title: Amelanotic malignant melanoma of unknown primary origin metastasizing to the bone marrow: a case report and review of the literature.
abstract: We herein describe the case of a 77-year-old Japanese man who presented with progressive thrombocytopenia. No lymphadenopathies, bone lesions, hepatosplenomegaly or masses within any internal organs were detectable. Bone marrow smears revealed diffuse infiltration of large atypical cells morphologically resembling mature lymphoid neoplasms. A flow cytometric analysis showed that the tumor cells strongly expressed CD56 without myeloid or lymphoid antigens, suggesting that they were non-hematologic in origin. Ultimately, amelanotic malignant melanoma of unknown primary origin was diagnosed based on positive immunostaining for S100 proteins, HMB-45 and Melan-A. This case illustrates the usefulness of flow cytometric analyses for making such diagnoses. We also review the available literature on similar cases.
authors: Department of Hematology, Toyokawa City Hospital, Japan.
authors: Tomotaka
authors: T
authors: Suzuki
authors: Shigeru
authors: S
authors: Kusumoto
authors: Shinsuke
authors: S
authors: Iida
authors: Toyohiro
authors: T
authors: Tada
authors: Fumiko
authors: F
authors: Mori
mesh_terms: D000368:Aged; D019046:Bone Marrow Neoplasms / Q000378:metabolism / Q000473:pathology / Q000556:secondary*; D019002:CD56 Antigen / Q000378:metabolism; D017809:Fatal Outcome; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D058965:MART-1 Antigen / Q000378:metabolism; D008297:Male; D018328:Melanoma, Amelanotic / Q000378:metabolism / Q000473:pathology / Q000556:secondary*; D058950:Melanoma-Specific Antigens / Q000378:metabolism; D009382:Neoplasms, Unknown Primary / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology; D009418:S100 Proteins / Q000378:metabolism; D058951:gp100 Melanoma Antigen
chemical_list: D019002:CD56 Antigen; D058965:MART-1 Antigen; C548667:MLANA protein, human; D058950:Melanoma-Specific Antigens; C522918:NCAM1 protein, human; C548637:PMEL protein, human; D009418:S100 Proteins; D058951:gp100 Melanoma Antigen