Steatocystoma multiplex presenting as acral subcutaneous nodules.

A 47-year-old Japanese housewife was referred to our hospital with asymptomatic subcutaneous nodules on her forearms. She first noticed the subcutaneous nodules 10 years previously, and they had gradually increased in both size and number. They were not associated with any pain or tenderness. Her family history and past clinical history were unremarkable. Physical examination revealed multiple, mobile, well-defined, elastic-hard, 5–10 mm subcutaneous nodules on the flexor surface of the forearms; 8 on the right and 3 on the left (Fig. 1). There were no other lesions except for the forearms and no nail changes. Clinically, the lesions were initially thought to be multiple lipomas and an excisional biopsy was performed to confirm the suspected diagnosis. Upon biopsy, a well-circumscribed ovoid cyst was isolated in the superficial subcutaneous fat layer. The cyst contained yellow creamy material. Biopsy specimen showed a well-encapsulated subcutaneous cyst with infolded walls lined by squamous epithelium without a granular layer. Sebaceous gland lobules are found within the cyst wall (Fig. 2). From these findings, the diagnosis of SM was finally made. DISCUSSION