Whole-body MRI in assessing malignant transformation in multiple hereditary exostoses and enchondromatosis: audit results and literature review

Abstract

Objective To analyze the results of annual screening using whole-body magnetic resonance imaging (WBMRI) in patients with multiple hereditary exostoses (MHE) and enchondromatosis (EC), and estimate the risk for transformation to chondrosarcoma (CS) in these disorders. Materials and methods A total of 62 patients (57 with MHE and five with EC) screened during a mean follow-up period of 4.6\xa0years (range, 1–10\xa0years) using 253 WBMRIs (median four WBMRIs per patient, range, 1–10) were analyzed retrospectively. The time of WBMRIs was compared with dates for diagnosed CSs. A supplementary literature review was performed focusing on the risk of malignant transformation. Results Ten patients had CS before being enrolled in the screening program, nine with MHE and one with EC. Three asymptomatic CSs were detected by screening; one in a patient with EC and two in patients with MHE, one of whom had CS previously. During the screening period, there was no occurrence of CS not detected by WBMRI in the study group. Histopathologically, the CSs were predominantly grade 1 and were, except for in two patients, located at the truncus, proximal femur, and shoulder girdle. Based on the current material and literature review, the risk of CS seems to be in the range of 2–3.7% for MHE and up to 50% for EC patients. Conclusions MRI may be used as a screening method detecting malignant transformation in MHE and EC patients, but the efficacy has to be confirmed in long-term follow-up studies including cost analysis.