Pigmented Villonodular Synovitis (PVNS): More Prevalent Than Previously Reported.
Timothy M D'Alfonso, Michael J Klein, Edward F DiCarlo. Weill Cornell Medical College, New York, NY; Hospital for Special Surgery, New York, NY
Background: Pigmented villonodular synovitis (PVNS) is a benign but locally aggressive tumor affecting the synovium, tendon sheaths, and bursae. In the literature, PVNS is regarded as a rare process with a reported incidence of 1.8 cases per million (0.0000018%) in the general population. Based upon our experience at a large referral center, we believe that PVNS is more common, particularly in the knee, than has been reported, prompting this current study. Here we report the results of a retrospective analysis of all cases of PVNS diagnosed at our institution over a 15 year period.
Design: All cases of PVNS identified from our files from 1995 to 2010 were included in the study. Tumors were classified as “incidental” if they were discovered in specimens from procedures performed on patients for a pre-operative diagnosis other than PVNS, e.g. degenerative joint disease (DJD), or if the pathologist had specifically documented the tumor as incidental in the report. Estimated prevalence of PVNS in the knee was calculated by dividing the number of incidental cases of PVNS by the total number of knee replacements performed over the same time period.
Results: 32,206 patients underwent total knee replacement surgery during the study period. 317 of these patients were diagnosed with PVNS, with PVNS an incidental finding in 110 of these cases. From this information, we estimate the prevalence of PVNS in patients undergoing total knee replacement to be between 0.3 and 0.9%.
Conclusions: In prior studies, the incidence of PVNS was established based on cases in which PVNS was the targeted lesion. In our study we calculated prevalence based on incidental PVNS discovered in patients with unrelated knee disease, predominantly DJD. We found PVNS to be far more prevalent in patients undergoing surgery for reasons other than PVNS, suggesting that the actual prevalence of PVNS in the general population is likely significantly higher than what has been previously reported.
Category: Bone & Soft Tissue
Tuesday, March 1, 2011 9:30 AM
Poster Session III # 15, Tuesday Morning