Atypical Spitz tumor with SQSTM1::NTRK2 fusion: Report of a case with unique spindled cell features.
J Cutan Pathol
; 51(3): 198-204, 2024 Mar.
Article
em En
| MEDLINE
| ID: mdl-38031352
ABSTRACT
A host of signature genetic alterations have been demonstrated in Spitz neoplasms, most notably fusions of kinase genes (including BRAF, ALK, ROS1, NTRK1, NTRK3, RET, MET, MAP3K8) or variants in HRAS. While there are multiple reports of rearrangements involving NTRK1 and NTRK3 in Spitz tumors, there are very few reports of NTRK2-rearranged Spitz nevi in the literature. This report presents an NTRK2-rearranged atypical Spitz tumor with spindled cell features. The patient was a 6-year-old female with a growing pigmented papule on the back. Histopathological evaluation revealed an asymmetric, biphasic, compound proliferation of melanocytes featuring an epithelioid cell population arranged as variably sized nests and single cells along the basal layer with extension down adnexa, as well as a population of spindled melanocytes with desmoplastic features and loss of Melan-A expression in the dermis. There was partial loss of p16 expression in the epidermal component and diffuse loss in the dermal component. Immunohistochemistry for PRAME, ALK, NTRK1, HRAS Q61R, p53, and BRAF V600E were negative. A SQSTM1NTRK2 fusion was identified by RNA sequencing. No TERT promoter hotspot variants were detected. This case report expands the known histopathologic spectrum of genetic alterations in Spitz neoplasms.
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Base de dados:
MEDLINE
Assunto principal:
Neoplasias Cutâneas
/
Nevo de Células Epitelioides e Fusiformes
Limite:
Child
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Female
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Humans
Idioma:
En
Revista:
J Cutan Pathol
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Estados Unidos