Histopathologic examination revealed a fan-shaped array of vertically oriented skeletal muscle fibers in the lower dermis. An additional tightly clustered fascicle of these fibers was observed at the deep margin, and there were isolated, vertically oriented, additional skeletal muscle fibers in the region of the eccrine glands.
Striated muscle hamartoma was first described by Hendrick et al1 in 1986 and was later referred to as rhabdomyomatous mesenchymal hamartoma by Mills2 and congenital midline hamartoma by Elgart and Patterson.3 There have been approximately 16 cases reported in the literature.
Asymptomatic Plaque on the Chin of a 10-Year-Old Girl. Arch Dermatol. 2000;136(10):1263-1268. doi: