Misdiagnosis of chordoma: A case report and a review of the literature.

The present study aimed to investigate the clinicopathological features and diagnostic criteria for differentiating between chordoma and chordoid meningioma. A case of chordoma was retrospectively analyzed using clinical, radiographic, histological and immunohistochemical data, alongside a literature review. A 59-year-old male patient was admitted with headaches and dizziness persisting for 2 months without any obvious precipitating factors. The patient underwent two intracranial tumor resections between March 2022 and December 2023. The pathology report from the first surgery indicated that the tumor was composed of cords of epithelioid cells with vacuolated cytoplasm embedded in a basophilic stroma. Immunohistochemical analysis showed positivity for cytokeratin, vimentin, epithelial membrane antigen, synaptophysin, cytokeratin 8/18 and E-cadherin, with a Ki-67 proliferation index of 3%. Progesterone receptor, D2-40, glial fibrillary acidic protein, S100 and SOX10 staining were negative. Based on the pathology and immunohistochemical findings, the diagnosis was determined to be a chordoma-like meningioma (World Health Organization Grade 2). The pathology report from the second surgery revealed a tumor composed of cords and isolated epithelioid cells with intracytoplasmic vacuoles within a myxoid matrix. However, immunohistochemical analysis indicated positivity for Brachyury, leading to a diagnosis of chordoma. In conclusion, the histological morphology of chordoma is similar to that of chordoid meningioma and lacks clinical specificity. Immunohistochemical staining of tumor markers assists in both the diagnosis and differential diagnosis. Currently, treatment for chordoma and choroid mengioma primarily focuses on surgical resection, which is associated with high rates of relapse. The differential diagnosis predominantly influences the postoperative treatment strategy.