What benign synovial tumor can cause synovial calcifications?
Primary synovial osteochondromatosis is a benign condition occurring most commonly in patients aged 30 to 50 years where an inflamed synovium undergoes metaplasia resulting in cartilage nodules that can undergo calcification and ossification. The calcifications can break free as loose bodies into the joint space leading to locking and articular cartilage damage causing osteoarthritis. It most commonly occurs in the knee, hip, or shoulder, but any joint can be involved. Radiographs demonstrate multiple calcific densities looking like “popcorn”. The etiology is unknown. Treatment is symptomatic but often requires surgical removal of the loose bodies and synovectomy. Incomplete synovectomy can result in disease recurrence.