Pigmented villo-nodular synovitis: bone involvement of the fingers.

Pigmented villo-nodular synovitis may occur in either diffuse or nodular form. In the latter the fingers are the commonest site to be involved. The disease is rare, and in only 15% is there bone involvement. Two cases showing bone involvement of the fingers are presented. One of the cases (Case 2) adds radiological support to the theory of Scott (1968), based on pathological studies, that suggested that the bone changes are due to invasion by the villo-nodular tissue through and along the nutrient foramina. The site of these bone changes appears sufficiently typical to be a radiological diagnostic aid. The differential diagnosis of the radiological appearances of the disease in the digits is discussed.