Abstract
Background. Pleomorphic carcinoma with choriocarcinomatous differentiation is rare, and is considered to be a high-grade malignant lung tumor that can lead to early metastasis and recurrence. Case. A 39-year-old woman was admitted to our hospital because of anemia. Upon examination, we detected a hemorrhagic duodenal tumor and a tumor in the right lower lobe of the lung. Based on the results of endoscopic biopsy, which obtained poorly differentiated carcinoma from both tumors, we ascertained that this case represented primary lung cancer with a metastatic duodenal tumor. We performed surgical resection of both the duodenal and the lung tumors. Heterogeneous tumor tissue, including choriocarcinomatous, giant cell, and large cell-like features, was observed microscopically in the resected specimens, which stained immunohistochemically for human chorionic gonadotropin (hCG). The pathological diagnosis was "pleomorphic carcinoma with choriocarcinomatous differentiation, pT2N0M1 stage IV". Conclusion. We treated a rare case of hCG-producing pleomorphic carcinoma with choriocarcinomatous differentiation that was discovered after hemorrhage of a metastatic duodenal tumor. The usefulness of surgical resection for primary and/or metastatic lesions of stage IV lung cancer is not sufficiently well established. However, it could be an effective treatment for some patients.
