Xanthogranulomatous pyelonephritis: A comparison of the disease in the cat and man with special reference to the origin of the fat

The origin of the intracellular fat in human xanthogranulomatous pyelonephritis has been the centre of some discussion in the past. A report of a case in a domestic cat is of interest as normal feline renal epithelium is rich in stainable fat. A comparison of the human and feline varieties of xanthogranulomatous pyelonephritis reveals certain fundamental differences between the two and reinforces the view that the fat concerned in the human disease does not originate in the renal epithelium.