Primary synovial osteochondromatosis of the surapatellar pouch of knee. Correlation of imaging features with surgical findings.

A 31 years old female presented with swelling and pain above the right knee for three years. On examination, there was a tender swelling over the right knee more pronounced over the suprapatellar region. Plain X-ray, US, CT scan and MRI of the knee were suggestive of Primary synovial osteochondromatosis (PSC) of the suprapatellar pouch. Patient underwent total synovectomy and the diagnosis of synovial osteochondromatosis was confirmed histopathologically. Recognizing the imaging appearances of PSC is important to improve patient management.