The general facts and clinical details concerning tumors of the pelvis of the kidney are well known. Though such tumors are rare, there have been several reviews of series of cases, and each year there have been isolated case reports reemphasizing this knowledge.
There were apparently 218 cases reported in 1927, and from then until 1932 there were 30 additional cases (Mackenzie and Ratner1).
Tumors of the renal pelvis constitute from 1 to 10 per cent of all renal tumors. Five per cent is the average figure usually stated. There are two varieties: the squamous cell tumors, which are the rarer and of which the literature contains only about 60 cases (Higgins2), and the papillary tumors, which comprise three fourths of the total number.
The squamous cell growths are the more malignant. They are usually grade 3 or 4 (Broders' classification), are frequently accompanied by stones and chronic
SALTZSTEIN HC, BEAVER DC. PAPILLARY CARCINOMA OF THE PELVIS OF THE KIDNEY. Arch Surg. 1940;40(5):949–958. doi:10.1001/archsurg.1940.04080040131012