Epithelioid osteosarcoma is an uncommon subtype of conventional osteosarcoma that comprised of both typical osteosarcoma component and epithelioid cells. It often occurs in adolescent and children. In here, we report a case of epithelioid osteosarcoma of a 12-year-old Chinese boy. Microscopically, the tumor contains large epithelioid cell with abundant cytoplasm and osteoid forming malignant cells, and partially, the tumor cells arranged in pseudoglandular structures. To our knowledge, it is

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... first report of epithelioid osteosarcoma with pseudo-glandular structure. The epithelioid cells expressed vimentin and epithelial membrane antigen but did not expressed cytokeratin.