Morphological classification for prediction of malignant transformation in multiple exostoses

AIM: To explore the value of morphological classification in predicting malig - nant transformation in multiple exostoses (ME). PATIENTS AND METHODS: The imaging data of 116 patients (totally 190 tumors) with ME were retrospectively analyzed. All the tumors were pathology confirmed after surgical resection, in - cluding 175 exostoses from 101 patients, and 15 exostotic chondrosarcomas in 15 cases. Based on the ratio of diameter between tumor tip and tumor base (R1), tumors were classified into two types: cauliflower-like tumor (R1 ≥ 1.0) and non- cauliflower-like tumor (R1 < 1.0). In addition, non-cauliflower-like tumors were further classi - fied into two subtypes according to the ratio of tumor height to tumor base diameter: sessile type (R2 < 1.0) and pedunculated type (R2 ≥ 1.0). The relationship between tumor shape and ma - lignant transformation was studied. RESULTS: Of all the 175 exostoses from 101 patients, 27 were cauliflower-like tumors and 148 were non-cauliflower-like tumors. Of all the 15 exostotic chondrosarcomas in 15 cases, most tumors were cauliflower-like ( χ 2 = 38.0075, p < 0.05). Cauliflower-like tumor for the prediction of exostotic chondrosarcoma, the sensibility, speci - ficity, positive predictive value, negative predic - tive value were 86.7%, 84.6%, 32.5%, 98.7%, re - spectively. CONCLUSIONS: Tumor malignant transforma - tion was more common in cauliflower-like tu - mors than in non-cauliflower-like tumors. The morphological classification and preventive re - section of cauliflower-like tumors maybe help - ful in preventing the malignant transformation of ME.