Pigmented villonodular synovitis. Diffuse and localized forms in two children

Pigmented villonodular synovitis (PVS) is characterized by a locally aggres sive synovial proliferation that engenders progressive destruction of carti lage and bone. Two cases, a diffuse and a localized form, are reported, Case report. - 1) A 9.9-year-old boy followed up for a popliteal cyst prese nted with chronic arthritis of the left knee. Aspiration yielded a bloody s ynovial fluid. MRI showed a heterogeneous synovial process with decreased s ignal in both T1- and T2-weighted images. The diagnosis of PVS was made on histology of an excisional biopsy. A complete open synovectomy was then per formed. 2) A 13.8-year-old boy had a palpable mass on the internal side of the right patellofemoral joint. MRI showed a heterogenous mass with areas o f hypointensity on all spin echo sequences corresponding to hemosiderin dep osits suggestive of PVS. Surgical excision of a reddish-brown circumscribed lesion was performed. Diagnosis of PVS was made at surgery and confirmed b y histologic examination. Conclusion. - PVS diagnosis is frequently delayed due to nonspecific sympto ms. Bloody fluid aspiration and MRI are valuable tools for early diagnosis. Treatment is surgical: extensive synovectomy for the diffuse form, excisio n of the lesion for the localized form. (C) 2001 Editions scientifiques et medicales Elsevier SAS.