Primary tracheal mucosa-associated lymphoid tissue lymphoma accompanying lung cancer. Common tumorigenesis or coincidental coexistence?

We report a 67-year-old patient with coexistent tracheal non-Hodgkin's lymphoma and lung cancer the first case, to our knowledge, of this concomitant incidence in the literature. Chest radiography showed a mass in the right lung and pulmonary fibrosis. Biopsy of the unanticipated tracheal irregularity revealed non-Hodgkin's lymphoma, compatible with mucosa-associated lymphoid tissue lymphoma. After right upper lobectomy, chemotherapy for non-Hodgkin's lymphoma was conducted, but the patient died 11 months postoperatively of pulmonary fibrosis. Pulmonary fibrosis was suspected of having progressed from drug-induced pneumonitis caused by anticancer drugs. A common tumorigenetic factor may thus exist between tracheobronchial mucosa-associated lymphoid tissue lymphoma and lung cancer.