Renal Cysts Flashcards
What are age related reasons for developing renal cysts
Adults: genetic (PKD) or non-genetic
Kids and adults: chronic renal failure leading to acquired renal cysts
What are simple renal cysts
round/oval cysts w/ ONE epithelial layer lining, filled with clear or straw colored fluid
in cortex or medulla
Are simple renal cysts dangerous
Not really, no risk for HTN, cancer, CKD, or ESRD
Incidental findings
Simple renal cysts rarely (but still might) cause
Obstruction of calyxes or renal pelvis
Rupture (Sx: flank pain, hemturia)
Infection (Sx: fever, lumbar/abd pain, hematuria, pyuria)
HTN (d/t compression of a&v in renal parenchyma)
How do you treat hypertension caused by simple renal cysts
ACE/ARB
On US, what do Simple renal cysts look like compared to complex renal cysts
Simple: sharply demarcated, smooth thin walls, no echoes/debris, enhanced back wall (good transmission)
Complex: thick walls, septations, calcifications, solid parts, mixed echogenicity, vascularity
What if you get an US and it is shady?
Get a CT with and without to further eval the cyst
What do we need to know about Bosniak categories
IIF: >3cm, thick walls, calcifications— likely benign, repeat imaging in 3-6 mo
III: masses, enhancement— high change malignancy, monitor or excise
IV: masses and soft tissue enhancement next to cyst wall– very high malignancy
Describe acquired renal cysts
Bilateral, 4+ cysts, due to chronic renal failure
kidneys are small-normal size
rarely symptomatic
When should you screen for acquired renal cysts
yearly after being on dialysis 3-5 yrs.
Use US vs CT with and without
Acquired renal cysts have a small chance of
increase in Renal cell carcinoma risk
How do you treat a simple/complex renal cyst
based on Bosniak!
Pain? APAP (or NSAID if they have normal renal fxn)
Persistent pain/ cyst >5cm? percutaneous aspiration w/ injection of sclerosing agent (tetracycline)// OR laparoscopic unroofing
What is Autosomal Dominant PKD
hereditary PKD due to PKD1/2 mutation, often clinically silent
How are PKD 1/2 different
PKD1: aggressive form
PKD2 slow growth
(most are due to family history, only 5% spontaneous)
ADPKD leads to
irreversible decrease in renal function (in 40’s)
-GFR decreases 4.4-5.9 every year
1/2 pts have ESRD by 60 y/o
What is the pathology of ADPKD
gene mutation= obstructed tubules= cysts= parenchyma compression= decrease in renal function
What is the etiology of ADPKD
Bilateral cysts that cause gradual loss of renal parenchyma, significant renal enlargement (up to 4000g), and a decrease in GFR
When does ADPKD present and how (Sx)
30-40 y/o
abd pain, flank pain, back pain, chest pain
frequent UTI’s
+/- hematuria, pyuria
What is your RED FLAG symptom of ADPKD
Hypertension and palpable kidneys!!!
How do you treat the recurrent UTI’s associated with ADPKD
Quinolones (Ciprofloxacin)
What does ADPKD screening include
US (CT/MRI only if US is inconclusive)
CBC, CMP, UA, genetic screen for diagnosis
What manifestations are associated with ADPKD
Hepatic cysts (estrogen sensitive) Pancreatic/splenic cysts aneurysm MVP colonic diverticuli
How do you treat ADPKD
Nothing definitive, only symptomatic Tx
HTN: ACE/ARB, decrease Na and caffeine
Pain manage, avoid nephrotoxic agents, avoid contact sports
ESRD: dialysis or transplant
What is Medullary Sponge kidney
usually a sporadic congenital disorder (rarely FHx) that is asymptomatic
Leads to collecting tubule dilation and medullary cysts
What are complications of medullary sponge kidney
Nephrolithiasis
UTI
Hematuria
Decreased urine concentration
How do you diagnose medullary sponge kidney
CT (shows cystic dilation of distal collecting tubule)
usually in 40-50 y/o
How do you treat medullary sponge kidney
good hydration
If hypercalcemic, thiazide diuretic
*Renal function is usually maintained
What is medullary cystic disease
Autosomal Recessive disease due to multiple gene mutations
causes ESRD before 20 y/o
varies based on age of onset (infantile, juvenile, or adolescent)
What are findings consistent with medullary cystic disease
Decreased urine concentrating ability (bland urine, polyuria, polydipsia)
tubulointerstitial nephritis with cysts developing after 9 years old
How do you diagnose medullary cystic disease
Clinical characteristics (polyuria/dipsia)
retinitis pigmentosa (blindness)
confirm with genetic testing
US shows mild decrease in kidney size, increased echogenicity, and no corticomedullary differentiation
How do you treat medullary cystic disease
Supportive care :(
