Pleomorphic carcinoma of the lung mimicking synchronous pulmonary adenocarcinoma and small bowel sarcoma

Pulmonary pleomorphic carcinoma is defined as a nonsmall cell lung carcinoma (NSCLC) that contains at least 10% sarcomatoid components. We report a case of pulmonary pleomorphic carcinoma of which only the sarcomatoid component metastasized to the small bowel and adenocarcinoma was identified on percutaneous transthoracic needle biopsy (PTNB). We suggest that if an NSCLC is diagnosed by PTNB and a sarcoma is found at another site, or vice versa, pulmonary pleomorphic carcinoma with a single metastasis should be considered as a differential diagnosis to establish the best effective treatment plan.