Dense Papules on the Face: A Quiz

Abstract

A 28-year-old man presented with multiple asymptomatic papules and plaques on his face for 3 months. He denied any drug intake, allergy or trauma history. A dermatological examination revealed clusters of yellowish-erythematous papules and plaques on his face and scalp ( Fig. 1). No lymph adenopathy or visceromegalies were found. Routine laboratory tests, chest radiography and abdominal ultrasound revealed no obvious abnormalities. Biopsy of a lesion from his cheek showed a nodular mixed inflammatory infiltrate throughout the dermis (Fig. 2a). The infiltration consisted of clustered large foamy-appearing histiocytes, numerous lymphocytes, plasma cells and few neutrophils. Emperipolesis in histiocytes was noted (Fig. 2b). Immunohistochemical studies showed that the pale cells were positive for S100 ( Fig. 2c) and CD68, but negative for CD1a. Specific stainings for microbial infections were negative.