RESUMEN
Cutaneous piloleiomyoma is a benign, often painful, smooth muscle tumor, originating from arrector pili muscle. It is usually present as red-brown nodules on the extensor extremities, and it can be multiple in 80% of patients. A 51-year-old man with multiple papules, nodules and plaques on his left cheek, left chin and left submandibular area visited our department. He had noted papules on his left submandibular area for the past 30 years, which had spread to the left cheek and chin. These lesions caused intense pain on exposure to cold air. Histopathological examination showed a neoplastic aggregation composed of irregular interlacing bundles of smooth muscle cells, in the whole dermis. Immunohistochemical staining with smooth muscle actin was positive in tumor cells. The clinical and histopathological findings led to a diagnosis of segmental piloleiomyomatosis. To our knowledge, this case is a first report of extensive segmental piloleiomyomatosis on the face and neck in Korea.