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What is renal cystic disease?

- characterized by epithelium lined cavities filled with fluid or semisolid debris within the kidneys


Diff cystic diseases of the kidney?

- simple cyst
- aquired cystic kidney disease
- medullary cystic disorders
- medullary sponge kidney


Simple cysts?

- often asx and usually incidental findings during imaging studies
- increase in frequency with age
- present in up to 50% of pop over 50 yo
- renal US, together with CT diff benign from malignant lesions in most instances


3 main criteria for cyst being benign?

- echogenic free
- finely demarcated (encircled)
- enhanced back wall, good transition through cyst

- calcifications, solid components, echogenicity all concerning - get CT


2 diff categories of polycystic kidney disease?

- ADPKD: adult PKD
- ARPKD: referred to infantile or childhood PKD
abdominal mass in neonate or older infant suggestive
- can occur with congenital fibrosis and causes death from renal failure during the first year of life
- can be picked up on U/S at 20 weeks, progresses to ESRD early on
- renal failure in adolescense suggested ARPKD or medullary cystic disease


What is adult polycystic kidney disease characterized by?

- large cysts
- pts eventually die from renal failure or consequences of HTN (decreased filtration, balance of electrolytes are off)


Etiology of ADPKD?

- msot common hereditary renal disease in US
- affects over 500000 people
- caused by 2 genes:
ADPKD1: 85% of pts
ADPKD2: 10-15%


When do clinical manifestations of ADPKD start?

- rarely occur b/f 20-25 years, therefore affected people of childbearing age pass genetic trait on to offspring while they are still asx
- pts present either from screening b/c of family hx, or for eval of sxs


Most common clinical sx of ADPKD?

- acute abdominal flank pain
- back pain
- will have kidney stones, UTIs, HTN
- hematuria (rupturing into renal pelvis): microhematuria at first, gross hematuria may occu
- non-specific dull lumbar pain
- sharp localized pain: from cyst rupture, infection or passage of renal stone


What are you worried about when you see blood in the urine?

- cancer!!!
- ask about hx of smoking


What are common complications of ADPKD?

pylonephritis: become septic quickly
cyst infections (fluoroquinolones)


What are common assoc with ADPKD?

- mult asx hepatic cysts (30%)
- MVP (25%), aortic valve abnormalities
- cerebral aneurysms (10%)
- diverticulosis


Disease progression of ADPKD?

- renal fxn impairment is variable: 50% progress to ESRF by age 60


Associations of poor prognosis in ADPKD?

- ADPKD1 gene
- male
- black race
- early age of clinical presentation
- episodes of gross hematuria


Dx of polycystic kidney disease?

- RENAL U/S is the best!!!!
- see mult cysts throughout parenchyma
- renal enlargement
- increased corticol thickness
- elongation and splaying of renal calyces
- bilateral renal involvement

- CT: can show more cystic involvement than US, primarily used for diff when few cysts rae seen on US


Dx recommendations?

- based on age and number of cysts present in one or both kidneys for dx in pts with family hx
- extrarenal involvement, particularly hepatic cysts lend support to dx


Dx criteria for ADPKD1?

- at least 2 cysts in 1 kidney or 1 cyst in each kidney in an at risk pt younger than 30
- at least 2 cysts in each kidney in an at risk pt aged 30-59
- at least 4 cysts in each kidney for an at risk pt aged 60 and older


Screening for ADPKD1?

- asx carriers
- expensive
- requires cooperation of other family members
- supplies no anatomic info


Tx of ADPKD1?

- aimed at preventing complications and preserving renal fxn:
tx of HTN (ACEI)
- management of infections: all of these penetrate cyst walls and attain therapeutic levels:
bactrim, chloramphenicol, ciprofloxin

- dialysis: for ESRF
- transplant: for ESRF
- bilateral nephrectomy prior to transplantation in pts with large kidneys or hx of frequent and persistent UTIs


What is ARPKD?

- sxs of autosomal recessive PKD can begin before birth
- often called infantile PKD
- children born with ARPKD usually develop kidney failure within a few years
- severity of disease varies, babies with the worst cases die hours or days after birth
- children with infantile version may have sufficient renal fxn for normal activities for a few years
- people with juvenile version may live into their teens and 20s and usually will have liver problems as well


Clinical presentation of infantile ARPKD?

- hx of oligohydramnios (small amt or lack of amniotic fluid)
- difficult delviery because of enlarged fetal kidneys
- resp distress may be present
- pneumomediastinum and pneumothorax are common
- renal fxn usually compromised - hence the lack of amniotic fluid


Sxs of ARPKD in children?

- high BP
- UTIs
- frequent urination
- disease usually affects liver, spleen, and pancreas, resulting in low blood cell counts, varicose veins, and hemorrhoids
- because kidney fxn is cruicial for early physical development, children with ARPKD are usually smaller than average size


How is ARPDK dx?

- US imaging of fetus or newborn reveals cysts in kidneys but doesn't distinguish b/t cysts of recessive or dominant PKD
- US exam of relatives can be helpful, for ex - parent or grandparent with ADPKD cysts could help confirm dx of ADPKD in a fetus or child, it is extremely rare but not impossible for person with recessive PKD to become a parent
- Because ARPKD tends to scar the liver, US imaging of liver also aids in dx


How is ARPKD tx?

- control of HTN
- abx for UTIs
- eating increased amts of nutritious food improves growth in children with ARPKD
- in some cases GHs are used
- in response to kidney failure, ARPKD pts must receive dialysis or transplantation


Acquired cystic kidney disease?

- development of cysts in pt with chronic renal failure or ESRD undergoing dialysis
- carcinomas may complicate the disorder
- annual screening after 3-4 years on dialysis to r/o malignancy
- CT scan is dx of choice in acquired cystic kidney disease


What are medullary cystic disorders?

- part of a group of congenital tubulointerstitial nephropatheis known as juvenile nephronophthisis - medullary cystic disease complex
- rare autosomal dominant disease


Presentation of medullary cystic disorder?

- anemia
- nocturia (troubles with potty training)
- prolonged childhood enuresis
- low urine osmols
- eye deformities
- short stature
- failure to thrive
- low BP
- eventually, signs of renal failure


Progression of medullary cystic disorder?

- results in ESRF during adolescence of early adulthood


Dx of medullary cystic disorder?

- cysts are really small: 1-2 mm
- radiography and bx are not always successful at detecting these small cysts


Tx of medullary cystic disorder?

- focus on controlling sxs, minimizing complications and slowing progression of the disease
- because of loss of water and salt, the pt will need a liberal intake of both to avoid dehydration
- tx HTN
- tx renal failure sequelae
- dialysis
- transplant (preferred)