NRAS Q61R -driven atypical melanocytic tumor with blue nevus-like morphology: A case report.

Autor: Hiraki T; Department of Diagnostic Pathology, Shizuoka Cancer Center Hospital, Sunto, Japan., Mori H; Department of Diagnostic Pathology, Hamamatsu Medical Center, Hamamatsu, Japan., Misawa J; Department of Dermatology, Hamamatsu Medical Center, Hamamatsu, Japan., Yunoki M; Department of Dermatology, Hamamatsu Medical Center, Hamamatsu, Japan.; Department of Dermatology & Skin Oncology, Chutoen General Medical Center, Kakegawa, Japan., Goto K; Department of Diagnostic Pathology, Shizuoka Cancer Center Hospital, Sunto, Japan.; Department of Pathology, Tokyo Metropolitan Cancer and Infectious Disease Center Komagome Hospital, Tokyo, Japan.; Department of Anatomic Pathology, Tokyo Medical University, Tokyo, Japan.; Department of Diagnostic Pathology, Chutoen General Medical Center, Kakegawa, Japan.; Department of Diagnostic Pathology and Cytology, Osaka International Cancer Institute, Osaka, Japan.; Department of Diagnostic Pathology, Osaka National Hospital, Osaka, Japan.; Department of Dermatology, Hyogo Cancer Center, Akashi, Japan.; Department of Dermato-Oncology/Dermatology, National Hospital Organization Kagoshima Medical Center, Kagoshima, Japan.
Jazyk: angličtina
Zdroj: Journal of cutaneous pathology [J Cutan Pathol] 2024 Dec; Vol. 51 (12), pp. 948-953. Date of Electronic Publication: 2024 Aug 23.
DOI: 10.1111/cup.14709
Abstrakt: NRAS Q61 mutations are driver genetic alterations associated with common melanocytic nevi. Herein, we describe a case of NRAS-mutant melanocytic tumor with a blue nevus-like morphology. A 71-year-old Japanese man presented with a 4.6-mm nodule on his back. Histopathological examination revealed a dense distribution of spindle-shaped melanocytes in the upper dermis and a sparse distribution of dendritic melanocytes in the mid-dermis. The vertical periadnexal extension reached the deep dermis at the center of the tumor. A small junctional component, hyperpigmentation, sclerotic stroma, mild nuclear atypia, and a few mitotic figures were observed. Immunohistochemical examination revealed no PRAME expression and preserved p16 expression. Diffuse RASQ61R immunoreactivity was observed in these tumor cells. Nuclear β-catenin expression was not observed. Targeted RNA sequencing revealed two mutations, NRAS c.182A>G (Q61R) and FGFR2 c.-157A>G, but no other pathogenic alterations such as BRAF, GNAQ, GNA11, CTNNB1, PRKAR1A, or IDH1 mutations or kinase gene fusions. The histopathology fits that of compound-type blue nevus, which is called "Kamino nevus"; however, this tumor was genetically considered to be on the spectrum of conventional acquired melanocytic nevi but not on that of blue nevi. Morphologically, NRAS-driven melanocytic nevi resemble blue nevi without IDH1 R132C coexistence.
(© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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