부산대학교 도서관

We report a case of para-articular osteochondrom which occurred in the infrapatellar fat pad.A 52-year-old woman complained of a slow-growing mass with mild pain on anterior aspect of her right knee. Roentgenograms and computed tomography showed three osseous masses which were located in the inflapatellar fat pad. Arthroscopic examination did not reveal any morbid synoviums, but we confirmed the hypertrophy of intraarticular fat pad, and a hard mass inside it. So extraarticular marginal resection was performed. The mass was completely placed in the inflapatellar fat pad, and if was apparently osteochondroma. On microscopic examination, it consisted of normal cartilage cells with areas of ossification. There were not any abnormal cells. Fibrous connective tissue surrounded the lesion, but synovial cells were not found inside. Final diagnosis was para-articular osteochoondroma.In literature, para-articular osteochondroma was a rare disease. And the differential diagnosis between synovial osteochondromatosis and synovial sarcoma is very important.