Renal Cysts

Question 1

Three types of renal cysts?

Answer 1

simple (Bosniak category 1), complex (Bosniak category 2) , cystic mass (Bosniak category 3 and 4)

Question 2

imaging findings of simple cyst?

Answer 2

round, thin, smooth and regular border

no septa, calcifications, solid components, posterior enhancement on U/S, and no contrast enhancement on CT scan or MRI

Question 3

Tx of simple cysts

Answer 3

reassurance <1% malignancy risk

Question 4

Findings on U/S of complex cysts

Answer 4

few septa, calcification, no contrast enhancement on CT scan or MRI

Bosnaik II <3 cm

Bosnaik IIF >3 cm

Question 5

Tx of Complex Renal cysts

Answer 5

Bosnaik II: reassurance (<3% malignancy risk)

Bosnaik IIF: follow up imaging in 6 -12 months with a 5-10% malignancy risk.

Question 6

Tx with Bosnaik II renal cyst

Answer 6

reassurance (<3% malignancy potential)

Question 7

Tx of Bosnaik IIF renal cyst

Answer 7

repeat imaging in 6-12 months (5-10% malignancy risk)

Question 8

Cystic mass findings

Answer 8

thick, irregular wall
multiple thick septa, often with calification
enhancement on CT scan/MRI (Category IV cysts have enhancing soft tissue components)

Question 9

Tx of Cystic masses

Answer 9

surgical excision of mass or nephrectomy (>90% chance of malignancy)

Question 10

Why do we see posterior wall enhancement in simple cysts?

Answer 10

technical artifact seen on U/S studies that indicates ultrasound wave transmission beyond the cyst and doesn’t equate with contrast enhancement on CGT scan or MRI.

Question 11

Do we ever get a percutaneous needle aspiration of a renal cyst?

Answer 11

only indicated for lesions that demonstrate abscess or purulent fluid >10 cm and painful. Can check for malignancy if papillary renal cell carcinoma.

Question 12

When do we see renal cysts?

Answer 12

simple renal cysts are seen in adults >50 yrs.

Question 13

ultrasound characteristics of ppl with autosomal dominant polycystic kidney disease

Answer 13

Age 15-39 >3 unilateral or bilateral kidney cysts
Age 40-59 >2 cysts in each kidney
Age>60 >4 cysts in each kidney

Question 14

Unknown family history

Answer 14

multiple (usually >10 in each kidney regardless of age)

Question 15

other medical conditions associated with autosomal dominant polycystic kidney disease

Answer 15

hepatic cysts 20-80%, cerbral aneurysms 5-20% and cardiac valvular dx or mitral or aortic regurgitation and diverticulosis

Question 16

how to confirm autosomal dominant polycystic kidney disease

Answer 16

genetic testing

Question 17

how to monitor autosomal polycystic kidney disease

Answer 17

U/S and supportive care.

Question 18

difference between medullary sponge kidney and ADPKD

Answer 18

Medullary spong kidney has dilated collecting ducts in the medullary pyramids that is sometimes confused for radiographic appearance of ADPKD.

Question 19

major extrarenal complications of ADPKD

Answer 19

intracranial aneurysms
hepatic and pancreatic cysts
cardiac valve disease and aortic root dilation
diverticulosis

Question 20

pt has hypertension, hematuria, proteinuria renal insufficiency and bilateral flank masses who presents with severe headache, altered mental status and nuchal rigidity. what does she have?

Answer 20

has possible subarachnoid hemorrhage as a result of ruptured intracranial aneurysm from her autosomal dominant polycystic kidney disease

Question 21

who has highest risk for development of intracranial aneurysms with autosomal polycystic kidney disease?

Answer 21

>60 yrs old (20%)
young adults (5%)

higher risk in pts with family history of ruptured aneurysms

Question 22

screening for intracranial aneurysms is controversial in autosomal polycystic kidney disease because:

Answer 22

routine screens can see small aneurysms <7 mm that are low risk for rupture but surgical intervention of aneurysms can cause higher neurological complications

guidelines recommend screening pts with previous aneurysm rupture and family history of intracranial bleed or aneurysm and high risk occupations (pilots)

Question 23

best screening test for intracranial aneurysms in pts with autosomal polycystic kidney disease

Answer 23

time of flight magnetic resonance angiography and can be done at any GFR.

CT angiography is alternate screening method.