PIGMENTED VILLONODULAR SYNOVITIS (PVNS)

Note the synovial proliferation with hemosiderin deposition in the right tibiotalar joint (hypointense on T1 and T2 WI)  with large subchondral bone erosions (PD). The articular cartilage appears eroded and the adjacent cortex is irregular. There is extensive marrow edema in the distal tibia and the talus.

PVNS is characterized by slowly progressive, exuberant, benign proliferation of synovial tissue, usually involving a single joint .

Age : 3rd decade, Females>male

Locations : knee ,hip , ankle , wrist , hand , foot

X – rays – joint space narrowing erosions with sclerotic margins [ apple core deformity in hip joint ] subchondral cysts  , smooth ,  well–defined cortical excavations  which may give the bone a “bubbly” appearance.

Intraarticular effusions , dense lobulated soft tissues and displacement of fascial planes

 CT – To define extrinsic bone erosions. No post – contrast enhancement.

Angiogram – contrast puddling and tumour blush.

MRI – Low signal intensity of synovial lining on T1and T2 WI . This is due to hemosiderin deposits.

Joint edema – hypointense on T1 and hyperintense on T2 WI . Marrow edema .

MRI is modality of choice for diagnosis of this condition .

USG guided biopsy  was performed. Dark red , blood-tinged fluid mixed with few solid components was obtained .