Talk:High-grade papillary urothelial carcinoma

Flat atypical in background

The sections show urothelial mucosa with thick papillary structures. Focally, nuclei are large (~3-4x resting lymphocyte), hyperchromatic and have nucleoli. Mitotic activity is present and focally brisk (4 mitoses in 1 HPF, 1 HPF~0.2376 mm*mm). Flat atypical urothelium with proliferation is present in the background; this may be from the edge (or shoulder) of the lesion or it could be in situ disease.