Today I looked at a case of an exophytic, papillomatous nasal tumour with hyperplastic squamous epithelium which was cytologically really very bland. It was a exophytic Schneiderian papilloma which is common in the nose where there is not much opportunity for it follow a inverted growth pattern.
- Exophytic- Common. With scheiderian papillomas it is worth looking for cilia on the surface as the epithelium may be transitional between squamous and columnar. Thought to be assoc with HPV 6 & 11.
- Inverted – Benign but locally invasive with high recurrence
- Cylindrical – The surface epithelium shows oncocytic change with microcysts filled with neutrophils
There is a small risk of malignant transformation in inverted and cylindrical schneiderian papillomas.
- Squamous papillomas – may be keratinising
- Squamous carcinoma – more pleomorphic, infiltrative
Gattuso. Differential Diagnosis in Surgical Pathology
Robbins & Cotrans. Pathologic Basis of Disease.