[Laryngeal Papillomatosis: A Statistical Analysis of 60 Cases].

Laryngeal papillomatosis is the most common benign neoplasm of the larynx. Juvenile onset laryngeal papillomatosis tends to recur. In patients with adult onset laryngeal papillomatosis, laryngeal cancer rarely develops. This paper reports a clinical analysis of 60 patients with laryngeal papillomatosis who were treated at our clinic between January 1971 and September 2009. We analyzed the sex ratio, age at the onset of papilloma, type of developing papilloma (single or multiple type), site of developing papilloma, recurrence rate, and therapeutic modalities. Furthermore, the clinical characteristics of the patients with malignant transformation were examined. The patients were classified according to their age at the onset of the papilloma and the type of developing papilloma. The patients were grouped into a juvenile-onset group and an adult-onset group according to their age at the onset of the papilloma. They were also classified into single-type or multiple-type according to whether the initial papilloma appeared singly or multiply. The male to female sex ratios were 1.2 in the juvenile-onset group and 5.1 in the adult-onset group. Among the patients who developed papilloma at an age of under 10 years old, most of the juvenile cases had experienced onset by 4 years of age. Furthermore, the frequency of multiple-type papilloma was significantly higher in the juvenile-onset group, compared with the adult-onset group. The vocal fold was the most frequent site of the papilloma. The recurrence rate in the juvenile-onset group was significantly higher than that of the adult-onset group. A stratified analysis according to the type of papilloma occurrence, however, showed no significant difference in recurrences between the juvenile-onset and adult-onset groups. A stratified analysis according to the age at the onset of papilloma showed that the recurrence rate of multiple-type papilloma was significantly higher than that of single-type papilloma in the adult-onset group. Among multiple therapeutic modalities, vaporization by carbon dioxide laser was the most frequently used. Adjuvant therapy was performed in 6 cases who suffered from multiple relapses. The injection of interferon was performed in 5 cases, and the local injection of cidofovir was performed in 1 case. Malignant transformation of the papilloma was confirmed in 3 cases. The periods between the onset of papilloma and the malignant transformation were 40 years, 14 years, and 3 years. The present study indicates that patients with laryngeal papilloma developing at multiple sites have a significantly higher rate of relapse, even in the adult-onset group. There was no tendency in the period observed between the onset of papilloma and malignant transformation. From the standpoint of recurrence and malignant transformation, patients with papillomatosis should be carefully followed up for a long period of time.