Inverted papilloma is a benign but locally aggressive tumor that arises in the nasal cavity and paranasal sinuses. The tumor is part of a family of tumors called schneiderian papillomas. The inverted type is the most common and found in all parts of the paranasal sinuses. It is traditionally identified in patients with a history of sinonasal infections. Despite being a benign tumor approximately 5-12% of tumors can convert into squamous cell carcinoma (an aggressive malignant tumor) and thus inverted papilloma should be treated aggressively. The underlying etiology of inverted papillomas is still unknown. Although investigation has looked into an association with human papilloma virus (HPV) no definitive evidence has identified this as a risk factor. Inverted papilloma diagnosis is typically made by an office biopsy based on concerning features on CT, MRI or endoscopic appearance in the office.
Patients typically present with complaints similar to chronic rhinosinusitis including nasal congestion, purulent drainage, headaches and postnasal drip. It is not uncommon to be initially treated for a sinus infection multiple times before an evaluation by a specialist. An otolaryngologist will often have a clinical suspicion based on an in office nasal endoscopy but diagnosis cannot be confirmed without a biopsy which can generally be done in the office. In addition a CT scan is done to confirm the presence of a mass and evaluate the size and paranasal sinus involvement. Other areas of concern are segments of missing or eroded bone on the CT scan, or dehiscent bone along the eye or skull base adjacent to the brain. In some situations MRIs are also performed to evaluate extent of tumor extending beyond the paranasal sinuses into the eye or brain or if further characterization is necessary to evaluation the size of the tumor and give clues as to whether any malignant transformation has occurred.
The mainstay of treatment for inverted papilloma is surgery. It is important to go to an experienced surgeon as if not removed completely, inverted papilloma has a high rate of recurrence. Surgical resection is typically performed endoscopically with any areas of tumor attachment to surrounding paranasal sinus bone requiring drilling down of the bone to prevent recurrence. If any concerning features for squamous cell carcinoma are seen on review of the operative pathology, patients may need a wider resection or additional treatments such as chemotherapy or radiation therapy.
Case Example 1:
A 55-year-old male presented to an outside otolaryngologist for headaches. He was initially taken in for balloon sinuplasty and removal of a polyp on the right side. Pathology of the polyp came back as inverted papilloma and the patient was sent to a university hospital for management. On examination the patient has an inverted papilloma in the right nasal cavity with a CT scan demonstrating an attachment of the bone along the skull base (Image 1). MRI confirmed the mass did not go into the frontal sinus itself (Image 2) and his headaches where likely related to trapped fluid in the frontal sinus from obstruction due to the inverted papilloma. See video for surgical resection. He is approximately 2 years out from surgery without evidence of recurrence. Given the location of the inverted papilloma a simple endoscopic evaluation in the office is all that is necessary to confirm no tumor recurrence. Due to the high risk of recurrence of inverted papilloma, long-term follow up is necessary. Typically follow CT scan or MRI is not necessary as long as the area can be seen clearly by endoscopy. Occasionally these tumors originated in challenging to visualize locations in the paranasal sinuses and your surgeon may get routine images for surveillance.
Case Example 2:
48 year old male who states he has “nasal polyps” and had surgery at a different hospital 1 year ago and told he needs no follow up. He presents to our institution with a large nasal mass On biopsy this was consistent with an inverted papilloma. This was originating from the maxillary sinus. Tumor in the maxillary sinus sometimes require a procedure to make an incision under the lip in the mouth to access the very front portion of the sinus that may not be accessible through the nose. We discussed this possibility to him and realized during the surgical procedure that this would be the case (see video). Following surgery, he stayed in the hospital 1 night and went home the next day. Despite having the incision in the mouth (Caldwell-Luc incision) he had no facial bruising or swelling. He is now 1.5 years out from surgery and doing well.
Recommended Further Reading
Bacteriology of inverted papilloma. Kim LY, Cohen NA, Palmer JN, Kennedy DW, Zhang Z, Adappa ND. Rhinology. 2014 Dec;52(4):366-70. doi: 10.4193/Rhin14.007. Read Article
Inverted papilloma of the sphenoid sinus: Risk factors for disease recurrence. Suh JD, Ramakrishnan VR, Thompson CF, Woodworth BA, Adappa ND, Nayak J, Lee JM, Lee JT, Chiu AG, Palmer JN. Laryngoscope. 2014 Nov 24. doi: 10.1002/lary.24929. Read Article
Septal dislocation for endoscopic access of the anterolateral maxillary sinus and infratemporal fossa. Ramakrishnan VR, Suh JD, Chiu AG, Palmer JN. Am J Rhinol Allergy. 2011 Mar-Apr;25(2):128-30. Read Article
Clinical outcomes of endoscopic and endoscopic-assisted resection of inverted papillomas: a 15-year experience. Woodworth BA, Bhargave GA, Palmer JN, Chiu AG, Cohen NA, Lanza DC, Bolger WE, Kennedy DW. 2008 Jan-Feb;22(1):97. Read Article
Radiographic and histologic analysis of the bone underlying inverted papillomas. Chiu AG, Jackman AH, Antunes MB, Feldman MD, Palmer JN. Laryngoscope. 2006 Sep;116(9):1617-20. Read Article