An Osmosis USMLE® Step 2 CK-style clinically-focused practice question to test your medical knowledge. Today’s case involves a 68-year-old woman presenting with acute left back pain and hematuria. Which historical or physical exam finding would best support the diagnosis?
A 68-year-old woman presents to the emergency department for evaluation of acute onset left back pain and hematuria. The patient states that since the early morning, she has been having intense pain in the left mid-back that comes in waves. She has no nausea or vomiting. Past medical history includes hypertension, for which she takes amlodipine. The patient is currently in pain. Urinalysis findings are shown below. Non-contrast helical CT scan of the abdomen and pelvis demonstrates a 2 mm obstructing stone mid-ureter on the left.
| Laboratory value | Result |
| Urinalysis | |
| Color | Clear |
| Specific gravity | 1.013 |
| Glucose | Negative |
| Blood | Large |
| Leukocyte esterase | Negative |
| Nitrites | Negative |
| Leukocytes | 1-2/hpf |
| Erythrocytes | 25-50/hpf |
| Dysmorphic RBCs | Absent |
| Casts | None |
Which of the following historical or physical exam findings would be most consistent with the underlying diagnosis?
A. Left flank tenderness
B. Suprapubic tenderness
C. High fever
D. Bradycardia
E. Abdominal distension
Scroll down for the correct answer!
The correct answer to today’s USMLE® Step 1 Question is…
A. Left flank tenderness
Correct: See Main Explanation.
Incorrect Answer Explanations
B. Suprapubic tenderness
Incorrect: Suprapubic tenderness is typically suggestive of bladder inflammation or other lower urinary tract pathology, such as cystitis. This patient’s urinalysis is not indicative of an infection, and CT shows a left kidney stone.
C. High fever
Incorrect: Fever can be seen with renal stones; it typically indicates pyelonephritis or infection of the kidney, which can be a complication of renal stones. However, there is no infection evident on urinalysis, and there is no evidence of pyelonephritis on CT.
D. Bradycardia
Incorrect: Bradycardia is not typically associated with nephrolithiasis. Tachycardia is more likely to be seen as a consequence of pain.
E. Abdominal distension
Incorrect: Abdominal distention is not a typical finding in nephrolithiasis. However, it may be seen if there is associated nausea and vomiting, which this patient does not have.
Main Explanation
This patient presents with symptoms and urinalysis findings that are concerning for nephrolithiasis, which is confirmed with a non-contrast helical CT scan of the abdomen and pelvis that shows a renal stone on the left. Left flank (or costovertebral angle) tenderness would be an expected physical examination finding.
Nephrolithiasis, also known as renal calculi or renal (or kidney) stones, is a painful condition where crystals form in the kidney that potentially leads to urinary tract obstruction. Renal stones usually form when urine becomes oversaturated with minerals and salts, including calcium, oxalate, and uric acid. Common renal stone types include calcium oxalate-, calcium phosphate-, uric acid-, cystine-, and struvite stones. Patients classically present with the acute onset of flank pain, which may radiate to the groin. Patients may have associated hematuria, dysuria urgency, nausea, and vomiting. Physical examination may reveal unilateral flank or costovertebral angle tenderness. Patients often appear uncomfortable from the pain.
Major Takeaway
Unilateral flank pain and tenderness are typically seen in patients presenting with nephrolithiasis.
Want to learn more about this topic?
Watch the Osmosis video: Nephrolithiasis
References
- (2014) Guideline for medical management of kidney stones. AUA. https://doi.org/10.1016/j.juro.2014.05.006
- Pearle MS, Goldfarb DS, Assimos DG, et al. Medical management of kidney stones: AUA guideline. J Urol. 2014;192(2):316-324. https://doi.org/10.1016/j.juro.2014.05.006
- Fontenelle LF, Sarti TD. Kidney Stones: Treatment and Prevention. Am Fam Physician. 2019;99(8):490-496.
- Jameson J, Fauci AS, Kasper DL, Hauser SL, Longo DL, Loscalzo J. eds. Harrison’s Principles of Internal Medicine, 20e. McGraw Hill; 2018.
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