Search

A 37-year-old male with long-standing and extensive ulcerative pancolitis developed a rapidly lethal poorly differentiated neuroendocrine carcinoma (NEC) in the sigmoid colon. Prior biopsies obtained from multiple sites of the colon during endoscopic surveillance showed minimal inflammatory changes and no sign of dysplasia. Patients with inflammatory bowel disease (IBD) are at increased risk of colorectal malignancies, and adenocarcinoma is the most common type of colorectal neoplasm associated with ulcerative colitis and Crohn's disease, but other types of epithelial and nonepithelial tumors have also been described in IBD. NECs arising in the setting of ulcerative colitis are very rare and are reported as anecdotic findings. We describe the clinicopathological features of an IBD-related NEC and review the previously reported cases. [ABSTRACT FROM AUTHOR]

Background/Aims: Gastroenteropancreatic (GEP) neuroendocrine carcinomas (NECs) are defined as neuroendocrine neoplasms (NENs) with a Ki-67 index >20% according to the 2010 WHO classification. Some reports suggest that this category is heterogeneous. We retrospectively studied a series of 136 patients affected by grade 3 GEP-NECs with the aim to clarify the prognostic role of tumor morphological differentiation, proliferation, defect in mismatch repair proteins (MMRd), CD117 expression, and site of origin. The primary endpoint was the correlation between these parameters and the overall survival (OS). Methods: Univariate and multivariable Cox proportional hazards regression analyses were used to assess the prognostic significance of various clinical and histopathologic features. Results: With a median followup of 81 months, the median OS was 12.9 months. At multivariate analysis, morphological differentiation, Ki-67 index, MMRd, stage, and CD117 expression were independent prognostic markers in NECs. Three different prognostic categories of NECs were identified according to the degree of morphologic differentiation (well vs. poorly differentiated) and Ki-67 index (<55% vs. = 55%). On this basis, median OS was 43.6 months in well-differentiated neoplasms with a Ki- 67 index 20-55% (named type A), 24.5 months in poorly differentiated neoplasms with a Ki-67 index 20-55% (type B), and 5.3 months (p < 0.0001) in poorly differentiated neoplasms with a Ki-67 index = 55% (type C). Conclusions: The present study suggests that GEP-NECs represent a heterogeneous group of neoplasms which can be better classified in different prognostic categories using both tumor morphology and Ki-67 index. [ABSTRACT FROM AUTHOR]

Background: Mixed neuroendocrine/nonneuroendocrine carcinomas are heterogeneous tumors with poorly defined diagnostic and clinical features and without pathological or molecular markers of prognosis or markers predicting their response to therapy. We aimed at analyzing the pathological features and the expression of genes involved in DNA repair or synthesis in a cohort of patients with mixed carcinomas from different sites as compared to the patients' outcome. Methods: Relative cDNA quantification of ribonucleotide reductase, large subunit 1, excision repair cross-complementation group 1, thymidylate synthase and topoisomerase IIa genes was tested using real-time PCR on microdissected neuroendocrine and nonneuroendocrine tumor components of 42 mixed cases (from the lung as well as the gastrointestinal and genitourinary tracts) and on 45 control cases of pure neuroendocrine and nonneuroendocrine carcinomas. Results: The expression levels of all genes were stable comparing nonneuroendocrine and neuroendocrine components of mixed cases (except for topoisomerase IIa in lung samples) but significantly different as compared to control nonneuroendocrine and neuroendocrine tumors. In the multivariate analysis including all clinical and pathological parameters and gene expression levels available, a predominant nonneuroendocrine component, the administration of additional therapy other than surgery and a high thymidylate synthase expression in nonneuroendocrine tumor tissue were significantly associated with a lower risk of a patient's death. Conclusions: Our data show that mixed neuroendocrine/nonneuroendocrine carcinomas are different at the molecular level from their pure neuroendocrine and nonneuroendocrine counterparts, and detailed analyses of their clinical, pathological and molecular features may improve the clinical strategies for the treatment of these rare and underestimated tumors. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Neuroendocrine carcinomas show overlapping morphological and immunohistochemical features independently of their site of origin, which makes identification of the primary location problematic when they are diagnosed as metastases of unknown origin. Neuroendocrine carcinomas are easily morphologically differentiated from neuroendocrine tumors in surgical material, although this distinction can be difficult when using small biopsy specimens. The diagnostic usefulness of different transcription factors as site-specific markers or as discriminating markers between neuroendocrine carcinomas and neuroendocrine tumors has been previously studied with sometimes contradictory results. In this respect, the role of achaete-scute homolog 1 has been poorly investigated, although some recent findings demonstrate its expression in neuroendocrine carcinomas. Using immunohistochemistry and quantitative real-time polymerase chain reaction, we investigated the expression of achaete-scute homolog 1 in 335 neuroendocrine neoplasms (194 neuroendocrine carcinomas and 141 neuroendocrine tumors) of different sites, to check its possible utility as diagnostic marker. High concordance between immunohistochemical and molecular findings was found. Achaete-scute homolog 1 expression was identified in 82% of lung neuroendocrine carcinomas and 70% of extrapulmonary neuroendocrine carcinomas. Achaete-scute homolog 1 was not detected in any gastroenteropancreatic neuroendocrine tumor and was found in only a minority of lung carcinoids. The diagnostic sensitivity and specificity of achaete-scute homolog 1 expression were 82.4% and 89.7% in distinguishing neuroendocrine carcinomas from neuroendocrine tumors of the lung, 40.6% and 100% to differentiate extrapulmonary neuroendocrine carcinomas from neuroendocrine tumors, and 82.4% and 59.4% in distinguishing lung from extrapulmonary neuroendocrine carcinomas. Our data suggest that achaete-scute homolog 1 is not a site-specific marker. However, achaete-scute homolog 1 may be proposed as a diagnostic marker of poor differentiation and may help to differentiate neuroendocrine carcinomas from neuroendocrine tumors in difficult cases. [ABSTRACT FROM AUTHOR]

Objectives: To provide a comprehensive review of the clinical and histopathological features of olfactory neuroblastoma (ONB) and other sinonasal neuroendocrine neoplasms (NENs), in order to refine diagnostic criteria, analyze treatment outcomes, and identify prognostic factors.Methods: Data from an Italian multi-institutional database were analyzed. Patients were treated surgically via a minimally-invasive endoscopic approach followed by adjuvant radiotherapy or radiochemotherapy. Neoadjuvant cisplatin/etoposide chemotherapy was administered in cases of poorly-differentiated tumors. A centralized pathology review was performed in all cases. Patients were prospectively observed for survival. Overall (OS) and Disease-free survival (DFS) estimates were determined from Kaplan-Meier analysis and compared using the log-rank test. Statistically significant variables were entered in a multivariate Cox regression model.Results: 98 patients with a median follow-up of 53months were included. Morphology review and the incorporation of cytokeratin 8/18 in the immunohistochemical panel modified the final diagnosis in 8/98 (8.2%) cases. The neoplasms were ultimately classified into four groups with different immunohistochemical profiles and clinical behaviors: ONB in 67 cases (5-year-OS, 91.6%); NEC (poorly-differentiated neuroendocrine carcinoma) in 22 cases (5-year-OS, 42.6%); MiNEN (mixed neuroendocrine/non-neuroendocrine neoplasm) in five cases (5-year-OS, 0%,0/5 cases); and NET (well-differentiated neuroendocrine tumor) in four cases (5-year-OS, 50%, 2/4 cases). Hyams grade and Ki67 index were independent prognostic factors for ONB. Neoadjuvant chemotherapy appeared to be associated with improved OS and DFS for NEC, independent of other clinicopathological variables.Conclusions: Induction chemotherapy improves survival outcomes in patients affected by poorly-differentiated tumors. Recent advances in histopathological diagnosis, including CK8/18 staining, allow to plan the most appropriate range of multimodal treatments. [ABSTRACT FROM AUTHOR]