Case of progressive dysplasia concomitant with intralesional cidofovir administration for recurrent respiratory papillomatosis.

Recurrent respiratory papillomatosis (RRP) is characterized by benign wartlike growths in the larynx with occasional spread to the lungs. A broad range of therapeutic measures have been used to treat RRP; the primary treatment is laser vaporization of the lesions. Recurrences of the disease are common, and alternate methods of treatment are being used to prevent recurrence, including cidofovir. Cidofovir is a cytosine nucleotide analog with antiviral properties that is approved by the US Food and Drug Administration for treatment of cytomegalovirus retinitis and is currently being used off-label for RRP. Cidofovir has gained initial success in slowing the rate of disease recurrence when used at the time of surgery. However, the use of cidofovir lends concern to several adverse side effects, including the potential for carcinogenesis. We report here a 28-year-old woman who was treated with intralesional cidofovir at the time of surgery over the span of 27 months. The initial pathology results demonstrated benign disease with progression to severe dysplasia during the treatment time. Cidofovir's potential for carcinogenicity remains largely undefined, and thus, we are currently undertaking a project involving the evaluation of sequential paraffin-embedded samples of resections from a large cohort of patients with RRP treated at the University of Iowa Hospitals and Clinics.