title: Dedifferentiated liposarcoma of the lower extremity with low-grade dedifferentiation and low-grade osteosarcomatous component.
abstract: Dedifferentiated liposarcoma can arise de novo or as a complication of a preexisting well-differentiated liposarcoma. We describe the radiologic and pathologic features of a long-standing liposarcoma with multiple recurrences in a 59-year-old male. Imaging demonstrated a heterogeneous fat-containing mass in the anterior thigh. The adjacent proximal femur showed irregular cortical new bone, eventually followed by intramedullary osteoblastic involvement and pathologic fracture. Histologic assessment at resection revealed dedifferentiated liposarcoma with low-grade osteosarcomatous component. The patient subsequently developed metastatic lesions in the lungs containing osteoid and osteoblastic bone metastases. We discuss the radiologic and pathologic features of this rare entity that, to our knowledge, has previously been reported to directly involve osseous structures in only one other case and discuss the potential pitfalls in diagnosis.
authors.affiliation: Department of Radiology, University of Nebraska Medical Center, 981045 Nebraska Medical Center, Omaha, NE, 68198, USA. azajicek@unmc.edu.
authors.forename: Anna K
authors.initials: AK
authors.lastname: Zajicek
authors.affiliation: Department of Radiology, University of Nebraska Medical Center, 981045 Nebraska Medical Center, Omaha, NE, 68198, USA.
authors.forename: Julia A
authors.initials: JA
authors.lastname: Bridge
authors.affiliation: Department of Radiology, University of Nebraska Medical Center, 981045 Nebraska Medical Center, Omaha, NE, 68198, USA.
authors.forename: Joshua W
authors.initials: JW
authors.lastname: Akers
authors.affiliation: Department of Radiology, University of Nebraska Medical Center, 981045 Nebraska Medical Center, Omaha, NE, 68198, USA.
authors.forename: Sean V
authors.initials: SV
authors.lastname: McGarry
authors.affiliation: Department of Radiology, University of Nebraska Medical Center, 981045 Nebraska Medical Center, Omaha, NE, 68198, USA.
authors.forename: Craig W
authors.initials: CW
authors.lastname: Walker
mesh_terms: D003937:Diagnosis, Differential; D018450:Disease Progression; D005266:Femoral Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D061705:Image-Guided Biopsy; D008080:Liposarcoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D008175:Lung Neoplasms / Q000556:secondary; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local; D012516:Osteosarcoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D013848:Thigh; D014057:Tomography, X-Ray Computed
keywords: CDK4 liposarcoma; Dedifferentiated liposarcoma; MDM2 liposarcoma; Osteosarcomatous dedifferentiation