MICROSCOPIC DESCRIPTION: 1. Sections show fragments of tissue with many bulbous nests of bland squamous epithelium within an oedematous stroma. The surface of most fragments is bland squamous epithelium. There is a predominantly neutrophil infiltrate within the epithelium with some microabscesses. Keratinisation is not prominent. There is some cytoplasmic clearing. Nuclear features are for the most part bland, with some areas showing reactive atypia. There is no evidence of malignancy.
DIAGNOSIS: Schiederian papilloma, inverted type.