Irregular scarred kidney with pelvic dilatation is seen with -

Ans. is 'a' i.e., Chronic pyelonephritis Pathological changes of chronic pyelonephritis area) Irregular scarring of kidneyb) The hallmarks of chronic pyelonephritis are coarse corticomedullary scars overlying blunted calyces; dilated pelvis and flattening of papillae.c) The microscopic changes involve predominantly tubules and interstitium; and include :-o Atrophy of tubules in some areas and hypertrophy or dilatation in other areas.o Thyroidization of tubules :- Dilated tubules with flattened epithelium filled with colloid casts resemble colloid containing thyroid follicles.o Chronic interstitial inflammation with interstitial fibrosisd) Arcuate and interlobular vessels demonstrate obliterative intimal sclerosis in the scarred areas; and in the presence of hypertension, hyaline arteriosclerosis is seen in the entire kidney.