A healthy 11-year-old boy presented with multiple cribriform plaques over different parts of his body. He first developed circumscribed pitted lesions on his left cheek, right ear, right side of his neck, and penis at 4 years of age. With time, they progressively extended, causing cosmetic concern. They were asymptomatic except for occasional expression of cheesy material on pressure. On examination there was a well-defined plaque measuring 7.5 cm × 5 cm on his left cheek, studded with groups of pits filled with black, keratinous plugs (Fig. 1). Similar lesions were found on the right side in a linear pattern extending from his chest to the side of his neck, face, and the concha of his right ear (Fig. 2). Two intradermal nodules were present on the neck. Lesions were also found at the midline of his back and at the penoscrotal junction. The palms, soles, and mucosae were not involved. No other family member was affected. A skin biopsy specimen was taken from a lesion over his right clavicle and stained with hematoxylin-eosin (Fig. 3).
WHAT IS YOUR DIAGNOSIS?
Diagnosis: Nevus Comedonicus
HISTOPATHOLOGYThe epidermis was acanthotic, with deep and wide invaginations filled with concentric lamellae of keratin (Fig. 3). In places, keratin-filled cystic follicles were seen.The basal layer showed abundant melanin and dermal structures were normal.
CLINICAL COURSEExcision was advised for a few localized linear lesions. Topical retinoids were tried for the large lesion on his left cheek, without significant improvement, and he is awaiting dermabrasion.