Polyarticular pigmented villonodular synovitis in children: evidence for a genetic contribution.

Pigmented villonodular synovitis rarely occurs in multiple joints, and only once has been noted in siblings. We identified this disorder in 2 generations and found evidence for its presence in a third. It occurred in 2 sibling children at multiple sites. All affected individuals also had a rare autosomal dominant disorder, the multiple lentigines syndrome. Among the developmental abnormalities in this kindred were fibrous dysplasia, hypertelorism, pectus excavatum, high arched palate, and primary lymphedema. The etiology of pigmented villonodular synovitis is uncertain, and suggested causes include trauma, inflammation, neoplasia, and repeated hemorrhage. Our observations suggest genetic factors might also be important in the development of pigmented villonodular synovitis.