title: Malignant melanoma presenting as a mediastinal mass.
abstract: A case of malignant melanoma presenting as a mediastinal mass without an extrathoracic primary is reported. Microscopically the tumor appeared consistent with malignant melanoma, with the presence of focal melanin pigment in large epithelioid cells. Fontana stain confirmed the presence of melanin pigment. Immunohistochemical staining further suggested melanoma, with the tumor cells expressing a HMB45+, S100+ and cytokeratin-phenotype. Electron microscopy showed an abundance of melanosomes confirming the diagnosis of malignant melanoma.
authors.affiliation: Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: C L
authors.initials: CL
authors.lastname: Lau
authors.forename: R C
authors.initials: RC
authors.lastname: Bentley
authors.forename: J P
authors.initials: JP
authors.lastname: Gockerman
authors.forename: L G
authors.initials: LG
authors.lastname: Que
authors.forename: T A
authors.initials: TA
authors.lastname: D'Amico
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008479:Mediastinal Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D008545:Melanoma / Q000737:chemistry / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D011859:Radiography