The differential diagnosis for large kidneys (often demonstrated on renal ultrasound) is interesting, as there are a few conditions which are especially associated with this finding. Of course, with any type of chronic damage, the kidneys tend to scar down and atrophy.
1. HIV Nephropathy. 2. multiple myeloma. 3. the early stages of diabetic nephropathy. 4. any type of infiltrative process--classically amyloidosis or sarcoidosis of the kidney. 5. autosomal dominant polycystic kidney disease. 6. pyelonephritis. 7. any type of very acute nephritis (e.g., RPGN).