Urothelial Carcinoma-in-situ

Comments:
The image shows urothelial carcinoma-in-situ (CIS) involving Brunn nests (bottom). The neoplastic cells show nuclear enlargement and hyperchromasia, pleomorphism, apoptosis, and increased mitotic activity. The presence of neoplastic cell clusters within lamina propria may be overdiagnosed as invasion. Brunn nests with urothelial CIS can be recognized by their round contours and the lack of stromal changes around them.