Synchronous Primary Pleural Mucosa-Associated Lymphoid Tissue Lymphoma and Pulmonary Squamous Cell Carcinoma in a Patient With Asbestos Exposure: A Case Report

Primary pleural extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) is extremely rare. We report the case of a Japanese man in his 70s who had a history of asbestos exposure and known bilateral pleural plaques and presented with dyspnea. Imaging studies revealed a pulmonary mass in the left lower lobe, and a biopsy confirmed squamous cell carcinoma of the lung. Positron emission tomography-computed tomography (PET-CT) incidentally revealed increased radiotracer uptake in the pleura between the third and fourth left ribs. The pleural mass was diagnosed as primary pleural MALT lymphoma on biopsy. To the best of our knowledge, this is the first reported case of the synchronous occurrence of primary pleural MALT lymphoma and pulmonary squamous cell carcinoma in a patient with a documented history of asbestos exposure.