PRAME

PO

Definition : Preferentially expressed antigen in melanoma (PRAME) is a tumor-associated repressor of retinoic acid signaling which is expressed in melanoma and has emerged as a potential biomarker for malignant behavior in melanocytic neoplasms.

PRAME protein expression in normal tissues is congruent with original molecular data being present in the testis, and at low levels in the endometrium, adrenal cortex, and adult as well as fetal ovary.

In tumors, there is diffuse PRAME immunoreactivity in most metastatic melanomas, myxoid liposarcomas, and synovial sarcomas.

Other neoplasms such as seminomas and carcinomas of various origins including endometrial, serous ovarian, mammary ductal, lung, and renal showed an intermediate proportion of cases and variable extent of tumor cells positive for PRAME protein expression. PMID: 33890816

PRAME positivity is more common in melanocytic neoplasms favored to be malignant by histopathologic evaluation. Its clinical utility may include early diagnosis of incipient melanoma in situ.

Rarely, benign melanocytic neoplasms can show diffuse expression of PRAME. PRAME positive staining can be encountered in atypical intraepidermal melanocytic proliferations and spitzoid neoplasms. (33660310)