Fig. 7.

Low-grade non-intestinal-type sinonasal adenocarcinoma. A At low-power, there is a markedly increased number of seromucinous glands within the nasal submucosa. B The tumor glands have minimal cellular atypia, but demonstrate architectural atypia in the form of fusion and cribriforming with no intervening stroma. C A rare variant known as renal cell carcinoma-like adenocarcinoma has water-clear cytoplasm and prominent cell membranes. D S100 protein is usually positive, supporting seromucinous differentiation