Histologic review of cidofovir-treated recurrent respiratory papillomatosis

Recurrent respiratory papillomatosis is currently the most common lesion of the larynx in children. The course of the disease is variable and often requires repetitive surgical interventions to maintain the airway. The predominant concern for disease progression is the possibility of spread to the tracheobronchial tree, as this increases the rates of morbidity and mortality. Cidofovir is an antiviral drug with activity against members of the DNA virus family. Development of local malignant change secondary to use of cidofovir has been a concern. The histopathologic findings from biopsy specimens from children treated with cidofovir have not been previously reported.

We performed a retrospective review of pediatric operative histologic biopsies and charts of patients treated with intralesional cidofovir and untreated study controls from January 1, 1995, through November 1, 2001.

Ninety-six specimens were evaluated by 2 blinded pathologists. No cases of dysplasia were identified. The most commonly identified finding was an increased nucleus-to-cytoplasm ratio in 8 of 95 cases (8.4%). No cases of abnormal mitoses, prominent nucleoli, or cellular or nuclear enlargement were found.

This is the first report of pathologically evaluated recurrent respiratory papillomatosis specimens taken before and after treatment with intralesional cidofovir. No dysplasia was identified, and there were no significant dysplastic changes in the specimens analyzed.