title: Dedifferentiated parosteal osteosarcoma with rhabdomyosarcomatous differentiation.
abstract: Dedifferentiated parosteal osteosarcomas are characterized histologically by the combination of low-grade fibroblastic osteosarcoma admixed with a high-grade component that typically has the appearance of malignant fibrous histiocytoma or osteosarcoma. Herein we report a case of dedifferentiated parosteal osteosarcoma of the distal femur, in which the high-grade component consisted of rhabdomyosarcoma. To our knowledge, a rhabdomyosarcomatous component has not been described previously in a dedifferentiated parosteal osteosarcoma. The clinical, radiologic, and pathologic features of this rare type of surface osteosarcoma are described.
authors.affiliation: Department of Pathology, Jackson Memorial Medical Center, University of Miami School of Medicine, Miami, Florida, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Reith
authors.forename: F I
authors.initials: FI
authors.lastname: Donahue
authors.forename: F J
authors.initials: FJ
authors.lastname: Hornicek
mesh_terms: D000328:Adult; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D005269:Femur / Q000473:pathology; D006801:Humans; D008175:Lung Neoplasms / Q000556:secondary; D008279:Magnetic Resonance Imaging; D009361:Neoplasm Invasiveness; D012516:Osteosarcoma / Q000175:diagnosis* / Q000473:pathology; D011247:Pregnancy; D011252:Pregnancy Complications, Neoplastic / Q000175:diagnosis*; D012208:Rhabdomyosarcoma / Q000175:diagnosis* / Q000473:pathology; D014057:Tomography, X-Ray Computed