[A suspected case of T0N1M0 small cell carcinoma of the lung].

A 51-year-old man was admitted to our hospital with a chief complaint of cough. His chest X-ray and CT scan revealed enlargement of a left hilar lymph node. However, no primary lesion was apparent in the rest of the lung. Bronchofiberscopic findings were essentially normal. At surgery the mass was determined to be an enlarged lymph node (No. 11). No apparent malignant lesion was identified in the lung. Postoperative pathological examination showed small cell carcinoma in a part of the No. 11 lymph node. Despite a thorough systemic examination, no primary foci were detected. We have been following up this patient with chemotherapy for the approximately 2 year period since the operation, but no primary lesions have been detected as yet. Therefore, we speculate that this patient is a very rare case of primary unknown T0N1M0 lung cancer.