An Autopsy Case of Lepidic Pulmonary Metastasis from Cholangiocarcinoma.

We herein report the first case of pulmonary metastasis with lepidic growth that originated from cholangiocarcinoma. A 77-year-old man was admitted to our hospital due to exertional dyspnea and liver dysfunction. Computed tomography showed widespread infiltration and a ground-glass opacity in the lung and dilation of the intrahepatic bile duct. The pulmonary lesion progressed rapidly, and the patient died of respiratory failure. Cholangiocarcinoma and lepidic pulmonary metastasis were pathologically diagnosed by an autopsy. Lepidic pulmonary growth is an atypical pattern of metastasis, and immunopathological staining is useful to distinguish pulmonary metastasis from extrapulmonary cancer and primary pulmonary adenocarcinoma.