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A 29-year-old male patient was admitted to our clinic with complaints of chest pain and dyspnea. Radiological examination showed a chest wall mass on the left side, which caused rib destruction and massive pleural effusion. The diagnosis was made by transthoracic needle aspiration biopsy, cytological examination of the pleural fluid and pleural biopsy which showed the presence of a malignant round cell tumor. Immunohistochemical assays together with the clinical and radiological findings led to the definite diagnosis of Askin tumor.