title: Malignant Glomus Tumor Arising in a Long Standing Precursor Lesion.
abstract: Malignant glomus tumor is an exceedingly rare vascular malignancy of unclear etiology, which is believed to arise de novo or from malignant transformation of a benign glomus tumor. The authors present a case of an elderly woman evaluated for a painful 2.5-cm purple-brown tumor on the right forearm that grew rapidly within a long-standing, seemingly benign lesion. An excisional biopsy revealed a multilobular dermal tumor composed of areas of benign-appearing glomus tumor cells interspersed with areas of dense, pleomorphic cells arranged in sheets and fascicles with an elevated mitotic rate. The diagnosis of malignant glomus tumor was made on the basis of the lesion's nuclear atypia and elevated mitotic rate. This case demonstrates malignant transformation of a presumably benign glomus tumor precursor lesion highlighting this rarely reported phenomenon. The authors present this case to raise awareness of this vascular malignancy that carries a significant risk of metastasis.
authors.affiliation: *Department of Dermatology, Georgetown University Hospital, Washington Hospital Center, Washington, DC; and †Mid-Atlantic Pathology Services, Inc, Sterling, VA.
authors.forename: Ali Alexander
authors.initials: AA
authors.lastname: Damavandy
authors.forename: Florencia
authors.initials: F
authors.lastname: Anatelli
authors.forename: Maral Kibarian
authors.initials: MK
authors.lastname: Skelsey
mesh_terms: D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D001706:Biopsy; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic; D005260:Female; D005918:Glomus Tumor / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D012878:Skin Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D013997:Time Factors; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D014408:Biomarkers, Tumor