Malignant renal tumors should be classed with syphilis and tuberculosis as among the great mimics encountered in clinical medicine. By direct pressure, by necrosis or hemorrhage, by extension or by metastasis they can reproduce the clinical appearances of an amazing variety of disorders. This fact is often mentioned but rarely emphasized in discussions of renal neoplasms. My attention was first attracted to this fact by 2 cases in which fever was a prominent feature.1 Study of the cases of renal tumor at the University Hospitals and in the department of pathology of the University of Minnesota showed that in many cases the tumor had mimicked some other disease, particularly at the time of onset of symptoms; hence further investigation seemed advisable. With this end in view a group of 92 cases was studied.
It is difficult to discuss neoplasms of the kidney without becoming involved with their nomenclature.