Micropapillary variant of transitional cell carcinoma of the ureter

Micropapillary variant of transitional cell carcinoma (TCC) is a rare entit y, having a distinct micropapillary component mimicking papillary serous ca rcinoma of the ovary and has been reported exclusively in the urinary bladd er. We experienced a case of micropapillary variant of TCC in the ureter. T he tumor showed a predominant proportion of micropapillary component and ac companied a TCC in situ lesion and a high-grade TCC. A metastatic lesion in the regional lymph node also showed an entirely micropapillary pattern. In itially, our case was confused with adenocarcinoma, especially metastatic, because the micropapillary architecture resembled an abortive glandular str ucture and tumor cell nests were predominantly located in empty spaces mimi cking vascular invasion. The patient died with peritoneal metastases 20 mon ths after the initial diagnosis. We report the first case of a micropapilla ry variant of TCC occurring in the ureter.