Case. A male aged 38 was admitted, complaining of pain of the right knee joint. The past history and family history were irrelevant. On examination McMurray click and Apley griding test were positive. Tear of the medial meniscus of the right knee joint was found on the arthrogram. Urinalysis, blood count and blood chemistry were normal. After extirpation of meniscus tumor was found in the joint space. Pathologically the tumor was diagnosed nodular tenosynovitis.
