Clinical and dermoscopic features of cutaneous BAP1-inactivated melanocytic tumors: Results of a multicenter case-control study by the International Dermoscopy Society

Background: Multiple BRCA1-associated protein 1 (BAP1)-inactivated melanocytic tumors (BIMTs) have been associated with a familial cancer syndrome involving germline mutations in BAP1. Objectives: We sought to describe the clinical and dermoscopic features of BIMTs. Methods: This was a retrospective, multicenter, case-control study. Participating centers contributed clinical data, dermoscopic images, and histopathologic data of biopsy-proven BIMTs. We compared the dermoscopic features between BIMTs and control patients. Results: The dataset consisted of 48 BIMTs from 31 patients (22 women; median age 37 years) and 80 control patients. Eleven patients had a BAP1 germline mutation. Clinically, most BIMTs presented as pink, dome-shaped papules (n = 24). Dermoscopically, we identified 5 patterns: structureless pink-to-tan with irregular eccentric dots/globules (n = 14, 29.8%); structureless pink-to-tan with peripheral vessels (n = 10, 21.3%); structureless pink-to-tan (n = 7, 14.9%); a network with raised, structureless, pink-to-tan areas (n = 7, 14.9%); and globular pattern (n = 4, 8.5%). The structureless with eccentric dots/globules pattern and network with raised structureless areas pattern were only identified in BIMT and were more common in patients with BAP1 germline mutations (P < .0001 and P = .001, respectively). Limitations: Limitations included our small sample size, retrospective design, the absence of germline genetic testing in all patients, and inclusion bias toward more atypical-looking BIMTs. Conclusions: Dome-shaped papules with pink-to-tan structureless areas and peripheral irregular dots/globules or network should raise the clinical suspicion for BIMT.