The rarity of primary carcinomas of the ureter, together with the fact that they are often not even suspected, warrants the presentation of six proved cases and a probable seventh case. Caulk,1in his compiled series, together with Hunt2and others, found less than 7 per cent of renal tumors primary in the pelvis, while Thomas and Regnier3in 253 collected cases of carcinoma of the renal pelvis and ureter found 15 per cent primary in the ureter. These figures suggest that about 1 per cent of carcinoma of the upper part of the urinary tract originate in the ureter. HISTORY Wising and Blix4in 1878 reported the first authentic case with a microscopic diagnosis, an instance of medullary carcinoma with metastasis to retroperitoneal nodes, rectum and perineum. Up to 1900, eight cases had been reported, in all of which the diagnosis had been made at