Urine cytological findings of plasmacytoid urothelial carcinoma of urinary bladder: Report of two cases

摘要

Plasmacytoid urothelial carcinoma (PUC) is a rare but distinctive variant of urothelial carcinoma (UC). Since the initial reports, over 20 cases have been described to date. PUC is unusual in that the cancer cells apparently resemble plasma cells. In the first report of PUC, fine needle aspiration cytology of the metastatic lesion was confused with multiple myeloma. Despite its seemingly plasma cell-like appearance, the epithelial nature of PUC can be demonstrated by immunohistochemistry. As the number of reported PUC cases is small, the clinico-pathological characteristics of PUC are still poorly understood. Nevertheless, PUC is generally regarded as a high-grade cancer with frequent stromal/vascular invasion, and is often at an advanced stage when diagnosed. Thus, it is clinically important to diagnose PUC accurately at an early stage when radical treatment is feasible.