Rare and Elusive: The Challenges of Bronchoscopically Diagnosing Pulmonary Mucosa-Associated Lymphoid Tissue Lymphoma

Primary pulmonary lymphomas (PPLs) are rare clinical entities representing 0.5%-1% of all pulmonary neoplasms, of which mucosa-associated lymphoid tissue (MALT) lymphoma is the most common type (80%). PPLs are traditionally considered challenging to diagnose bronchoscopically given the rarity of these entities, small sample sizes, and the ancillary testing often required to adequately differentiate them from benign intraparenchymal lymph nodes. Here, we report three cases of pulmonary MALT lymphomas. In two cases, the patients presented with pulmonary nodules and were diagnosed by robotic-assisted bronchoscopy following prior nondiagnostic biopsy attempts. The third patient presented with distal tracheal thickening, where flexible bronchoscopy revealed a particularly rare case of MALT lymphoma with endobronchial involvement.