Pigmented villonodular synovitis (PVNS) is an unusual condition of the lining inside the knee joint, where the synovial cells are abnormally laden with a brown pigment.

Pigmented villonodular synovitis low mag
Microscopic view of a piece of tissue showing the blobs of darker pigmentation between the pinker but overgrown synovial tissue.

Dr Sheila StroverĀ (Editor)
BSc (Hons), MB BCh, MBA

See biography...