FDG PET/CT Findings of Recurrent Respiratory Papillomatosis With Malignant Degeneration in the Lung.

: Recurrent respiratory papillomatosis is a rare benign disease caused by HPV-6 or HPV-11. The tumors may rarely undergo malignant degeneration. We performed FDG PET/CT in a patient experiencing recurrent respiratory papillomatosis who had pulmonary involvement. Although squamous cell carcinoma was detected in one of the pulmonary masses, squamous metaplasia with dysplasia were detected in the other one. Intensity modulated radiation therapy was performed to treat the malignancy. Second FDG PET/CT was performed 15 months after radiotherapy.