Malignant transformation of a highly aggressive human papillomavirus type 11-associated recurrent respiratory papillomatosis

Objective: The objective is to present an uncommon case of squamous cell carcinoma (SCC) arising from extensive recurrent respiratory papillomatosis (RRP) involving the upper and lower airway and temporal bone. Study Design: This is a case report and a review of the literature. Methods: We describe a case of a 24-year-old woman with a history of human papillomavirus (HPV) type 11 since childhood originating in the larynx and trachea, then progressing to involve the distal pulmonary alveoli and right middle ear through the eustachian tube. Papillomatous growth was treated with multiple surgeries including laser cytoreduction of laryngotracheal papillomatosis and radical mastoidectomy, followed by a trial of chemotherapy. Despite this aggressive treatment regimen, papillomatous growth progressed with recurrence in the right eustachian tube, middle ear, and mastoid eventually extending to involve the calvaria and scalp. Results: The patient underwent a composite resection of involved tissues, including the scalp, auricle, and lateral temporal bone, with reconstruction using a latissimus dorsi free flap. Final pathologic analysis revealed an extensive infiltrative well-differentiated SCC arising from the papilloma. A review of the literature on aggressive respiratory papillomatosis suggests that malignant transformation of juvenile-onset RRP occurs exclusively in cases positive for HPV-11. Conclusions: We report an unusual case of SCC originating from extensive RRP involving the airway, temporal bone, and scalp and describe the medical and surgical management. Although the incidence of juvenile-onset RRP transformation to SCC is very low, the presence of HPV-11 as a risk factor for malignant transformation of RRP is becoming evident.