TY - JOUR
T1 - Atypical Spitz tumor with SQSTM1::NTRK2 fusion: Report of a case with unique spindled cell features
AU - Phillips, Gregory S.
AU - Mengden-Koon, Stephanie
AU - Dhossche, Julie
AU - LeBoit, Philip E.
AU - Goldstein, Alisa M.
AU - Lee, Ina
AU - Raffeld, Mark
AU - Papanicolau-Sengos, Antonios
AU - Sargen, Michael R.
AU - Chung, Jina
N1 - Publisher Copyright:
© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
PY - 2024/3
Y1 - 2024/3
N2 - 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 SQSTM1::NTRK2 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.
AB - 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 SQSTM1::NTRK2 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.
KW - ATM
KW - NTRK2
KW - SQSTM1
KW - atypical Spitz tumor
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U2 - 10.1111/cup.14565
DO - 10.1111/cup.14565
M3 - Article
AN - SCOPUS:85178224624
SN - 0303-6987
VL - 51
SP - 198
EP - 204
JO - Journal of cutaneous pathology
JF - Journal of cutaneous pathology
IS - 3
ER -