Pulmonary B-cell non-Hodgkin's lymphoma associated with autoimmune disorders: a clinicopathological review of six cases.

Because pulmonary B-cell non-Hodgkin's lymphomas are now thought to arise in bronchial mucosa-associated lymphoid tissue (MALT), 45 patients with pulmonary B-cell lymphomas were reviewed to look for aetiological factors in the lung. It was found that six of the 45 lymphomas arose in patients with systemic autoimmune disease, which in three patients involved the lung. These three patients all had cryptogenic fibrosing alveolitis treated with long-term immunosuppressive therapy. Five of the six lymphomas were high grade and one was low grade. The association of pulmonary lymphomas with autoimmune interstitial lung disease is consistent with associations between autoimmune diseases and lymphomas presenting at other mucosal sites, and lends weight to the hypothesis that formation of bronchial mucosa-associated lymphoid tissue precedes the development of lymphoma.