High-Grade Chondrosarcoma Arising from Synovial Chondromatosis: Case Report and Review of the Literature
Abstract
Synovial chondromatosis (SC) is a rare, locally aggressive, benign tumor that presents as a lobulated bundle of hyaline cartilaginous nodules in the joint spaces, sub-synovial tissue, or tenosynovium. SC mainly affects large joints, particularly the knee joint. Although malignant transformation of SC to chondrosarcoma (CS) is possible, only a few cases have been reported. Radiologically, SC can present as an aggressive benign tumor, and adequate tissue sampling is essential for a proper diagnosis in cases of malignant transformation. Insufficient tissue biopsy sampling may miss the transformed malignant areas, resulting in a diagnosis of a benign cartilaginous tumor and inadequate patient management. We report a case of intermediate to high-grade chondrosarcoma occurring in the background of synovial chondromatosis. We also review the current literature on SC and CS and discuss the pathophysiology of the malignant transformation.