Clinical and histologic features of striated muscle hamartoma: possible relationship to Delleman's syndrome.

We describe 5 new cases of striated muscle hamartoma (SMH) and review the 7 cases previously described in the literature. Eleven of the 12 patients had single lesions centrally located on the chin (4), near the ala of the nose (3), on the upper chest (3), and on the upper lip (1). Histologically all of the lesions were characterized by a central core containing bundles and individual fibers of skeletal muscle as well as other mesenchymal elements. The muscle fibers penetrated the dermis among numerous folliculo-sebaceous structures. Of the 12 cases of SMH, 3 had other associated congenital anomalies including a cleft lip in 1 patient and a thyroglossal duct sinus in another with single lesions, and preauricular sinuses, low-set ears and bilateral sclerocorneas in the case of multiple SMH. The relationship of SMH with oculocerebrocutaneous syndrome is discussed, and we conclude that at least some of the skin appendages associated with that syndrome are SMH.