HighlightsThe giant cell tumor is a benign, primary skeletal neoplasm with variable biologic aggressiveness.A coexistence with hereditary multiple exostosis with expression of EXT-1 is very rare.BCL-2 gene is expressed only in malignant transformation of the giant cell tumor.The correlation between giant cell tumor and hereditary multiple exostosis is still not clearly determined.The case revealed giant cell tumor in hereditary multiple exostosis with positive EXT-1 without BCL-2 expression.