Glomus tumor

A glomus tumor, also called a solitary glomus tumor, is a rare neoplasm that arises from the glomus body, a specialized structure of modified smooth muscle cells involved in regulating skin temperature, and it accounts for less than two percent of all soft tissue tumors. Most glomus tumors are benign, though malignant variants occur, and they are most often found under a fingernail, on a fingertip, or elsewhere on the hand, wrist or foot, with rare cases reported in the stomach lining or genital area. The lesions are characteristically small, solitary and intensely painful, often with a bluish or occasionally whitish discoloration visible through the skin or nail, elevation of the nail bed, and a hallmark sensitivity to cold in which pain is reproduced when the affected area is placed in cold water. Familial cases have been linked to inherited deletions in the GLMN gene passed on in an autosomal dominant pattern, and surgical excision remains the preferred treatment for benign tumors.