Pleuric presentation of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue: a case report and a review of the literature.

A primary pleural marginal zone B cell lymphoma of mucosa-associated lymphoid tissue (MALT) is a very rare eventuality. Here, we report a rare case of MALT lymphoma arising in the pleura and update the literature on this topic. A 74-year-old female was hospitalized for persistent cough and weakness. A chest radiograph and total-body CT scan showed only large right-sided pleural effusion, and the coexistence of pleural thickening. Video-assisted thoracoscopic exploration and a talc pleurodesis were performed and microscopic and immunohistochemical findings showed that the tumor was a pleural MALT lymphoma. The patient received immunotherapy with Rituximab and obtained a good response that lasted 2 years. To the best of our knowledge, only seven cases of primary pleural MALT lymphoma have been documented until recently, mostly from Japan with a mean age for all patients of 60.5 years. The pathogenesis of MALT lymphomas remains unclear, although a possible chronic antigenic stimulation by microbial pathogens and/or autoantigens has been hypothesized. Surgical resection was performed in most cases, and some patients received postoperative chemotherapy or immunotherapy. The clinicopathologic characteristics and management of this extremely rare disease are also discussed.