Pigmented villonodular synovitis as a differential of subchondral cysts

الملخص EN

Pigmented villonodular synovitis (PVNS) is a rare disease which commonly involves the knee joint.

It can be seen in association with bursa, tendon sheath or intra-articular; it could be localized or diffused form.

Subchondral cysts, giant cell tumor, and geode degenerative cysts as a differential of chronic erosive form could be diagnosed by plain radiography.

A twenty-year-old female presented with one year history of right knee pain and mild swelling.

Plain radiography and CT revealed an initial diagnosis of benign-looking lytic subchondral lesions and subchondral cysts were suspected.

MRI raised the possibility of PVNS.

Arthroscopic resection was performed.

The diagnosis was confirmed as PVNS by histopathological examination.

The patient is currently in good condition.

A multi-disciplinary team decided to proceed with radio-synovectomy to prevent a recurrence.