title: Giant cell tumor of soft tissue arising in breast.
abstract: Primary giant cell tumor of soft tissue (GCT-ST) arising in breast is exceedingly rare. We report a case of a 60-year-old woman with a primary breast giant cell tumor that appeared histologically identical to giant cell tumor of bone and had a clinically malignant course. The patient presented with a cystic mass of the breast, suspected on imaging to be an organizing hematoma, possibly related to previous injury. Histopathological evaluation revealed a neoplasm composed of mononuclear cells admixed with osteoclast-like giant cells resembling giant cell tumor of bone. Immunohistochemical staining was positive for CD68, smooth muscle actin, and vimentin, but was negative for a panel of epithelial and additional muscle markers. These features were most consistent with GCT-ST, an uncommon neoplasm of low malignant potential. Despite aggressive surgical treatment achieving clear surgical margins, the patient expired with pulmonary metastases within a year of her initial presentation. This case demonstrates the difficulty of predicting clinical behavior of GCT-ST of breast on the basis of histological features and depth of tumor alone. To our knowledge, this is the first case report of a GCT-ST arising in the breast associated with a fatal outcome. The distinction of this entity from other more common primary breast tumors with giant cell morphology is also emphasized.
authors.affiliation: Department of Pathology, Unit 085, The University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA.
authors.forename: Steve A
authors.initials: SA
authors.lastname: May
authors.forename: Michael T
authors.initials: MT
authors.lastname: Deavers
authors.forename: Erika
authors.initials: E
authors.lastname: Resetkova
authors.forename: Deborah
authors.initials: D
authors.lastname: Johnson
authors.forename: Constance T
authors.initials: CT
authors.lastname: Albarracin
mesh_terms: D000199:Actins / Q000378:metabolism; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D001943:Breast Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005870:Giant Cell Tumors / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D008875:Middle Aged; D012983:Soft Tissue Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D014746:Vimentin / Q000378:metabolism; D000097382:CD68 Molecule
chemical_list: D000199:Actins; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D014746:Vimentin; C067980:CD68 antigen, human; D000097382:CD68 Molecule