Some of the low power figures show an architectural pattern of an inverted Schneiderian papilloma. Other low power figures, however, show focal surface erosion/ulceration and irregular epithelial nests of varying sizes surrounded by desmoplasia consistent with stromal invasion. Medium- and high power figures clearly show a high grade invasive carcinoma. A superficial layer of benign ciliated columnar epithelia focally overlies multiple layers of dysplastic cells underneath, an observation in support of a pre-existing inverted Schneiderian papilloma. The neoplastic growth is endophytic and not exophytic/papillary. Nomenclature of this type of malignancy is not standardized, and the best term in my opinion is Schneiderian carcinoma because it delivers the association with inverted Schneiderian papillomas. However, the current (2003) WHO classification of head and neck tumors would put this case under the category of non-keratinizing squamous cell carcinoma. It is, in my opinion, a high grade carcinoma.
Some of the low power figures show an architectural pattern of an inverted Schneiderian papilloma. Other low power figures, however, show focal surface erosion/ulceration and irregular epithelial nests of varying sizes surrounded by desmoplasia consistent with stromal invasion. Medium- and high power figures clearly show a high grade invasive carcinoma. A superficial layer of benign ciliated columnar epithelia focally overlies multiple layers of dysplastic cells underneath, an observation in support of a pre-existing inverted Schneiderian papilloma. The neoplastic growth is endophytic and not exophytic/papillary. Nomenclature of this type of malignancy is not standardized, and the best term in my opinion is Schneiderian carcinoma because it delivers the association with inverted Schneiderian papillomas. However, the current (2003) WHO classification of head and neck tumors would put this case under the category of non-keratinizing squamous cell carcinoma. It is, in my opinion, a high grade carcinoma.