We report a case of pulmonary basaloid carcinoma. A 73-year-old man was found in radiological and transbronchial endoscopic exami-nation to have a 40×30mm whitish tumor filling the right bronchus. Bronchial brushing cytology showed numerous tumor cells with a background of massive necrosis. Tumor cells had a hyperchromatic. rather uniform oval nucleus and scanty cytoplasm-cellular features resembling those of small-cell carcinoma. Histological examination showed a basaloid carcinoma with distinctive hyalinized stroma. Among differential diagnoses, the distinction from small cell carcinoma is most important because of the difference in their biological behavior and therapy.
