REPORT OF A CASE
A 19-year-old white man was referred for evaluation of multiple cystic lesions on his chest and abdomen present since childhood. The lesions, while persistent, were asymptomatic and never inflamed.Physical examination revealed multiple, 2- to 4-mm, flesh-colored to slightly erythematous, soft, papulocystic lesions on the patient's chest and abdomen (Figures 1 and 2). Most of the cysts had smooth surfaces but a few possessed hyperkeratotic crusts. The lesions were not grouped.A skin biopsy specimen from the patient's abdomen was obtained for routine histopathologic study (Figures 3 and 4).What is your diagnosis?
Eruptive vellus hair cysts (EVHC).
Hematoxylin-eosin—stained sections revealed a small, keratin filled cyst in the middle dermis (Figure 3) containing vellus hair cut in longitudinal and cross section (Figure 4). The cyst was associated with chronic granulomatous inflammation and fibrosis.
Armstrong CR, Yeager JK, Vidmar DA. Multiple Papulocystic Lesions on the Trunk. Arch Dermatol. 1995;131(3):346. doi:10.1001/archderm.1995.01690150111024