cystic kidney dz

Question 1

____________________are epithelium-lined cavities filled with fluid or semisolid material. They develop primarily from renal tubular elements

Answer 1

renal cysts

Question 2

How common is it to have renal cysts?

Answer 2

50% of all people > 50 years old have renal cysts. Rarely symptomatic

Question 3

If you see a kidney mass on imaging, what are you concerned about?

Answer 3

differentiating b/t cyst, malignancy, abscess, or polycystic kidney dz

Question 4

What 3 criteria must a renal mass meet to be considered benign?

Answer 4

US:

1) “echo free”
2) sharp borders with smooth walls
3) enhanced back wall (only seen if mass is fluid filled)

Question 5

Your patient has multiple cysts in bilateral kidneys. Her kidneys are large and palpable. She has htn and abdominal pain. What do you suspect?

Answer 5

Polycystic kidney disease

Question 6

How do you get polycystic kidney disease?

Answer 6

Autosomal dominant (pretty common, 1:800)

Question 7

Your patient, with known polycystic kidney disease calls your office frantically after noticing gross blood in her urine. what do you tell her?

Answer 7

This is common, and is likely due to the rupture of a cyst into the renal pelvis which sends the blood to the bladder. Tell her if she experiences continuing pain to come in to r/o a kidney stone (which is more common for patients with her disease) or UTI. (Repeated episodes of hematuria necessitate eval for development of carcinoma…maybe don’t tell her that)

Question 8

You have another polycystic kidney disease patient who is complaining of flank pain and a fever. You have them come to the office and give you urine. Urine sample shows leukocytosis, but no blood. What is your dx? How will you treat?

Answer 8

Suspect infected renal cyst, confirm with CT. Treat with flouroquonolones or sulfa + chloramphenicol (need med that will penetrate cyst wall)

Question 9

You’ve just diagnosed a patient with polycystic kidney disease. You want to counsel them on prevention of kidney stones since they are so common with this disease (20%). What will you recommend?

Answer 9

Hydration!!! and possibly calcium oxalate.

Question 10

How is htn and polycystic kidney disease related?

Answer 10

Cysts can impinge on the vessels in the kidneys causing ischemia, which in turn activates the RAAS. Treat by decompressing cysts and aggressively treating htn.

Question 11

There are 2 random other risk factors for patients with polycystic kidney disease (no real explanation in our text, surprise surprise). What are they?

Answer 11

1) Aneurysm (cerebral in 15% and aortic occasionally)

2) Valve problems (MVP, aortic valve)

Question 12

What treatment do we recommend for polycystic kidney disease patients?

Answer 12

Controversial, of course. Text indicates use of Vasopressin. Avoid caffeine (which prevents cyst formation). Tx htn.