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Merkel cell carcinoma is a rare (∼ 2000 cases/year in the USA) but aggressive neuroendocrine neoplasm of the skin. In 2008, the Merkel cell polyomavirus (MCPyV) was found to be clonally integrated in approximately 80% of Merkel cell carcinomas. The remaining 20% have large numbers of UV-associated mutations. Importantly, both the UV-induced neoantigens in virus-negative Merkel cell carcinoma and the Merkel cell polyomavirus oncogenes that are required for virus-positive tumor growth are highly immunogenic. Indeed, antigen-specific T cells detected in patients are frequently "dysfunctional/exhausted," and the inhibitory ligand PD-L1 is often expressed by Merkel cell carcinoma cells. These data led to point our attention on the quantity and the quality of the immune response in Merkel cell carcinoma. Here, we found CD8+ lymphocytes are the only singly evaluated lymphocyte subclass that strongly influenced overall survival and disease-specific survival in Merkel cell carcinoma. In addition, we highlighted as Merkel cell polyomavirus is a strong prognostic factor and as it prompts a host immune response involving various lymphocyte subclasses (CD3, CD8, FoxP3, and PD-L1 positive) in MCC. For this reason, we proposed a novel eye-based "immunoscore" model, obtained by tumor infiltrating lymphocytes subtyping (CD3, CD8, FoxP3, and PD-L1) that could provide additional prognostic information in Merkel cell carcinoma.

Mixed neuroendocrine-nonneuroendocrine neoplasm (MiNEN) consisting of adenoma and well-differentiated neuroendocrine tumor (NET) has been recently defined as "MANET." However, the clinico-pathologic and pathogenetic features of this entity are not thoroughly studied. We examined the clinico-pathologic features of 12 MANETs by expanding their p53 and β-catenin expression profiles as well as the presence of microsatellite instability and KRAS, BRAF, and PIK3CA mutations in the 2 tumor components. In all cases, the adenomatous component represented the larger part of the lesions and the NET was localized in the deep central portion of polyps. In 9 cases the latter was represented by NET G1, in 2 by NET G2, and in 1 by NET G3. In all cases, the glandular and NET components were intimately admixed, with zone of transition between the tumor components. The NET component was p53 negative in all cases and 3 of 8 cases showed variable nuclear positivity for β-catenin. All patients with follow-up data were alive and free of disease after a mean follow-up time of 9 years. No mutations in KRAS, BRAF, and PIK3CA genes and no microsatellite instability were found in both tumor components. Review of the literature also identified 59 previously reported MANETs and no tumor-related death has been found. Like mixed adenoneuroendocrine carcinomas, a high-grade malignant form of MiNENs with a poorly differentiated neuroendocrine carcinoma component, a common origin for both tumor constituents may be hypothesized. Moreover, the current series provides evidence that MANET is an indolent disease that needs to be distinguished from aggressive high-grade MiNENs.

Background: Little is known on racial differences in patients with diffuse large B-cell lymphoma (DLBCL). The aim of this retrospective study is to compare characteristics, prognostic factors and outcomes of Asian and Western patients with DLBCL treated with rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP)., Methods: Patient-level data was collected from 8 centers. All patients were diagnosed with DLBCL and treated with R-CHOP. Patients were divided into Asian and Western, according to the country of report. Comparisons and univariate/multivariate survival analyses were performed., Results: 712 patients, 455 Asian and 257 Western patients were included. Westerners were more likely to present with elevated LDH (64% vs. 48%, p<0.01) and advanced stage (58% vs. 49%, p<0.01). After a median follow-up of 36 months, there was no difference in progression-free (PFS; p=0.33) or overall survival (OS; p=0.69). There were no PFS or OS differences between races when evaluating separately each age-adjusted International Prognostic Index category. In the multivariate analyses, performance status and stage were associated with PFS and OS in both races., Conclusions: There are no differences in prognostic factors, PFS and OS between Asian and Western patients with DLBCL treated with R-CHOP., (Copyright © 2013 Elsevier Ltd. All rights reserved.)