare and highly aggressive tumors that are associated with poor clinical outcomes. We discovered that lineage-specific transcription factors (ASCL1, NEUROD1, and POU2F3) defined three SCBC molecular subtypes that resemble well-characterized subtypes in small cell lung cancer. The subtypes expressed various levels of neuroendocrine (NE) markers and distinct downstream transcriptional targets. Specifically, the ASCL1 and NEUROD1 subtypes had high NE marker expression and were enriched with different downstream regulators of the NE phenotype (FOXA2 and HES6, respectively). ASCL1 was also associated with the expression of delta‐like ligands that control oncogenic Notch signaling. POU2F3, a master regulator of the NE low subtype, targeted TRPM5, SOX9, and CHAT. We also observed an inverse association between NE marker expression and immune signatures associated with sensitivity to immune checkpoint blockade, and the ASCL1 subtype had distinct targets for clinically available antibody-drug conjugates. These findings provide new insight into molecular heterogeneity in SCBCs with implications for the development of new treatment regimens. Patient summaryWe investigated the levels of different proteins in a specific type of bladder cancer (small cell/neuroendocrine; SCBC). We could identify three distinct subtypes of SCBC with similarity to small cell/neuroendocrine cancers in other tissues. The results may help in identifying new treatment approaches for this type of bladder cancer.