Upper tract urothelial carcinoma with pure non-urothelial histology is an exception but variants are present in ~ 25% of cases. Primary upper urinary tract signet -ring cell carcinoma is extremely rare.
Upper tract urothelial carcinoma with pure non-urothelial histology is an exception but variants are present in ~ 25% of cases. Primary upper urinary tract signet -ring cell carcinoma is extremely rare.