What is expected in the kidney pathology of a patient suffering from severe chronic hypertension?

In the context of severe chronic hypertension, hyperplastic arteriolitis is expected in the kidney pathology. This condition is characterized by the proliferation of smooth muscle cells in the walls of arterioles, resulting in a characteristic "onion-skin" appearance. This remodeling of the arteriolar walls occurs as a response to the high pressure and leads to narrowing of the lumens. As a result, this can cause ischemia and damage to renal glomeruli and interstitium, contributing to further deterioration of kidney function over time.

In addition to causing damage through ischemia, hyperplastic arteriolitis reflects the underlying vascular pathology associated with chronic hypertension, where the high blood pressure induces changes that ultimately affect renal perfusion and function. This process can lead to secondary changes like nephrosclerosis, which is further exacerbated by the ongoing hypertension.

The other conditions listed do not align as closely with the expected kidney pathology seen in severe chronic hypertension. Conditions such as ischemic necrosis of the renal medulla, focal segmental glomerulosclerosis, and chronic pyelonephritis may occur due to different injury mechanisms or conditions, but hyperplastic arteriolitis is specifically associated with the vascular changes induced by sustained high blood pressure.