A severe systemic presentation of pigmented villonodular synovitis in a child with underlying Chediak-Higashi syndrome.

Pigmented villonodular synovitis (PVNS), a condition of synovial hyperproliferation that mostly affects large joints, is rare in children and conventionally lacks systemic symptoms. This report describes a complex paediatric patient who underwent bone marrow transplantation to control the accelerated phase of the Chediak-Higashi syndrome. Diffuse PVNS developed in one knee 2.