Is the solitary papilloma of the bronchus always a benign tumor?

99 pulmonary resections for benign tumors were performed during the period 1967-1978. 4 patients showed bronchial papilloma. Solitary papilloma of the bronchus is one of the rarest benign tumors; the differences of multiple papillomatosis and inflammatory polyp are stressed. Malignant change was observed in 3 of the 4 cases. The 4 patients presented a 2- to 5-year history of hemoptysis episodes and radiographic aspects characterized by intermittent atelectasis. Radical surgery is the only satisfactory therapy; endoscopic removal of the neoplasm is often incomplete and unsatisfactory.