RASGRF1-rearranged Cutaneous Melanocytic Neoplasms With Spitzoid Cytomorphology: A Clinicopathologic and Genetic Study of 3 Cases.
Am J Surg Pathol
; 46(5): 655-663, 2022 05 01.
Article
em En
| MEDLINE
| ID: mdl-34799483
ABSTRACT
Spitz neoplasms, according to 2018 WHO Blue Book, are morphologically defined by spindled and/or epithelioid melanocytes and genetically by either HRAS mutations or kinase gene fusions. The terminology "spitzoid" refers to lesions with similar morphology but with alternate or undefined genetic anomalies. Herein, we present 3 melanocytic neoplasms with a spitzoid cytomorphology, variable nuclear atypia, and harboring undescribed fusions involving RASGRF1. Two cases presented as unpigmented papules on the heel of a 26-year-old female (case 1) and the forearm of a 13-year-old boy (case 2). They were classified as low-grade melanocytomas (WHO 2018). The third case appeared as a pigmented ulcer on the sole of a 72-year-old female (case 3) that displayed diagnostic features of an invasive melanoma (Breslow thickness 6 mm, Clark level V). A wide skin reexcision identified an epidermotropic metastasis, and sentinel lymph node biopsy displayed multiple subcapsular metastatic deposits. RNA sequencing revealed CD63RASGRF1, EHBP1RASGRF1, and ABCC2RASGRF1 fusions in cases 1 to 3, respectively. They were confirmed by a RASGRF1 break-apart fluorescence in situ hybridization technique. Translocations of RASGRF1, a gene coding a guanine nucleotide exchange factor but not a kinase, have rarely been reported in tumors. While all these cases showed spitzoid cytomorphology, it is too early to tell if they are true Spitz neoplasms as currently defined.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias Cutâneas
/
Nevo de Células Epitelioides e Fusiformes
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Melanoma
Tipo de estudo:
Prognostic_studies
Limite:
Adolescent
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Adult
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Aged
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Female
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Humans
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Male
Idioma:
En
Revista:
Am J Surg Pathol
Ano de publicação:
2022
Tipo de documento:
Article