Histopathologic Differentiation between Enchondroma and Well-differentiated Chondrosarcoma: Evaluating the Efficacy of Diagnostic Histologic Structures

BACKGROUND AND AIMS: Well-differentiated chondrosarcoma and enchondroma are similar in histopathologic aspects; therefore, special methods should be used to make a distinction between these benign and malignant tumors. The aim of this study was to evaluate the efficacy of a histopathologic method in the long-term follow-up for differentiating these lesions. MATERIALS AND METHODS: The medical records of patients with histopathologic diagnosis of chondrosarcoma and en-chondroma were retrieved from the Institute of Cancer, Department of Pathology from 1981 to 2007 in this retrospective study. A total of 14 patients with chondrosarcoma and 7 patients with enchondroma were included. Tumor lobulation pat-tern and fibrous tissue around the lesions were used for histopathologic differentiation between well-differentiated chon-drosarcoma and enchondroma. Method accuracy was evaluated by tumor recurrence in the long-term follow-up. RESULTS: In the well-differentiated chondrosarcoma group, the follow-up period was 97 months. All the patients (100%) experienced recurrence. In the enchondroma group, the follow-up period was 129 months. There was no recurrence in this group. CONCLUSION: Lobulation pattern and fibrous tissue formation around the tumor can be an effective and helpful indicator for histopathologic differentiation between enchondroma and well-differentiated chondrosarcoma.