Nephrolithiasis

Question 1

A 35 year old male presents with severe flank pain radiating to the groin. It comes in waves. He can’t get into a comfortable position. He has positive CVA tenderness. No fevers or chills. UA shows RBCs but no WBC. What is the diagnosis?

Answer 1

Obstructive nephrolithiasis

Question 2

What is the stone most likely made of?

Answer 2

Calcium (oxalate of phosphate)

Question 3

What is the best imaging modality to make a diagnosis?

Answer 3

Non-contrast abdominal CT (stone protocol)

Question 4

What is the best initial imaging modality for a young child with suspected obstructive stone?

Answer 4

Renal ultrasound

Question 5

What size stone is unlikely to pass in an adult?

Answer 5

> 5mm

Question 6

What is the likely procedure performed for obstructive kidney stones that are not able to pass?

Answer 6

Shock wave lithotripsy (and stent placement)

Question 7

A 65 year old male with a history of 50pkyr cigarette smoking presents with blood in the urine. He denies fever or pain anywhere. Name three differential diagnoses.

Answer 7

1. Bladder cancer -
2. Renal cell cancer -
3. Nephrolithiasis - unlikely without pain but possible
4. Urinary tract infection - further work up required.

Question 8

What is the best diagnostic study to determine if the patient has bladder cancer?

Answer 8

Cystoscopy with biopsy

Question 9

What is the diagnostic method of choice to diagnose renal cell cancer?

Answer 9

CT with contrast