Sporadic Trichoblastomas and Those Occurring in the Setting of Multiple Familial Trichoepithelioma/Brooke-Spiegler Syndrome Show No BAP1 Loss
Abstract
The BRCA1-associated protein 1 (BAP1) is a tumor suppressor gene located on chromosome region 3p21. Mutations in BAP1 have been demonstrated to increase susceptibility to the development of uveal and cutaneous melanomas, distinctive Spitz nevi, mesothelioma, and loss of BAP1 expression has recently been reported in familial cases of multiple basal cell carcinomas (BCCs) with a germline BAP1 mutation.
Our aim was to study BAP1 expression in trichoblastomas, both solitary sporadic and multiple ones, occurring in the setting of multiple familial trichoepithelioma (MFT)/Brooke-Spiegler syndrome (BSS). A total of 35 neoplasms were studied.
Of these, 17 cribriform trichoblastomas came from 14 patients with MFT and 1 from BSS and 17 sporadic trichoblastomas. In none of the 35 neoplasms was there loss of BAP1, including a case in which there was malignant transformation of trichoblastoma into BCC.