CARTILAGINOUS TUMORS - CORRELATION OF GADOLINIUM-ENHANCED MR IMAGING AND HISTOPATHOLOGIC FINDINGS

Gadolinium-enhanced magnetic resonance (MR) images were correlated with histopathologic findings in patients with cartilaginous tumors. Short repetition time/echo time spin-echo MR images obtained before and after intravenous administration of gadopentetate dimeglumine in 34 patients were evaluated. Twenty-four of 27 low-grade chondrosarcomas showed septal enhancement. The enhancing curvilinear septa consisted of fibrovascular tissue. The nonenhancing areas consisted of paucicellular hyaline cartilage, cystic mucoid tissue, and necrosis. This enhancement pattern and corresponding histopathologic findings were not seen in three benign osteochondromas or four high-grade chondrosarcomas. Inhomogeneous or homogeneous enhancement correlating with highly cellular areas at histopathologic analysis was seen in all high-grade chondrosarcomas. The three osteochondromas showed peripheral enhancement that correlated with fibrovascular tissue covering the non-enhancing cartilage cap. The authors conclude that septal enhancement on MR images after intravenous administration of gadopentetate dimeglumine improves tissue characterization of cartilaginous tumors and may assist in identifying low-grade chondrosarcoma.