浸潤性粘液性腺癌と扁平上皮癌からなる肺衝突癌の 1 切除例

Background. We herein report a rare case of primary pulmonary collision cancer comprising invasive mucinous adenocarcinoma (IMA) and squamous cell carcinoma (SCC). Case. A 77-year-old male patient with a chief complaint of coughing was referred to our hospital. Chest computed tomography (CT) revealed a massive infiltrating shadow in the right lower lobe. The tumor was diagnosed as adenocarcinoma by a bronchoscopic examination, and the patient underwent right lower lobectomy and mediastinal dissection. A histopathological examination revealed IMA extensively invading the right lower lobe and SCC encapsulated within the IMA. The patient was diagnosed with primary pulmonary collision cancer comprising IMA and SCC. Conclusion. The preoperative diagnosis of collision cancer of the lung is difficult; therefore, a detailed pathological examination of the resected specimen is important for achieving an accurate pathological diagnosis and considering adjuvant treatment. Although such cases are very rare, it is important not to overlook simultaneous multiple lung cancers, especially those with extensive IMA.