A Radiological Scoring System for Differentiation between Enchondroma and Chondrosarcoma

Simple Summary

Background: It is challenging to differentiate between enchondromas and atypical cartilaginous tumors (ACTs)/chondrosarcomas. Methods: To evaluate the diagnostic usefulness of radiological findings for differentiation between enchondromas and chondrosarcomas, correlations between various radiological findings and final diagnoses were investigated. Based on the correlations, a scoring system combining these findings was developed. Results: In a cohort of 81 patients, periosteal reaction on X-ray, endosteal scalloping and cortical defect on CT, extraskeletal mass, multilobular lesion, abnormal signal in adjacent tissue on MRI, and increased uptake in bone scan and thallium scan was significantly correlated with final diagnoses. Based on the correlations, a radiological scoring system combining radiological findings was developed. In another cohort of 17 patients, the sensitivity, specificity, and accuracy of the radiological score rates for differentiation between enchondromas and chondrosarcomas were 88%, 89%, and 88%, respectively. Conclusion: Comprehensive assessment combining radiological findings is recommended to differentiate between enchondromas and ACTs/chondrosarcomas.

Abstract

Background: It is challenging to differentiate between enchondromas and atypical cartilaginous tumors (ACTs)/chondrosarcomas. In this study, correlations between radiological findings and final diagnosis were investigated in patients with central cartilaginous tumors. Methods: To evaluate the diagnostic usefulness of radiological findings, correlations between various radiological findings and final diagnoses were investigated in a cohort of 81 patients. Furthermore, a new radiological scoring system was developed by combining radiological findings. Results: Periosteal reaction on X-ray (p = 0.025), endosteal scalloping (p = 0.010) and cortical defect (p = 0.002) on CT, extraskeletal mass (p < 0.001), multilobular lesion (p < 0.001), abnormal signal in adjacent tissue (p = 0.004) on MRI, and increased uptake in bone scan (p = 0.002) and thallium scan (p = 0.027) was significantly correlated with final diagnoses. Based on the correlations between each radiological finding and postoperative histological diagnosis, a radiological scoring system combining these findings was developed. In another cohort of 17 patients, the sensitivity, specificity, and accuracy of the radiological score rates for differentiation between enchondromas and ACTs/chondrosarcomas were 88%, 89%, and 88%, respectively (p = 0.003). Conclusion: Radiological assessment with combined radiological findings is recommended to differentiate between enchondromas and ACT/chondrosarcomas.

Radiofrequency ablation of atypical cartilaginous tumors in long bones: a retrospective study

Purpose: To determine the size of the ablation zone after radiofrequency ablation (RFA) of atypical cartilaginous bone tumors (ACT) using temperature-controlled 20 and 30 mm RFA straight non-cooled electrodes.Materials and methods: Sixteen patients with ACT in their long bones, who had undergone a single-session single-application CT-guided temperature-controlled RFA, were included retrospectively in the study. Tumors with a diameter of 10-25 mm were treated with 20 mm electrodes (n = 10), and tumors of 25-35 mm, with 30 mm electrodes (n = 6). The ablated zone was measured after three months on MRI images.Results: All the tumors were within the ablated zone on the 3-month follow-up MRI scan. The mean ablation time with the electrode, at a target temperature of 90 °C, was 7.6 minutes (range 6-10). The median of the largest ablation diameters, on applying the 20 and 30 mm electrodes, were 42 mm (IQR 8.5, range 30-51 mm) and 44.5 mm (IQR 4.5, range 42-63 mm), respectively.Conclusions: All the retrospectively viewed tumors in the long bones of ACT patients treated with RFA were completely ablated. The ablation zone diameters in the bones were larger than expected, when compared to other tissues, such as the liver.