Malignant Transformation of Exophytic Sinonasal Papilloma: Case Report

Abstract

Malignant transformation of exophytic sinonasal papilloma (SP) is exceptionally rare. The authors present a case of a 48 years old woman who presented to hospital with unilateral nasal obstruction, a tissue mass in the right nasal entrance. After CT scans of the paranasal sinuses endoscopic surgery was carried out, and the lesion was removed. The histological examination discovered an exophytic SP with a part of squamosus cell carcinoma. The patient underwent radiotherapy. After that the thickened mucosa from the right sinus maxillaries was removed. Histological examination revealed SP fragments in the polypoid mucosa without any sign of malignancy. To date we have found no sign of recurrent papilloma or carcinoma. The pathogenesis of papillomas is not clear. In one third of sinonasal papillomas HPV-6 and 11 are present. In our patient no HPV DNA was identified in the removed tissues. The carcinoma and the dysplastic area was p16 positive, while the exophytic SP epithelium was negative.

Conjunctival Exophytic Schneiderian-type Papillomas: A Rare Occurrence

“…Malignant transformation, termed "carcinoma ex-Schneiderian papilloma," has been reported in inverted and oncocytic papillomas 3 but is exceptionally rare in the exophytic variety. 5,6 Rates of malignant transformation are about 27% or less, usually resulting in squamous cell carcinomas, with better outcomes than tumors deriving de novo from Schneiderian epithelium. 7 To date, only 15 inverted (endophytic) Schneiderian papillomas of the conjunctiva have been described.…”