Chondroblastoma of extra-craniofacial bones: Clinicopathological analyses of 103 cases

We elucidated clinicopathological characteristics of chondroblastoma (CB) in Japan, and reliable clinicopathologic parameters predicting local recurrence and/or metastasis. Clinicopathological profiles of 103 CB (80 male, 23 female) in extra-craniofacial bones were retrieved. Numerical scoring of nine pathological and five radiological features was statistically analyzed to determine prognostic significance. Age ranged 8–61 years (average 19.6 years). Frequently involved sites were femur, tibia, calcaneus, patella and humerus. Radiologically, tumors were 2–80 mm (average 31.1 mm) in size. Marginal sclerosis and calcification were common. Histologically, pink cartilage, mitoses, and chicken-wire calcification were often seen. Within a follow-up period [2–260 months (average 53.5 months)], the local recurrence rate was 15.5%. No patient had metastasis. Recurrence was most frequently observed at the femur. By log-rank analysis, only cyst formation in images was significant for predicting recurrence free survival (RFS). By Cox hazard analysis with representative clinico-radiological and pathological features, only age (≥16 years) and cyst formation were significant predictors for RFS. Pathological features were not significant in both uni- and multivariate analyses.