Guess what! Eruptive vellus hair cysts

An otherwise healthy 24-year-old woman presented with persistent asymptomatic skin-coloured papular lesions on her trunk which had appeared over 18 months, gradually increasing in number, size and the extent of the skin surface area involved. Physical examination revealed multiple flesh - to whitish - coloured papules, 2 to 5 mm in diameter, located on her neck, anterior chest wall, axillae and upper abdomen (Fig. 1). The lesions were smooth, painless on palpation and not grouped. Laboratory investigations only showed normal results. Histopathological examination of a papular lesion from the upper abdomen revealed a cystic structure in the mid-dermis lined by four to five layers of squamous epithelium with a discrete granular layer. Laminated keratinous material and multiple transversely or obliquely cut vellus hairs were present within the cyst, while sebaceous elements were lacking in the vicinity or within the cyst wall (Fig. 2a, b). Polaroscopic examination demonstrated double refractile vellus hairs in the cyst.