Squamous Cell Carcinoma of the Hilar Region of the Lung that was Difficult to Differentiate from Recurrent Esophageal Cancer and Synchronous Multiple Lung Cancer —A Case Report—

Abstract

An 82-year-old man had undergone endoscopic submucosal dissection of esophageal cancer at another medical institution. Chest computed tomography one year later showed a solid mass measuring 3.2 cm in the hilar region of the left lung and a solid node measuring 1.2 cm in S⁶ of the left lung, and he was referred to our hospital. Although the mass in the hilar region was diagnosed as squamous cell carcinoma by bronchoscopic biopsy, whether this was recurrent esophageal cancer or primary lung cancer could not be determined. Therefore, thoracoscopic surgery was performed. The intraoperative rapid diagnosis was squamous cell carcinoma. The mass in the hilar region was an intrapulmonary lesion. Given the stage of progression of the esophageal cancer and the clinical findings, squamous cell carcinoma of the hilar region of the lung was considered highly likely, and left lower lobectomy was therefore performed. The final diagnosis was squamous cell carcinoma of the lower lobe of the left lung, pT3 (pm1) N1M0, Stage III A. Squamous cell carcinoma of the lung is often difficult to differentiate from pulmonary metastasis of esophageal cancer. If oligometastases are present, it should be possible to improve the prognosis by surgical resection, and full consideration should therefore be given to surgery, taking into account the patient's ability to withstand the operation and the degree of invasiveness, even if the differential diagnosis includes metastasis.