Differential Diagnosis for a 35-year-old woman with vague upper abdominal pain post-cholecystectomy

Single most likely diagnosis

• Bile Duct Injury or Bile Leak: The patient's presentation with jaundice and mild right upper quadrant tenderness 7 days after cholecystectomy, along with elevated direct bilirubin and alkaline phosphatase, suggests a bile duct injury or leak. The ultrasound finding of minimal fluid in the gallbladder fossa supports this diagnosis, as it could indicate a collection of bile.

Other Likely diagnoses

• Hepatic Duct Stricture: This could be a complication of the cholecystectomy, leading to jaundice and elevated liver enzymes. The elevated alkaline phosphatase and direct bilirubin support this possibility.
• Residual Common Bile Duct Stones: Although the patient underwent cholecystectomy, it's possible that stones were left behind in the common bile duct, causing obstruction and leading to jaundice. The slightly dilated CBD (9 mm) on ultrasound could support this diagnosis.
• Postoperative Infection or Abscess: Although the patient's temperature is normal and the WBC count is within the normal range, a postoperative infection or abscess cannot be entirely ruled out, especially given the recent surgical history and the presence of mild right upper quadrant tenderness.

Do Not Miss (ddxs that may not be likely, but would be deadly if missed)

• Hemorrhage: Postoperative hemorrhage is a potentially life-threatening complication that must be considered, even though the patient's current presentation does not strongly suggest it. Any sign of instability or significant drop in hemoglobin would necessitate immediate investigation.
• Sepsis: Although the patient does not currently show signs of sepsis (normal temperature, WBC within normal limits), the possibility of an infected bile duct or abscess leading to sepsis must be considered, especially if the patient's condition deteriorates.

Rare diagnoses

• Primary Sclerosing Cholangitis: This is a chronic liver disease characterized by inflammation and scarring of the bile ducts inside and outside the liver. While it's rare and the patient's presentation is more suggestive of a post-surgical complication, it could be considered if other diagnoses are ruled out and the patient continues to have abnormal liver function tests.
• Recurrent Pyogenic Cholangitis: This condition involves recurrent infections of the bile duct and is more common in certain geographic regions. It would be an unusual diagnosis in this context but could be considered if the patient has risk factors or if other diagnoses are excluded.