No abstract

Plasmacytoid variant of urothelial carcinoma is a rare subtype of urothelial carcinoma that has poor prognosis. We describe two cases of patients with the plasmacytoid variant of urothelial carcinoma (PVUC) who had initial response to neoadjuvant chemotherapy followed by radical cystoprostatectomy and lymph node dissection but presented with early relapse and disease progression manifesting with intestinal obstruction and peritoneal carcinomatosis. Tumor genomic sequencing revealed mutations and alterations in ARID1A, CDH1, PIK3CA, RB1 loss, and TERT promoter, as well as tumor mutational burden of 10 Muts/Mb treated with pembrolizumab with a minimal response. A further review of the literature regarding this rare variant is discussed here.