White network in fibroepithelioma of Pinkus

Abstract

First described by Herman Pinkus in 1953 as a premalignant epithelial neoplasm from which a basal cell carcinoma (BCC) may arise,1 fibroepithelioma of Pinkus (FEP) is viewed by most as a subtype of BCC,2, 3, 4 although some view it as a subtype of trichoblastoma.5 FEP classically appears clinically as a solitary skin-colored papule, most often on the lumbosacral region, having a benign appearance that is frequently misdiagnosed as a fibroma, dermal nevus, seborrheic keratosis, or even acrochordon. Histologically, FEP is characterized by anastomosing strands of basaloid epithelial cells embedded within a fibrous stroma. Frequently, FEPs are found in continuity with other histologic subtypes of BCC, such as nodular BCC.2, 3 Dermatoscopic structures observed in FEP include shiny white structures (also known as chrysalis or crystalline structures), fine arborizing vessels, milialike cysts, and ulceration.6 Herein, an additional dermatoscopic finding that may be more specific for FEP, namely, the white network, is reported in 2 cases.