Small-cell lung cancer arising after chemotherapy for a patient with lymphoma of pulmonary mucosa-associated lymphoid tissue-a case report.

A 76-year-old woman was admitted to our hospital with infiltrations evident in the right lower lobe on chest computed tomography. Bronchoscopic biopsy showed lymphoma of mucosa-associated lymphoid tissue (MALT). Lymphoma of the pulmonary MALT became enlarged at 8 months after diagnosis and dyspnea developed. Four courses of chemotherapy(rituximab+ cladribine)resulted in a partial response. However, 14 months after the chemotherapy, she developed multiple lung and liver tumors accompanied by disseminated intravascular coagulation syndrome. A histological examination of bone marrow aspiration showed small cell carcinoma. We administered one course of carboplatin and etoposide, but bone marrow suppression was so severe that further chemotherapy was precluded. To our knowledge, this is a rare case of small cell lung cancer arising from the treatment of lymphoma of pulmonary MALT.