Plasmacytoid carcinoma (PC) is a rare, aggressive subtype of UC defined by the presence of single, discohesive malignant cells, with eccentric nuclei and abundant eosinophilic cytoplasm with occasional vacuoles, likewise plasma cells, hence the name; loss-of-function non-sense mutations of cadherin 1 (CDH1) gene encoding for the cell adhesion protein E-cadherin can be identified in the vast majority of cases, resulting in lack of staining for e-cadherin immunohistochemical antibody [10,97,123]. This evidence concerns the gene CDH1 and pachyonychia congenita.