Malignant transformation of HPV-11-associated recurrent respiratory papillomatosis

Objective: To present an uncommon case of squamous cell carcinoma (SCC) arising from severe recurrent respiratory papillomatosis (RRP) involving the upper and lower airway and temporal bone. Study Design: Case report and a review of the literature. Methods: We describe a case of a 24 year old woman with a history of human papilloma virus (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 extending to involve the calvarium 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 squamous cell carcinoma arising from the papilloma. A review of the literature on aggressive respiratory papillomatosis suggests that malignant transformation of juvenileonset 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.