A Case of Tracheal Stenosis Caused by Mediastinal Metastasis of Gastric Cancer Mimicking Fibrosing Mediastinitis

Abstract

Background. When tracheal stenosis developed in a patient who had undergone total gastrectomy for gastric cancer, the presence of inflammatory lesions with fibrosis around the trachea required the differentiation of fibrosing mediastinitis from mediastinal metastasis. Case Presentation. Five years after total gastrectomy, tracheal stenosis was observed in a 67-year-old man being followed at our institution. The previous year, computed tomography had shown an area of soft tissue density around the trachea, and the density of that soft tissue had now further increased. Fibrosing mediastinitis was suspected, so endobronchial ultrasound-guided transbronchial fine-needle aspiration (EBUS-TBNA) was performed to sample the anterior tracheal tissue. When a sufficient specimen could not be obtained, an ultrasound-guided needle biopsy with the head tilted to expose the neck was performed. That specimen revealed a fragment of cancer tissue with a ductal structure, resulting in a diagnosis of metastasis to the mediastinum, accompanied by an inflammatory fibrotic lesion. A reexamination of the specimen from the gastrectomy confirmed HER2 positivity of the gastric cancer, and treatment with trastuzumab and capecitabine was started. The tracheal stenosis subsequently improved. Conclusion. The need to differentiate mediastinal metastasis from fibrosing mediastinitis rarely occurs. It is necessary to select a biopsy method that allows for sufficient sample collection based on imaging findings.