A Case of Tracheal Mucosa-associated Lymphoid Tissue Lymphoma Diagnosed by Endobronchial Ultrasound-guided Miniforceps Biopsy

Tracheal mucosa-associated lymphoid tissue (MALT) lymphoma is rare, and its diagnosis can be challenging. We herein report the case of a 70-year-old woman with a history of right upper lobectomy and lymph node dissection for lung adenocarcinoma (pT2aN0M0, stage IB) performed 6 years prior to presentation. Follow-up chest computed tomography incidentally revealed a tracheal nodule. Bronchoscopy revealed a smooth, elevated lesion. An initial biopsy using endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) was inconclusive. Therefore, we performed an endobronchial ultrasound-guided miniforceps biopsy (EBUS-MFB), which yielded sufficient tissue for diagnosis. Histopathological examination revealed diffuse infiltration of centrocyte-like cells, consistent with a low-grade B-cell lymphoma such as MALT lymphoma. No other organ involvement was found, and a diagnosis of tracheal MALT lymphoma was made. EBUS-MFB is a useful and safe technique for diagnosing rare tracheal lesions, such as MALT lymphoma, when EBUS-TBNA results are inconclusive.