Inverted Papilloma
Background
Inverted papillomas are nasal tumors that originate in the mucosal membrane of the nasal cavity and paranasal sinuses. Papillomas are benign epithelial tumors that grow outward in fingerlike projections. In the case of inverted papillomas, these projections invaginate inward and into the underlying bone. These tumors are locally aggressive, often recur and can become malignant. Squamous cell carcinoma is the most common malignancy associated with inverted papillomas.
Causes
The causes of inverted papillomas have not been definitively established. Chronic sinusitis, airborne pollutants and viral infection have all been proposed as contributing factors.
Viruses have been suspected due to the high incidence of recurrence, as well as studies which show the presence of subtypes of human papilloma virus (HPV) in some inverted papilloma samples.
Risk Factors
- male sex: inverted papillomas occur 2-3 times more often in males than in females
- history of sinusitis
Symptoms
- nasal obstruction, usually one-sided
- rhinorrhea (runny nose)
- epistaxis (nosebleed)
- sinusitis
- facial pain
- loss of sense of smell
- frontal headache
Diagnosis
Most inverted papillomas can be found during a physical examination of the nasal cavity. They have a reddish-grey appearance and may bleed when touched. The septum may be bowed by the mass, and facial swelling and proptosis (bulging of the eyes) may accompany lesions that have expanded considerably. Imaging studies reveal the extent to which the tumors have spread and the degree of bone destruction. An MRI is preferred because it allows inverted papillomas to be better distinguished from other types of lesions. Biopsy is necessary to make a definitive diagnosis.
Treatment
Surgery is the primary treatment for inverted papillomas. Because of high recurrence rates (40-80%), early aggressive surgery is usually recommended. The traditional procedure is a lateral rhinotomy with medial maxillectomy. This approach involves making an incision along the side of the nose up to the eyebrow, which enables sufficient exposure for removal of affected areas of the ethmoid sinus and maxilla (upper jawbone). Other open approaches include lateral osteotomy of the nasal bone and midfacial degloving.
Inverted papillomas of the sinuses, nasal cavity, and of the skull base can be directly approached through expanded endonasal approach (EEA). This state-of-the-art, minimally invasive surgical procedure uses the nose as a natural corridor to reach these lesions. There are no incisions in the skin of the face or head.
Endoscopic approaches have become more widely used in recent years, with good success rates in preventing recurrence and better cosmetic outcomes.
Prevention
There are currently no guidelines for preventing inverted papillomas.