SFP: cystic disease, renal vessels, outflow obstruction Flashcards
Who do we see benign nephrosclerosis in?
Elderly patients with increased frequency/severity if they have HTN and diabetes.
What are pathophysiologic characteristics of benign nephrosclerosis?
Low GFR, loss of concentrating ability, proteinuria.
What does the kidney look like in benign nephrosclerosis?
Granular due to ischemic changes from a narrowed arteriole secondary to chronic HTN.
What does chronic HTN cause histologically in blood vessels?
Reduplication of internal elastic lamina; can cause luminal obstruction.
When might we see hyaline arteriolosclerosis?
Benign nephrosclerosis secondary to chronic HTN.
What is malignant HTN?
HTN that causes immediate signs of end organ damage.
What is seen in the renal system with malignant HTN/hypertensive emergency?
Renal failure/AKI, stimulation of RAAS and salt retention.
What does the kidney look like in acute hypertensive emergency/malignant HTN?
“Flea-bitten” appearance from rupturing of arterioles or glomerular capillaries.
What is seen histologically in malignant HTN?
Onion-skin lesions and fibrin thrombotic microangiopathy.
What is thrombotic microangiopathy?
Seen in malignant HTN; fibrin thrombi in arterioles and glomeruli that block off blood flow and cause necrosis.
What causes renal artery stenosis?
Atherosclerosis or fibromuscular dysplasia in young women.
Physiologically, what does renal artery stenosis lead to?
Renovascular HTN with elevated renin due to decreased flow.
What morbidities are associated with renal artery stenosis?
Uncontrolled HTN and chronic kidney disease.
What will happen in unilateral renal artery stenosis?
Affected side will be ischemic and side without stenosis will be hypertensive.
What is the pathophysiology of thrombotic microangiopathies?
Clot formation causes a high-pressure system in the vessel that impacts the flow of the blood cells. This causes the cells to shear and form schistocytes in peripheral blood.
What is the most common cause of thrombotic microangiopathies?
Hemolytic uremic syndrome.
When does hemolytic uremic syndrome often occur?
In the setting of GI infection (Shiga toxin from E coli) or Complement-mediated.
What are secondary causes of thrombotic microangiopathies?
Pregnancy, SLE (antiphospholipid antibody), malignant HTN, GI infection.
What defect causes thrombocytopenic purpura?
ADAMTS 13 that breaks down von Willebrand.
What is the triad for presentation of thrombotic thrombocytopenia purpura?
- Hemolytic anemia 2. Thrombocytopenia 3. Renal failure.
What is cystic renal dysplasia?
Congenital abnormality that causes histologic abnormality; can be associated with abnormalities of lower urinary tract.
What is seen on histology in cystic renal dysplasia?
Dilated tubules, primitive stroma, cartilage.
Describe simple cysts in the kidney.
Common and of little consequence that are not carcinogenic; fluid is clear.
What is acquired cystic kidney disease?
Occurs in end-stage renal disease aka those on dialysis or post-transplant. It will happen in the native kidney, not transplanted.
What is the gross pathology of acquired cystic kidney disease?
Multiple cysts in cortex and medulla.
How do we treat acquired cystic kidney disease?
The cysts may have to be removed since they increase risk for neoplasms.
Describe the population of autosomal dominant polycystic kidney disease.
Seen in end stage renal disease in adults.
What genes are associated with autosomal dominant polycystic kidney disease?
PKD1 and PKD2; encode for mechanosensation by cilia and calcium flux.
What do kidneys look like in autosomal dominant polycystic kidney disease?
Huge kidneys with cysts everywhere.
What 3 things are associated with autosomal dominant polycystic kidney disease?
Liver cysts, cerebral berry aneurysms, MVP.
What is a major complication of autosomal dominant polycystic kidney disease?
Subarachnoid hemorrhage.
What is the population of autosomal recessive polycystic kidney disease?
Children.
What is the gene associated with autosomal recessive polycystic kidney disease?
PKHD1.
What is the gross pathology of autosomal recessive polycystic kidney disease?
Enlarged smooth kidneys with radially oriented cysts.
What causes mortality in autosomal recessive polycystic kidney disease?
Liver or kidney failure.
A patient with autosomal recessive polycystic kidney disease survives infancy. What complication are they likely to develop?
Liver cirrhosis.
Describe medullary sponge kidney.
Pretty harmless and associated with nephrolithiasis.
What is nephronophthisis?
A chronic renal disease that starts in kids.
What is the most common cause of end stage renal disease in kids and young adults?
Nephronophthisis-medullary cystic disease.
What is the gross pathology of nephronophthisis?
Cysts at corticomedullary junction.
What unique symptoms might be seen in nephronophthisis?
Polyuria and polydipsia; tubules can’t concentrate stuff, so we lose solutes, causing us to drink more water.
Describe the pain felt with passing renal stones.
“Renal colic” aka flank pain radiating to the groin.
What do renal stones predispose someone to?
Obstruction and infection.
What are the most common types of renal stones?
Calcium oxalate and calcium phosphate.
What is a unique cause of renal stones?
Struvite; associated with proteus infection.
What causes stone formation?
Hypercalciuria, magnesium ammonium phosphate (struvite), gout.
What are some acquired causes of outflow tract obstruction?
Stones, necrotic papillae, tumors, inflammation, pregnancy, neurogenic causes.
What is the pathophysiologic result of outflow tract obstruction?
Hydronephrosis aka dilation of renal pelvis and calyces.
What can happen to the fluid in outflow tract obstruction?
When it becomes stagnant it can become infected.
