A 67-year-old woman presents with fatigue, cough, and dyspnea. She reports intermittent low-grade fever and an unexplained 15-lb weight loss in the past 2 months. She has a 30-year history of smoking but quit 10 years ago. Physical exam reveals diminished breath sounds and slight hepatomegaly. The patient appears pale and cachectic. Chest radiography shows an ill-defined mass in the right upper lobe. CT reveals a 4-cm spiculated mass. Histologic findings show prominent nucleoli and focal necrosis, with no evidence of keratinization or gland formation.