The patient was a 26-year-old man. During the detailed work-up after the development of pneumonia, he was diagnosed as having a mucoepidermoid carcinoma of the bronchus by transbronchial biopsy and cytology. The smear demonstrated single and loosely aggregated squamous cells, intermediate cells containing a vacuole in their cytoplasm and mucus-producing glandular cells. Histological examination of the resected tissue specimens showed cancer cells spreading discontinuously to the muscle layer. Therefore, careful follow-up was considered necessary even ofter radical operation.
