Parosteal osteosarcoma with focal fatty metaplasia: A case r
Parosteal osteosarcoma originates on the surface of long bones. The juxtacortical variety is one of the most common ones and accounts for about 5% of all osteosarcomas.

Published in the journal Radiology Case Reports, the authors report the case of a 34-year-old female patient with a rare variant of parosteal osteosarcoma. Because of the less aggressive biological behavior, it is important to know it, in order to recognize and differentiate it from benign osseous lesions.

A healthy 34-year-old woman was referred to orthopedic oncology clinic for a mass that was identified in her right tibia on radiography after sudden injury of her right lower limb 2 months prior. The patient did not experience any pain or swelling related to the mass. A biopsy performed at another hospital did not reveal any histologic evidence of malignancy.

On physical examination, the patient presented with a hard, poorly circumscribed, painless, and immobile palpable mass at the posterior aspect of the proximal right tibia. The area surrounding the mass was slightly warm, but no changes in the skin were noted. The patient had normal range of motion of the right knee and no abnormal findings on hematologic or biochemical studies.

Radiography of the tibia revealed a well-circumscribed bone-forming lesion associated with the external periosteum of the proximal tibia. Computed tomography showed no medullary involvement and confirmed that the bony mass arose from the periosteum, exhibiting a lower density than the tibial cortex. The tibial cortex appeared to be intact. All findings were compatible with PO. Additionally, 2 areas of fatty density were observed in the osteoid tumor.

Continue to read here:
M●●●j K●●●r and 1 others like this