Topic 74-80: vascular, ATN, tumors

Question 1

What are three vascular diseases of the kidney?

Answer 1

• benign nephrosclerosis (arterionephrosclerosis): associated with benign hypertension
• malignant nephrosclerosis: associated with malignant hypertension (BP > 200/120 mmHg)
• thrombotic microangiopathies: widespread thrombosis in microcirculation

Question 2

Benign nephrosclerosis is associated with what morphology?

Answer 2

• hyaline arteriolosclerosis
• diffuse granular kidney
• symmetrically atrophic

Question 3

malignant nephrosclerosis is associated with what morphology?

Answer 3

• fibrinoid necrosis
• hyperplastic arteriolosclerosis
• (possibly) pinpoint petechial hemorrhage, “flea-bitten” appearance

Question 4

Thrombotic angiopathies are what types of conditions?

Answer 4

• Hemolytic uremic syndrome (HUS) - toxins acting on endothelial cells
• thrombotic thrombocytopenic purpura (TTP) - vWF cleavage defect. cannot cleave vWF precursors -> extremely large vWF that increases platelet adherence and aggregation

Question 5

Diabetic nephropathy is characterized by two conditions:

These conditions are are associated with 3 lesions:

Answer 5

Characterized generally by nephrotic syndrome and diffuse glomerulonephritis

1. Glomerular lesions: BM thickening, Mesangial sclerosis, Kimmelstiel-Wilson
2. Renal vascular lesions, especially arteriolosclerosis (uniquely to DM: efferent arterioles are sclerotic)
3. Pyelonephritis, including necrotizing papillitis

Question 6

Glomerular lesions are what 3 things specifically with diabetic nephropathy?

Answer 6

• Glomerular BM thickening: thicker and porous
• Diffuse mesangial sclerosis: very common, mesangial cell proliferation
• Nodular glomerulosclerosis: PAS positive ball-like deposits in periphery of glomerulus (Kimmelstiel-Wilson lesion)

Question 7

Diabetic Nodular sclerosis is associated with ball like deposits called? How common are they?

Answer 7

• Kimmelstiel-wilson lesions

- not very common, only 15-30%

Question 8

What type of pyelonephritis is more common in diabetics?

Answer 8

-necrotizing papillitis is more prevalent in diabetics

Question 9

acute tubular necrosis is what? which parts of the tubule are affected? what are the three types of ATN?

Answer 9

ANT is damage to the tubular epithelial cells due to ischemia or toxins.

-the prox straight and thick ascending are the most affected

• Ischemic ATN
• nephrotoxic ATN
• pigment ATN

Question 10

ischemic ATN is due to what? what is the morphology/prognosis?

Answer 10

• ischemia due to shock

- fragmentation of the BM occurs, thus there is a worse prognosis

Question 11

Nephrotoxic ATN is due to what? prognosis?

Answer 11

• direct toxicity due to drugs such as aminoglycosides, heavy metals
• no BM fragmentation thus better prognosis
• only in proximal tubules!!

Question 12

pigment ATN is due to what? prognosis?

Answer 12

• hemoglobin (hemolysis) or myoglobin (crush syndrome, rhabdomyolysis) will cause pigment cast to form in the tubules that obstructs flow, causing plasma leaking into the interstitium and eventually increasing pressure so much that it causes tubular collapse

–damage of BM=bad prognosis

Question 13

Tubulointerstitial nephritis is what? what is the most common TIN infections? what are the specific types you should remember?

Answer 13

• an infection that involves the renal tubules and interstitium. the glomeruli are spared or only affected later
• usually caused by bacterial infections or interstitial inflam caused by drugs, physical injury, viruses, autoimmune, or metabolic disorders
• acute and chronic pyelonephritis
• acute drug-induced interstitial nephritis
• analgesic abuse nephritis
• urolithiasis

Question 14

What are the two types of chronic pyelonephritis?

Answer 14

• chronic obstructive - due to recurrent infections
• chronic reflux - most common due to the congenital vesicoureteral reflux! ureter doesn’t meet bladder at an angle and thus the urine goes back when voiding the bladder

Question 15

acute drug induced interstitial nephritis and analgesic abuse nephritis are different how?

Answer 15

• analgesic abuse nephritis is due to people who consume large quantities of painkillers or aspirin
• drug induced nephritis is a hypersensitivity rxn 1 or 4 to different types of drugs. symptoms occur about 2 weeks after administration and it’s because the drugs act as heptanes that bind the tubules and cause the hypersens rxn

Question 16

what are two types of renal obstruction

Answer 16

renal stones and hydronephros

Question 17

renal stones: how do they form and where? what are the consequences? what are the 4 types?

Answer 17

urolithiasis can form at any level of the urinary collection system but most arrive in the kidney. they for due to an increased concentration of the stones constituents in the urine leading to supersaturation –> precipitation
-consequences are pyelonephritis and hydronephrosis

• calcium stones
• Mg- ammonium phosphate stones (staghorn calculi)
• uric acid stones
• cystine stones

Question 18

hydronephrosis is what?

Answer 18

literally “water inside the kidney”—refers to distension and dilation of the renal pelvis and calyces, usually caused by urinary retention due to obstruction of the free flow of urine from the kidney

leads to atrophy

Question 19

What are the two types of benign renal cancer?

Answer 19

papillary adenoma and fibroma

Question 20

What are the three types of renal carcinomas? what cell do they derive from? who are they more likely to appear in?

Answer 20

all are derived from the renal tubular epithelium

-men are twice as likely and pts with PKD due to dialysis have a 30x chance inc of kidney cancer

• Clear cell carcinoma
• papillary renal cell carcinoma
• chromophobe renal carcinoma

Question 21

clear cell carcinoma is how common? occurs with what mutations or conditions?

Answer 21

• 70-80%!

- majority are sporatic but they can occur in assocatiion with von Hippel-lindau disease (VHL)

Question 22

papillary renal cell carcinoma is how common? how do they appear? occurs with what mutations or conditions?

Answer 22

• 10-15%
• frequently appear multifocal and bilateral!
• causative gene is the MET proto-oncogene on chrom 7 (tyrosine kinase receptor for hepatocyte growth factor). gene duplications or trisomy 7 will def cause cancer

Question 23

chromophobe renal carcinoma is how common? occurs with what mutations or conditions?

Answer 23

• 5%
• appear due to loss of entire chromosomes (can be 1,2,6,10,13,17,21)
• good prognosis

Question 24

what are the typical symptoms of renal carcinoma?

Answer 24

symptoms vary

• painless hematuria
• palpable abdominal mass
• dull flank pain

Question 25

renal cell carcinoma metastasis go where typically?

Answer 25

vertebra, lung, bone, liver, brain

Question 26

wilms tumor: how common is it? what is the cell origin? what gene mutations are common? what is the prognosis?

Answer 26

• third most common organ cancer in children under 10 years
• WT1 and WT2 are both tumor suppressor genes that are lost with tumor formation

the tumor originates from a variety of tissue components (all mesodermal) but there are two main forms

• epithelial cell -mimics tubules and glomerular structures
• stromal cell - mixed stroma with fibroblasts

generally the prognosis is excellent with treatment

Question 27

tumors of the bladder and ureter are important because? what are some predisposing factors? upon biopsy, what do they look for and why?

Answer 27

-bladder cancer is a more frequent cause of death than kidney cancer! and even a small lesion in the ureter can cause more serious problems that a large mass (due to obstruction)

• sex (men are 3x more likely)
• beta-naphthylamine (in cigarette smoke, 50X increased risk)
• cigarettes
• genetics via chrom 9 mutations

-depth of invasion is something very significant in bladder cancer biopsy analysis due to the increased risk of recurrence and worse prognosis

Question 28

what are the 3 types of bladder tumors?

Answer 28

• benign papilloma - frond like structure
• urothelial carcinoma - flat to papillary in shape, low to high grade, respectively
• in-situ stage of bladder cancer

think: Big Papa trump Urinates In the Situation room

Question 29

What is the clinical course of acute tubular injury? (3 stages)

Answer 29

1. Initiation: first 36 hours. Slight oliguria, BUN increase
2. Maintenance: 2-6 days. Dramatic drop in urine output. Develops uremia, acidosis, fluid overload, etc. Needs good hospital care to survive.
3. Recovery: Steady increase in urine volume, polyuria may develop. Plugs disappear from tubular system, epithelium regenerates. Still has risk of electrolyte imbalances and infection, and many still die in this phase.