title: Telangiectatic osteosarcoma of the patella.
abstract: Although osteosarcoma is the most common primary malignancy of bone, it has only been reported to arise from the patella in a handful of cases. Telangiectatic osteosarcoma accounts for <5% of all osteosarcomas, and it is distinguished histologically by spaces, often blood filled, separated by septa containing highly malignant cells and radiographically by a predominately lytic and/or expansile component. Telangiectatic osteosarcoma can be radiologically confused with aneurysmal bone cyst or giant cell tumor. A 22-year-old otherwise healthy man presented with increasing pain, swelling, and limited flexion of the right knee after failing physical therapy for anterior knee pain. Standard anteroposterior and lateral radiographs demonstrated a diffuse destructive process involving the majority of the patella (including loss of the inferior patellar cortex) and a lytic lesion of the proximal tibia. Apparent osteoid matrix was visible in the soft tissue extension along the inferior pole of the patella. A computed tomography scan of the chest showed 2 pulmonary nodules consistent with metastatic disease. Evaluation of core needle biopsy showed osteosarcoma with telangiectatic features. Given that the majority of the tumor involved the patella/extensor mechanism, it was clear that the tumor originated in the patella. This case presents the first published report of a telangiectatic osteosarcoma arising from the patella.
authors.affiliation: Department of Surgery, King Hussein Cancer Center, Amman, Jordan.
authors.forename: Ahmad M
authors.initials: AM
authors.lastname: Shehadeh
authors.forename: Moutaz A
authors.initials: MA
authors.lastname: Haiba
authors.forename: Robert M
authors.initials: RM
authors.lastname: Henshaw
authors.forename: Ernest
authors.initials: E
authors.lastname: Lack
mesh_terms: D001859:Bone Neoplasms / Q000150:complications / Q000473:pathology* / Q000601:surgery*; D006801:Humans; D008297:Male; D012516:Osteosarcoma / Q000150:complications / Q000473:pathology* / Q000601:surgery*; D010329:Patella / Q000473:pathology* / Q000601:surgery*; D013684:Telangiectasis / Q000150:complications / Q000473:pathology* / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult