Inverted Papillary Uroth. CA, High-Grade : Microscopic

Microscopic Features: Inverted urothelial carcinoma, high-grade may be invasive or non-invasive. Non-invasive tumors have smooth contours at epithelial-stromal interface. This image shows lamina propria invasion. Features suggestive of invasion include: irregularity of the stromal-epithelial interface, small irregular nests in the lamina propria (seen here), retraction artifact, or desmoplasia. Invasive tumors are more likely to show hypercellularity, loss of polarity, severe nuclear atypia, increased mitotic activity (including atypical mitoses), apoptosis, luminal necrosis, irregularly thickened and complex trabeculae, neovascularization, and cellular discohesiveness.