PIGMENTED VILLONODULAR SYNOVITIS

SAGITTAL PDFS IMAGE SHOWING LARGE SYNOVIAL EFFUSION WITH SYNOVIAL THICKENING

SAGITTAL PDFS IMAGE SHOWING MULTIPLE NODULAR MASSES IN THE JOINT SPACE POSTERIORLY SHOWING HYPOINTENSE FOCI AND HYPOINTENSE RIM(  HEMOSIDERIN)

SAGITTAL PDFS IMAGE SHOWING SIMILAR NODULAR MASSES IN HOFFA'S FAT PAD.

STIR CORONAL IMAGE SHOWING HYPOINTENSE NODULAR SYNOVIAL THICKENING ON THE LEFT SIDE

AXIAL GRE IMAGE SHOWING "BLOOMING" OF NODULES/NODULAR SYNOVIAL THICKENING

AXIAL GRE IMAGE SHOWING BLOOMING OF NODULES

AXIAL GRE IMAGE SHOWING SIGNIFICANT BLOOMING OF SYNOVIAL BASED NODULES SUGGESTIVE OF HEMOSIDERIN CONTENT

SAGITTAL T1 IMAGE SHOWING ALMOST ISOINTENSE NODULES

49 year old patient presents with joint swelling and pain.
MRI reveals large synovial effusion with synovial thickening. There are multiple nodules within the joint which show hypointense areas on fluid sensitive sequences and bloom significantly on GRE suggestive of hemosiderin content.

PIGMENTED VILLONODULAR SYNOVITIS: 

• Benign, locally aggressive lesion
• Characterised by an abnormal synovial lining which is prone to hemorrhage with minor trauma resulting in repeated hemorrhagic effusions and iron deposition in the synovium and nodules
• There may be bony erosions and subchondral cysts with nodular proliferaition of synovium
• Patient presents with an insidious onset of painful joint swelling. Sometimes, torsion of nodules may cause sudden sharp rise in pain.
• Usually mono-articular
• There is a wide age range of presentation but commonest being 30-40 years.
• If untreated, repeated bleeding and synovial proliferation with erosions may lead to joint destruction. 
• GRE is most important sequence in MRI for its diagnosis as it elicits characteristic "blooming" of lesions.

DIFFERENTIALS:

INTRA-ARTICULAR NODULAR SYNOVITIS

•  May be completely identical to PVNS on MRI
• Generally show less effusion  and less hemosiderin than PVNS

 SYNOVIAL CHONDROMATOSIS

• generally loose bodies are seen on radiographs
• Sometimes conglomerate los signal masses on MRI in the synovium may be confused with PVNS but do not bloom on GRE

HEMOPHILIAC ATHROPATHY:

• Effusion with synovial proliferation
• Blooms on GRE
• However, morphologyis different with overgrown epiphyses/ metaphyses
• Also is often familial

REFERENCE:
Manaster BJ:Pigmented Villonodular synovitis( PVNS). Diagnostic Imaging Musculoskeletal: Non-Traumatic Disease: First Edition.Amirsys:I-134,2010.