Radiological features of the intracranial extra-skeletal mesenchymal chondrosarcoma

Background: Mesenchymal chondrosarcomas are the most malignant form of chondrosarcomas. They have mostly affected bones. Rarely, these tumors can be intracranial extraskeletal (IEMC) that originates from the meninges or parenchyma. Methods and Materials: We presented two IEMC patients who were treated at our institutions and followed up for the long-term. To understand the radiological features of IEMC, we conducted a systematic literature review for previously reported series and cases of IEMCs. Results: We surgically treated two young males with IEMC initially diagnosed at their age of 18 and 20 years. The patients initially treated with gross total resection (GTR) and GTR followed by radiotherapy, and followed-up for 218 and 73 months, respectively. With both patients, we obtained 83 reported IEMC patients from the literature. Among them, only 30 cases were reported with their radiological MRI details. The mean age of the reported cases was 24.5±16.0 years (2 months–71 years). Female predominance was 54.2%. The mean progression-free and overall survivals were 27.9 and 39.0 months, respectively. Most IEMCs showed a partially calcified mass on roentgenography and a highly vascular mass on angiography. On T1WIs, IEMCs almost show hypo- to isointensity and intense heterogeneous enhancement after administering a contrast substance. On T2WIs, IEMCs show iso- to hyperintensity. Conclusions: IEMCs usually show dural attachment without a net dural tail sign and a well-identified brimmed vascular nodule on TOF-MRA. This nodule appears as a prominent blooming on SWI. TOF-MRA and SWI images can help in the radiological diagnosis of IEMCs.