Genomic Characterization of Plasmacytoid/Signet-ring Carcinoma (PC/SRC) of the Bladder

In this study, six plasmacytoid bladder cancers were analyzed by whole exome sequencing. The results show loss of the CDH1 gene in every sample and correlate with E-cadherin loss of expression by immunohistochemistry. A separate validation cohort of plasmacytoid samples showed loss of E-cadherin expression by CDH1 mutation or promoter hypermethylation.