A solitary bronchial papilloma with malignant changes.

We describe a case of solitary papilloma of the bronchus and provide a review of 38 similar cases reported in Japan. A 70-year-old man complained of cough and sputum. Chest X-rays and CT scans revealed atelectasis of the right middle lobe. On bronchoscopy, a polypoid tumor was found at the orifice of the bronchus of the right middle lobe. The tumor was histologically diagnosed as a squamous papilloma with moderate atypia. Because of elevated tumor markers and the reported high incidence of malignant changes in papillomas, the tumor was endoscopically resected by electrosurgical snare. While this procedure resulted in improvement of atelectasis, the chest CT taken subsequently revealed a mass adjacent to the resected polypoid tumor in the middle lobe bronchus. Percutaneous needle biopsy followed by histopathological examination confirmed the tumor to be a squamous cell carcinoma. Only three cases of malignant changes in papillomas have been previously reported in Japan. Electrosurgical snare, which allows the identification of tissue at the tumor base, should be the treatment of choice rather than YAG laser surgery.