抄録
The patient, 36-year-old male, first came to our clinic with the complaints of a subcutaneously located huge tumor-like formation of the anterior aspect of his left femur around the knee joint and slight limitation of the affected knee joint motion.
Plain X-ray showed no marked abnormality, but angiography demonstrated a significant hypervascularity at the affected area, CT scan showed the invasion of a tumor-like tissue into the quadriceps muscle.
With such results, the possibility of a malignant soft-tissue tumor could not be excluded.
In the subsequent operation, a huge tumor 15cm by 13cm in diameter, and weightjngd 230g was excised. The tumor had a connection to the joint cavity and had also entered the muscle.
Histological examination showed lamitation of synovial-like cells, hemosiderin deposits and sparse foamy cells, which are the characteristic features of pigmented villonodular synovitis. The most striking pathological findings were the direct invasion of the muscle fiber.
Radiation therapy with a total of 2800rads was initiated post-operatively. Now, 7 months after the operation, the patient is well and without local recurrence, but the significant limitation of joint motion has remained.
