Respiratory papillomatosis is the most common non-cancerous tumor of the upper airway in children. It is caused by the human papilloma virus.  RRP is a small “wart-like” growth. It can be found in the nose, pharynx (throat), larynx (voice box), trachea (windpipe), esophagus (swallowing tube) and the lungs.

RRP in the voice box is the most common.