USMLE® Step 2 Question of the Day: Leukocytosis

Prepare for the USMLE Step 2 with a case of a 45-year-old woman presenting with right upper quadrant pain, fever, and a history of biliary colic. Learn how to identify key physical exam findings, such as a positive Murphy's sign, that suggest acute cholecystitis, a common complication of gallstones.

A 45-year-old woman presents to the primary care clinic with three days of right upper quadrant abdominal pain and fever. The patient has previously had three to four episodes of right upper quadrant pain, occasionally with vomiting, that were worse after eating and resolved within two to three hours. Vital signs include temperature of 38.6 ºC (101.5 ºF), heart rate of 108/min, blood pressure of 140/75 mmHg, respiratory rate of 18/min, and SpO2 of 100% on room air. The patient is sent to the emergency department for bloodwork and imaging. Bloodwork shows leukocytosis. Which of the following findings on physical exam would be most suggestive of the underlying diagnosis? 

A. Positive Murphy sign 

B. Tenderness at McBurney point

C. Positive Rovsing sign

D. Positive Courvoisier sign

E. Epigastric tenderness to palpation

Scroll down for the correct answer!

The correct answer to today's USMLE® Step 2 CK Question is...

A. Positive Murphy sign 

Before we get to the Main Explanation, let's see why the answer wasn't B, C, D, or E. Skip to the bottom if you want to see the correct answer right away!

Incorrect answer explanations

Today's incorrect answers are...

B. Tenderness at McBurney point

Incorrect:Tenderness at McBurney point, which is 1.5 to 2 inches from the anterior superior iliac spine on a straight line to the umbilicus, is indicative of acute appendicitis not acute cholecystitis.

C. Positive Rovsing sign 

Incorrect: The patient most likely has a cough secondary to bronchial irritation caused by bradykinin accumulation. The best step is to discontinue the causative medication. A chest x-ray is not indicated at this time.

D. Positive Courvoisier sign  

Incorrect: A positive Courvoisier sign is a palpable gallbladder in the presence of jaundice. This is most suggestive of pancreatic or gallbladder malignancy, not acute cholecystitis. 

E. Epigastric tenderness to palpation

Incorrect: Both epigastric and right upper quadrant tenderness can be seen on physical exam in acute cholecystitis. However epigastric tenderness can also be seen in other conditions such as pancreatitis and peptic ulcer disease. 

Main Explanation

This patient has a history of three to four episodes of biliary colic, usually described as intense right upper quadrant abdominal pain that is typically constant and caused by gallstones. The pain typically occurs when the biliary duct contracts on an impacted gallstone–often set off by eating, especially fatty foods, with increased pressure within the gallbladder. Patients often report associated nausea and vomiting.  

Acute cholecystitis presenting as fever, right upper quadrant pain, and leukocytosis can develop as a complication of gallstones from gallbladder inflammation. Physical examination will show right upper quadrant tenderness to palpation or epigastric tenderness. A positive Murphy sign is highly suggestive of acute cholecystitis. It is tested for by palpating the gallbladder during deep inspiration and is considered positive if the pain significantly worsens or if the patient stops inspiring because of the pain. 

Abdominal ultrasound should be performed when acute cholecystitis is suspected. The gallbladder will appear distended and thickened with surrounding edema and gallstones may be seen. Acute cholecystitis can be definitively diagnosed in the right clinical setting with demonstration of gallbladder wall thickening or edema on imaging, a sonographic Murphy sign, or failure of the gallbladder to fill during cholescintigraphy.  

Major takeaway

Patients with a prior history of biliary colic from gallstones who present with fever, right upper quadrant abdominal pain, and leukocytosis should be evaluated for acute cholecystitis. A positive Murphy sign on physical exam is highly suggestive of acute cholecystitis.  

References

Baiu I, Hawn MT. Gallstones and Biliary Colic. JAMA. 2018 Oct 16;320(15):1612. doi: 10.1001/jama.2018.11868. PMID: 30326127. 

Kiewiet JJ, Leeuwenburgh MM, Bipat S, Bossuyt PM, Stoker J, Boermeester MA. A systematic review and meta-analysis of diagnostic performance of imaging in acute cholecystitis. Radiology. 2012 Sep;264(3):708-20. doi: 10.1148/radiol.12111561. Epub 2012 Jul 12. PMID: 22798223. 

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