Congenital Smooth Muscle Hamartoma with Follicular Spotted Appearance / 대한피부과학회지

A congenital smooth muscle hamartoma is a rare benign cutaneous abnormality and histologically characterized by smooth muscle hyperplasia with a great number of long and straight bundles of smooth muscle at various angles of the orientation, throughout the dermis. A congenital smooth muscle hamartoma usually presents as a congenital hairy patch or plaque with or without hyperpigmentation on the trunk or extremities. The congenital smooth muscle hamartoma with follicular spotted appearance is a rare clinical variant, and is appeared as a patch with marked follicular papules. Herein, we report a 16-year-old girl with this rare patch follicular variant of congenital smooth muscle hamartoma, on the left upper arm.