Renal - Pathology (Kidney stones & Hydronephrosis)

Question 1

What complications can kidney stones cause?

Answer 1

Can lead to severe complications, such as hydronephrosis and pyelonephritis.

Question 2

How do kidney stones present?

Answer 2

Presents with unilateral flank tenderness, colicky pain radiating to groin, and hematuria.

Question 3

How are kidney stones managed?

Answer 3

Treat and prevent by encouraging fluid intake.

Question 4

What are 4 different kinds of kidney stones? What percentage of kidney stones is each?

Answer 4

(1) Calcium (80%) (2) Ammonium magnesium phosphate (15%) (3) Uric acid (5%) (4) Cystine (1%)

Question 5

At what pH do each of the following kinds of kidney stones precipitate: (1) Calcium (2) Ammonium magnesium phosphate (3) Uric acid (4) Cystine?

Answer 5

(1) Precipitates at high pH (calcium phosphate) and low pH (calcium oxalate) (2) Precipitates at high pH (3) Precipitates at low pH (4) Precipitates at low pH

Question 6

What are the X-ray findings for the following types of kidney stones: (1) Calcium (2) Ammonium magnesium phosphate (3) Uric acid (4) Cystine.

Answer 6

(1) Radiopaque (2) Radiopaque (3) Radiolucent (4) Radiopaque

Question 7

What kind of urine crystals are seen for each of the following kidney stones: (1) Calcium (2) Ammonium magnesium phosphate (3) Uric acid (4) Cystine?

Answer 7

(1) Envelope or dumbbell shaped (2) Coffin lid (3) Rhomboid or rosettes (4) Hexagonal

Question 8

What compounds form calcium kidney stones?

Answer 8

Calcium oxalate, calcium phosphate, or both.

Question 9

What promotes calcium kidney stones? Give examples of this.

Answer 9

Promoted by hypercalciuria (idiopathic or secondary to conditions that cause hypercalcemia, such as cancer and increased PTH)

Question 10

From what can oxalate crystals result?

Answer 10

Oxalate crystals can result from ethylene glycol (antifreeze), vitamin C abuse, or Crohn disease.

Question 11

What are the treatments for recurrent calcium stones?

Answer 11

Treatments for recurrent stones include thiazides and citrate.

Question 12

What is the most common kidney stone presentation?

Answer 12

Most common kidney stone presentation: calcium oxalate stone in a patient with hypercalciuria and normocalcemia.

Question 13

What is another name for ammonium magnesium phosphate kidney stones?

Answer 13

Also known as struvite.

Question 14

What causes ammonium magnesium phosphate kidney stones?

Answer 14

Caused by infection with urease (+) bugs (Proteus mirabilis, Staphylococcus, Klebsiella) that hydrolyze urea to ammonia –> urine alkalinization.

Question 15

How are ammonium magnesium phosphate kidney stones related to UTIs?

Answer 15

Can form staghorn calculi that can be a nidus for UTIs.

Question 16

What is the treatment for ammonium magnesium phosphate kidney stones?

Answer 16

Treatment: eradication of underlying infection and surgical removal of stone.

Question 17

What are the risk factors of uric acid kidney stones?

Answer 17

Risk factors: decreased urine volume, arid climates, and acidic pH.

Question 18

Through what imaging modalities are uric acid kidney stones visible versus not visible?

Answer 18

Visible on CT and ultrasound, but not x-ray.

Question 19

With what do uric acid kidney stones have a strong association?

Answer 19

Strong association with hyperuricemia (e.g., gout).

Question 20

In what kind of diseases are uric acid kidney stones seen? Give an example of such a disease.

Answer 20

Often seen in diseases with increased cell turnover, such as leukemia.

Question 21

What is the treatment for uric acid kidney stones?

Answer 21

Treatment: alkalinization of urine.

Question 22

In what patient population and/or clinical context are cystine kidney stones mostly seen?

Answer 22

Mostly seen in children, secondary to cystinuria.

Question 23

Which types of kidney stones can form staghorn calculi?

Answer 23

Ammonium magnesium phosphate & Cystine

Question 24

What test is positive in the case of cystine kidney stones?

Answer 24

Sodium nitroprusside test (+).

Question 25

What is the treatment for cystine kidney stones?

Answer 25

Treatment: alkalinization of urine and hydration

Question 26

What is hydronephrosis?

Answer 26

Distention/dilation of the renal pelvis and calyces.

Question 27

What are causes of hydronephrosis?

Answer 27

Usually caused by urinary tract obstruction (e.g., renal stones, BPH, cervical cancer, injury to ureter); other causes include retroperitoneal fibrosis and vesicoureteral reflux.

Question 28

In hydronephrosis, where does dilation occur?

Answer 28

Dilation occurs proximal to site of pathology.

Question 29

Under what conditions does hydronephrosis impair renal function?

Answer 29

Only impairs renal function if bilateral or patient only has one kidney.

Question 30

What is a consequence of hydronephrosis?

Answer 30

Leads to compression atrophy of renal cortex and medulla.