Micropapillary Urothelial Carcinoma: A Review and Update

Micropapillary urothelial carcinoma is a well-recognized subtype of urothelial carcinoma that is associated with an aggressive clinical course. Its recognition is critical for optimal management; however, strict diagnostic criteria are not always applied, resulting in interobserver variability in recognition and reporting. The genomic profiles of micropapillary urothelial carcinoma overlap with those of classic urothelial carcinoma, but show higher rates of alterations in the cell cycle regulators TP53 and RB1 and the receptor tyrosine kinase ERBB2 . Recently approved therapeutic agents targeting cell surface markers such as HER2 and NECTIN4 provide promising novel and potentially more effective therapies for micropapillary urothelial carcinoma.