[A case of lung cancer with endometrial metastasis].

A 50-year-old woman was admitted because of chest pain and lumbago. A chest X-ray film showed a 4-cm mass in the left lower lung field. Computed tomography scans revealed a nodule with spicule formation in the left lower lobe, and therefore we strongly suspected lung cancer. Fiberoptic bronchoscopy yielded a diagnosis of adenocarcinoma. However, since she had metrorrhagia we performed an endometrial biopsy. Histologically, the endometrium was similar to the lung lesion, with positive staining for thyroid transcription factor-1 (TTF-1), and lung cancer with endometrial metastasis was therefore diagnosed. Although lung cancer with endometrial metastasis is rare, it should be included in the differential diagnosis in patients with gynecological symptoms such as metrorrhagia.