NeuN, a DNA-binding neuron-specific protein expressed by Merkel cell carcinoma: analysis of 15 cases.

Content Provider	Europe PMC
Author	Ungari, Marco Manotti, Laura Tanzi, Giulia Varotti, Elena Ferrero, Giuseppina Gusolfino, Marino Daniel Trombatore, Monica Cavazzuti, Laura Tolomini, Miriam
Copyright Year	2021
Abstract	SummaryAimMerkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine carcinoma, with an increasing worldwide incidence. It presents as a painless red to purple nodule on sun-exposed skin. MCC is presumed to arise from resident cutaneous Merkel cells. The pathogenesis of MCC is likely multifactorial with immunosuppression, UV-induced skin damage, and Merkel cell polyomavirus contributing to the development. The diagnosis of MCC relies upon characteristic morphologic features and use of immunohistochemical stains. Histologically, the differential diagnosis of Merkel cell carcinoma includes the ‘small round cell’ tumor group, particularly metastatic small cell carcinoma and hematological malignancies. This study investigates the expression of NeuN antibody, which recognizes the protein NeuN, normally present in most neuronal cell types and neuronal tumors, in Merkel cell carcinomas.Methods and resultsFifteen cases of Merkel cell carcinoma (7 men and 7 women; mean age 74 years) were retrieved from the institute database between the years 2011-2020. The immunohistochemical profile was investigated: CK20 (14/14), Neurofilament, (12/12), Synaptophysin (14/14); Chromogranin A (11/13), PAX5 (10/12), TDT (5/12), CK7 (1/14), TTF1 (0/14). Infection by Polyoma virus was detected in 11 of 14 patients. Most tumors showed middle/strong expression of NeuN. No cutaneous structures, or epidermal Merkel cells, showed expression of NeuN. The expression of NeuN was investigated in 17 primary small cell lung carcinomas: 2 cases were positive for Neu-N.ConclusionsAwareness of the staining pattern of Neu-N could aid in diagnosis of Merkel cell carcinoma, avoiding misinterpretation and erroneous diagnosis with other tumors.
Related Links	https://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC8720396&blobtype=pdf
Page Count	6
ISSN	00312983
Journal	Pathologica
Volume Number	113
PubMed Central reference number	PMC8720396
Issue Number	6
PubMed reference number	34974547
e-ISSN	1591951X
DOI	10.32074/1591-951x-195
Language	English
Publisher	Pacini Editore srl
Publisher Date	2021-12-01
Access Restriction	Open
Rights License	This is an open access journal distributed in accordance with the CC-BY-NC-ND (Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International) license: the work can be used by mentioning the author and the license, but only for non-commercial purposes and only in the original version. For further information: https://creativecommons.org/licenses/by-nc-nd/4.0/deed.en © 2021 Copyright by Società Italiana di Anatomia Patologica e Citopatologia Diagnostica, Divisione Italiana della International Academy of Pathology
Subject Keyword	Merkel cell carcinoma neuroendocrine carcinoma NeuN Merkel cell polyomavirus small cell lung carcinoma
Content Type	Text
Resource Type	Article
Subject	Pathology and Forensic Medicine