Plasmacytoid variant of urothelial carcinoma: Diagnostic challenges and role of immunohistochemistry.

Plasmacytoid carcinoma of the urinary bladder or plasmacytoid urothelial carcinoma (PUC) is rare and only recently described a histological variant of transitional cell carcinoma. The morphological resemblance of PUC to other malignancies is a source of diagnostic dilemmas and often misdiagnosis. Immunohistochemistry plays a pivotal role in narrowing the differential diagnosis and reaching to a conclusive diagnosis.