Synchronous diffuse large B-cell lymphoma of the stomach and small cell lung carcinoma

RATIONALE The synchronous occurrence of lung cancer in patients with gastric neoplasms is relatively uncommon, especially the cases of synchronous coexistence of small cell lung carcinoma and diffuse large B-cell lymphoma of the stomach. PATIENT CONCERNS We encountered a case of synchronous primary small cell lung carcinoma and diffuse large B-cell lymphoma of the stomach. A 63-year-old patient with a 7.5 × 5.09 cm mass in the superior lobe of the right lung diagnosed with small cell lung cancer and synchronous diffuse large B-cell lymphoma of the stomach. DIAGNOSES The diseases were diagnosed by the pathological biopsy and immunohistochemical methods. INTERVENTIONS As the patient received CHOP chemotherapy, pulmonary function deterioraed. Etoposide was added to the chemotherapy. OUTCOMES However, after the first treatment, chest computed tomography showed that the mass in the superior lobe of the right lung had increased to 8.5 × 5.2 cm. LESSONS This report draws attention to the fact that the treatment of synchronous tumors is a challenge.