Synovial chondromatosis of Hoffa's body is uncommon. Recurrences usually result from incomplete removal of the loose bodies or diseased synovium at the initial surgery. We report a patient with synovial chondromatosis localized into the Hoffa's body who presented with anterior knee pain and mechanical symptoms. At the first arthroscopy, all pathological tissue was removed. At 1-year follow-up, clinical and radiographic examinations were normal. Symptoms recurred at 3 years, when a bony mass in the Hoffa's body was evident on MRI. The mass was removed through a mini-arthrotomy. Histology excluded malignancy. At 10-year follow-up, the patient remained free of symptoms. Synovial chondromatosis can occur with unusual patterns of recurrence. The growth of a large size mass confined to fat pad without intra-articular involvement does not allow to exclude the diagnosis of recurrent synovial chondromatosis.
