INTRODUCTION: Solitary respiratory papillomas (SRPs) are considered uncommon yet benign neoplasms of the lower respiratory tract. Most of our understanding stems from single case reports or limited case series.OBJECTIVE: To determine the incidence of solitary SRPs and more accurately describe the localization, distribution of subtypes of solitary SRPs, clinical features, and the risk of malignant transformation. This retrospective report is based on data collected in a busy single-center bronchoscopy practice during a 22-year period.METHODS: Among 36,780 patients who underwent bronchoscopic procedures between 1986 and 2008, we identified 32 patients with SRPs. This patient group was compared with 69 patients with SRPs described in the English literature as case reports, case series, or diagnostic dilemmas.RESULTS: Twenty-three patients were men (male/female ratio of 3:1), and 21 patients were former smokers (65.6%). The mean age of initial presentation in men and women was 56.9 ± 14.3 versus 53.3 ± 14.4 years, respectively. The presenting symptoms included cough in 18 patients (40.6%), hemoptysis in 11 (25%), dyspnea in seven (21.8%), and fever in five patients (15.7%). Two patients with papillomas in the subglottic region had wheezing and were on aerosolized bronchodilator therapy. In one patient, the papilloma was incidentally discovered on a chest computed tomography scan. The histologic analysis of lesions revealed squamous papillomas in 65.6%, a glandular subtype in 18.75%, and a mixed subtype in 15.6%. Malignant transformation was observed in five patients (15.7%). The malignancies consisted of squamous cell carcinoma in two patients, and single cases of small cell lung carcinoma, glandular carcinoma, and low-grade carcinoma.CONCLUSION: In our experience, the estimated incidence of SRPs is 3.95 cases/100,000 patients/yr. SRPs occur more commonly in men (ratio 3:1). Squamous papillomas occur commonly during the fifth decade of life, glandular papillomas predominate in the sixth decade, and the distribution of mixed type papillomas is from the third to the sixth decade of life. Malignant transformation was observed in a minority of patients.