Unusual aspects of synovial chondromatosis of the elbow.

A 60-year-old man suffered locally from a rather aggressive chondromatosis of the elbow. Clinically the presentation was rather uncommon, with some radiological aspects (juxta-articular bone rarefaction) differing from those of ordinary chondromatosis. Neither the pathologist nor the radiologist recognized signs of malignancy. Regional osteoporosis, although rarely described in synovial chondromatosis, was considered as the diagnosis in this patient, but a low grade primitive chondrosarcoma must be sought in such cases.