Localized pigmented villonodular synovitis of posterior compartment of the knee.

Pigmented villonodular synovitis (PVNS) is an uncommon entity involving articular or extra-articular tissues and maybe localized or diffuse in extent. The knee is by far the commonest joint to get involved. Localized PVNS of the knee can occur in any location but its confinement to the posterior compartment is infrequent.