Micropapillary variant of urothelial carcinoma: a report of 4 cases and literature review.

Micropapillary variant of urothelial carcinoma (MPUC) is an uncommon variant of urothelial carcinoma with high metastatic potential. The cases reported in the literature were associated with high grade and advanced stages of the disease at presentation and had a poor prognosis. Four patients were diagnosed with MPUC at our center. One patient had an MPUC located in the urinary bladder, and the other three had MPUC originating from the kidney and/or the ureter respectively. All these lesions were confirmed pathologically and treated by radical surgery. Three of the four patients were found to be in the advanced stages of the disease. Although adjuvant chemotherapy was administered, the first and second patients died after 15 and 10 months, respectively. The third and fourth patients are being followed up at our hospital 5 and 27 months after surgery, respectively. Clinically, MPUC is far more aggressive than conventional urothelial carcinoma. Patients with MPUC should be diagnosed promptly and treated aggressively.