title: Dedifferentiated parosteal osteosarcoma with giant cell tumor component.
abstract: Dedifferentiated parosteal osteosarcoma is characterized histologically by the admixture of low-grade fibroblastic osteosarcoma and a high-grade component typically resembling conventional osteosarcoma or malignant fibrous histiocytoma. We report an unusual distal femoral dedifferentiated parosteal osteosarcoma in which the dedifferentiated component resembled a giant cell tumor of bone. This phenotype is rarely described in the dedifferentiated component of a dedifferentiated parosteal osteosarcoma. The clinical, radiographic, and pathologic features of this unusual tumor are described to further expand the histologic spectrum of dedifferentiated parosteal osteosarcoma.
authors.affiliation: Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, College of Medicine, P.O. Box 100275, Gainesville, FL 32601-0275, USA.
authors.forename: Diana M
authors.initials: DM
authors.lastname: Cardona
authors.forename: Jacquelyn A
authors.initials: JA
authors.lastname: Knapik
authors.forename: John D
authors.initials: JD
authors.lastname: Reith
mesh_terms: D000328:Adult; D001707:Biopsy, Needle; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D003937:Diagnosis, Differential; D017809:Fatal Outcome; D005266:Femoral Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D005870:Giant Cell Tumors / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D018217:Osteosarcoma, Juxtacortical / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D010641:Phenotype; D014055:Tomography, Emission-Computed