Extraskeletal osteogenic sarcoma: a rare entity.

A 25-year-old female presented with a rapidly increasing painful swelling around right lower thigh and knee for the last 5 months with distant metastasis in the form of lung involvement. X-ray of the part showed only soft tissue swelling without any bony involvement. A diagnosis of extraskeletal osteosarcoma was made which was confirmed by immunohistochemistry.