A Case of Congenital Smooth Muscle Hamartoma / 대한피부과학회지

ABSTRACT

Congenital smooth muscle hamartoma usually presents as a well-circumscribed, hypertrichotic, hyperpigmented or skin colored patch or plaque on the trunk or an extremity at birth. Histologically, numerous thick, long, well defined bundles of smooth muscle fibers are scattered throughout the dermis in various directions. We report a case of congenital smooth muscle hamartoma in an 8-month-old female infant who showed hypertrichotic, skin colored plaque on the lumbosacral area since at birth. The pseudo-Darier sign was positive. Histopathologic findings were numerous, well-defined bundles of smooth muscle fibers in the dermis (H and E, Masson-trichrome stain).