Clinicopathological Review of Micropapillary Urothelial Carcinoma

This review will discuss micropapillary urothelial carcinoma with respect to biology, histopathologic characteristics, genetic and molecular features, diagnosis, clinical management, and future directions of research.

Recent consensus opinion study showed only moderate interobserver reproducibility in the diagnostic criteria. The most reproducible criteria with the highest consensus were multiple nests in the same lacunar spaces. There are recent reports of high rates of intratumoral heterogeneity of ERBB2 amplification within tumor containing both micropapillary and classic urothelial components. Micropapillary urothelial carcinoma is a well-documented highly aggressive variant of urothelial carcinoma with proven worse outcomes. Accurate recognition and reporting of this pattern is critical for optimal management. Newer therapeutic strategies related to the molecular and genetic findings seen in MPUC remain to be explored further.