Multifocal Osteosarcoma Involving Unusual Sites

Multifocal Osteosarcoma: Unusual Presentation and Imaging Findings

Multifocal osteosarcoma is usually defined as the occurrence of a tumor at 2 or more sites in a patient without pulmonary metastases and may be synchronous with more than one lesion seen at presentation or metachronous with new tumors developing after the initial treatment. It is difficult to determine whether these represent synchronous multiple primary lesions or metastases. We present a rare case of widespread synchronous multifocal osteosarcoma and a brief review of the literature.

Multifocal osteosarcoma of the skull: multiple primary or metastatic? A case report

Osteosarcoma of the skull is a very rare condition. Moreover, it is extremely rare for osteosarcoma to present as multiple lesions confined to the skull. A 58-year-old woman was admitted with two masses in the parietal area of the skull, accompanied by mild headache and tenderness. Imaging revealed two masses with a heterogeneous consistency in the cranial bones. Excision craniectomy was performed and the pathology was consistent with osteoblastic osteosarcoma. Two nodules in the heart were found on routine follow-up imaging while the patient was undergoing chemotherapy. The nodules were biopsied and found to be metastatic osteosarcoma.

Multicentric osteosarcoma: clinicopathologic and radiographic study of 56 cases

Multicentric osteosarcoma (M-OGS) is characterized by multicentricity of osseous osteosarcomas, either synchronous or metachronous, without visceral involvement. The study's purpose was to clinicopathologically and radiographically analyze 56 cases of M-OGS (22 synchronous and 34 metachronous). The distal femur was the most common site. Histologically, all tumors were high grade. Of 22 patients with synchronous M-OGS, 16 had 3 or more simultaneous tumors; the axial skeleton was involved in 14 (64%) of 22 cases. In metachronous M-OGS, the second malignancy occurred after a median of 22 months. Treatment was surgery, chemotherapy, radiotherapy, or a combination of these. Patients with metachronous osteosarcoma had a median survival longer than did patients with synchronous tumors. Overall, 8 long-term survivors were treated by aggressive surgery with wide margins (plus chemotherapy and/or radiotherapy). M-OGS combines multiple skeletal locations of high-grade conventional osteosarcomas and has a poor prognosis. Aggressive surgery may result in improved long-term survival, particularly in patients with metachronous disease.