The nested variant of transitional cell carcinoma - A rare neoplasm with poor prognosis

The "nested" variant of transitional cell carcinoma is a rare variant compo sed of apparently clusters of urothelial cells, of benign appearance, which often simulate von Brunn's nests and invade into the lamina propria or dee per. Only 36 cases have been reported to date and herein we report an addit ional 10 cases. Of these 10 cases treated with locoregional therapy, seven died of disease or treatment complications 4-40 months after diagnosis whil e one patient died of unrelated disease after 90 months. Follow-up is less than or equal to 1 year for the remaining two patients. Our data and a revi ew of the literature supports the assertion that the nested variant of tran sitional cell carcinoma is an aggressive neoplasm.