DIAGNOSTIC FEATURES OF DIFFUSE PIGMENTED VILLONODULAR SYNOVITIS OF THE KNEE

Twenty-five cases of diffuse pigmented villonodular synovitis of the k nee in 23 patients were reviewed to identify characteristic clinical p resentations and histologic findings. All cases met strict histologic criteria for diagnosis. Clinical presentation consisted of insidious a nd progressive symptoms of significant joint swelling with discomfort, but not isolated pain. On physical examination, a suprapatellar pouch that was markedly distended by either effusion, synovial masses, or b oth, and a slight flexion posture were the most consistent findings. A spiration to detect a bloody effusion was unreliable as a diagnostic t ool. Pigmentation was absent in 16% of the gross specimens. Histologic ally, iron deposition was present in all cases and to a moderate or ma rked degree in most. Fibrosis, hyalinization, and chronic inflammatory changes were present in most, but to a lesser degree. No patient had gross, histologic, or treatment follow-up findings consistent with neo plasia. Attempts to predict clinical outcome based on histologic findi ngs mere unrewarding.