A 67-year-old man with a 40–pack-year history of cigarette smoking with no prior medical history was referred for evaluation of a right upper lobe lung mass. CT showed a 3.0 × 2.5 × 2.3 cm mass with mildly prominent mediastinal and hilar lymphadenopathy. A right thoracotomy with right upper lobectomy and lymphadenectomy was performed. Histologic examination and immunohistochemical stains confirmed a diagnosis of small cell lung carcinoma with adenocarcinoma and squamous cell carcinoma components.