PRIMARY SYNOVIAL CHONDROMATOSIS - A CLINICOPATHOLOGICAL REVIEW AND ASSESSMENT OF MALIGNANT POTENTIAL

This is a clinicopathologic review of 53 cases of primary synovial cho ndromatosis covering a period of 30 years. The average age at presenta tion was 41 years (range, 17 to 64 years) with a male/female preponder ance of 1.8:1. The condition was always monarticular, the most common site being the knee joint (70%) followed dy the hip (20%). Degenerativ e joint disease was well established in three patients (5%), all occur ring in the hip. Nine patients suffered recurrences (15%), including t hree that became malignant. There was no relationship between the age and site of the lesion, nor between the degree of cellularity of the c artilage and age or site. However, there was an association between ce llularity of the cartilage and the extent of calcification and ossific ation-highly cellular lesions were poorly calcified and ossified, but heavily calcified lesions were usually of relatively low cellularity. There was no relationship between extent of calcification and ossifica tion and the age of the patient. Three patients Suffered malignant cha nge representing a relative risk of 5%, much higher than that quoted i n other series. This suggests that primary synovial chondromatosis has a significant potential for malignant change. Copyright (C) 1998 by W .B. Saunders Company.