Urothelial Carcinoma - Plasmacytoid Variant

Comments:
This high-grade variant of urothelial carcinoma consists of single tumor cells with plasmacytoid features infiltrating loose myxoid stroma. It may be mistaken for lymphoma, plasmacytoma, metastatic carcinoma, melanoma, or even chronic cystitis. Immunostains such as cytokeratin, lymphoid markers, and S-100 may be useful, especially in small biopsies.