Pigmented villonodular synovitis is rare in the younger child, Polyart
icular involvement in this condition, regardless of patient age, is di
stinctly uncommon, The authors describe a case of pigmented villonodul
ar synovitis involving multiple joints in a young boy who also had con
genital anomalies of the genitourinary tract, Although rare, pigmented
villonodular synovitis should be considered in the differential diagn
osis of multiple joint swellings in children with congenital anomalies
.