Plasmocytoid urothelial carcinoma - clinical, histological, immunohistochemical and molecular aspects

Abstract Plasmacytoid (PUC) variant is a rare and aggressive form of urothelial cancer representing 1 to 3% of the bladder cancer. The main differential diagnosis is the bladder involvement by lymphoma-plasmocytoma or metastasis from lobular breast cancer or diffuse gastric cancer. Immunexpression of cytokeratin 7 and GATA3 is the rule, but CD138 may be positive in high percentage of cases. CDH1 somatic mutation or, more rarely, methylation of the gene promoter is the main genetic characteristic of PUC, but germinative mutation is always negative. The recognition of this special histology is very important for the correct management of the patients because of the high rate of positive surgical margins and atypical disease progression. PUC is responsive to cisplatin-based chemotherapy but recurrence is the rule. Peritoneal dissemination is frequent and cancer specific mortality is as high as 56% in a range of 19 to 23 months.