Broadening the List of Basal Cell Carcinoma Mimickers: Dermoscopic Features of Trichoadenoma.

Abstract

A wide spectrum of skin tumors may mimic basal cell carcinoma (BCC) on both clinical and dermoscopic appearance. Among these, adnexal skin neoplasms and in particular benign follicular tumors are commonly indistinguishable from BCC [1]. Benign follicular tumors are uncommon skin neoplasms, mainly represented by trichoblastoma and trichoepithelioma; however, other rarer subtypes may be also encountered, such as trichoadenoma, trichofolliculoma, and panfolliculoma. To the best of our knowledge, no reports have previously described the dermoscopic appearance of trichoadenoma. Herein we report a case of a man in his 40s who had a long-standing 5-mm papule located on his left eyebrow; the lesion was flesh-colored, firm, and painless (Figure1A). Open in a separate window Figure 1 (A) Clinical picture revealing a 5-mm flesh-colored papule over the left eyebrow of a 45-year-old man. (B,C) Dermoscopic pictures with polarized light, without (B) and with (C) compression. On-focus linear vessels may be seen when compression was not applied; in addition, an ovoid blue-gray area was visible at the periphery of the tumor. When compression was not applied, white structures were more visible: in particular, shiny white lines (black arrows) and small whitish circles (red arrows). (D) At histological examination, the dermis showed irregularly shaped keratinous cysts, many filled with keratotic material and lined with stratified squamous epithelium with epidermoid differentiation. Some cysts were superficial and opened into the epidermis (hematoxylin and eosin, ×40). [Copyright: ©2019 Pampena et al.]