UKMLA PLAB AMC USMLE Prometric MCQ

Correct Answer: C

Explanation:
Any clinical presentation usually occurs after age 20. The most common presentation is renal colic (50% to 60%) followed by urinary tract infection (20% to 33%) and gross hematuria (10% to 18%). In many cases, the diagnosis is made when a patient is evaluated by intravenous urography. Characteristic puddling of contrast medium in the ectatic papillary collecting ducts makes the diagnosis of medullary sponge kidney. for some unrelated problem, such as a renal mass, benign prostatic hyperplasia, or hypertension. Rarely is such hypertension attributable to the medullary sponge kidney unless there is pyelonephritis. In general, intravenous urography is more sensitive than CT in detecting mild cases of medullary sponge kidney. In 75% of patients, the disease is bilateral, but, in some, only one pyramid may be affected. The urographic features of the disorder are as follows: (1) enlarged kidneys, sometimes with calcification, particularly in the papillae; (2) elongated papillary tubules or cavities that fill with contrast medium; and (3) papillary contrast blush and persistent medullary opacification. In some cases, the papillae resemble bunches of grapes or bouquets of flowers, whereas in others, discrete linear stripes appear that can be counted readily.