3.P.21 PAROSTEAL OSTEOSARCOMA CONCOMITANT WITH DISSEMINATED BREAST CARCINOMA: CLINICAL AND RADIOLOGICAL FINDINGS AND REVIEW OF THE LITERATURE

Abstract

Osteosarcoma arising on the periosteal aspect of bone comprises a biologically heterogeneous group of neoplasm. Parosteal osteosarcoma is a low-grade malignant tumour originates at the surface of bone comprising 3–6% of all osteosarcomas and 2% of primary osseous neoplasms. It is most common in young and middle-aged adults and occurs most frequently on the posterior aspect of the distal femur or tibia. The radiologic appearance is often characterized by a large, lobulated, ossific mass in a juxtacortical position. Cortical thickening without aggressive periosteal reaction can be present. Typically the medullary canal is uninvolved. Wide surgical resection and reconstruction is the treatment of choice. The overall prognosis for patients with this lesion depends on the stage of the tumor at presentation. The prognosis for a Parosteal osteosarcoma is generally excellent.

We present an uncommon case of elderly women 70 year-old with a surface osteosarcoma in right femur concomitant with disseminated Breast Carcinoma. The radiological findings showed a juxtacortical mass on the anteromedial aspect of the junction between the mid-third and the distal third of the right femur with areas of new bone formation mimicking Periostal osteosarcoma. We observed a typical Parosteal osteosarcoma when the biopsy was performed. The elected treatment was a wide resection with PTR MUTARS and adjuvant chemotherapy controlling local and systemic diseases.

In conclusion, due to the treatment for the juxtacortical osteosarcomas varies with the diagnosis, an accurate evaluation and appropriate management must be executed to have the best outcomes.