title: Extraskeletal osteosarcoma of the jaw.
abstract: Extraskeletal osteosarcoma is a rare malignancy, which accounts for 1-2% of all soft tissue sarcomas; occurrence of these tumors in the head and neck is extremely rare. We present a case of extraskeletal osteosarcoma arising in the subcutaneous tissue of the jaw angle, the central portion of which displayed calcification. Imaging findings were interesting in terms of a high grade malignancy in that the tumor was small and well circumscribed; its appearance mimicked a calcified lymph node. The differential diagnosis of this lesion as well as the imaging and pathological features of extraskeletal osteosarcoma are discussed.
authors.affiliation: Department of Orthopedic Surgery, Niigata Cancer Center, 2-15-3, Kawagishi-Cho, 951-8566 Niigata City, Japan. hatanoh@niigata-cc.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hatano
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Morita
authors.forename: Hiroto
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Takui
authors.initials: T
authors.lastname: Ito
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Segawa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hasegawa
mesh_terms: D000328:Adult; D003131:Combined Modality Therapy; D003937:Diagnosis, Differential; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D006801:Humans; D007568:Jaw; D008279:Magnetic Resonance Imaging; D008297:Male; D012516:Osteosarcoma / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D014057:Tomography, X-Ray Computed