Case Presentation: 73 year-old-woman with a past medical history of previous cholecystectomy presented with a one-day history of right upper quadrant pain, nausea, and vomiting. The patient denied taking any herbal supplements or any new medications. Physical exam was significant for right upper quadrant tenderness, without rebound or guarding. On admission, labs were significant for: alkaline phosphatase of 145 U/L, aspartate transaminase of 2671 U/L, alanine transaminase of 2249 U/L, and total bilirubin of 1.5 mg/dL. Patient developed a fever of 101.3°F on the first night of admission, infectious work-up was unrevealing. Her pain and fever resolved on hospital day 2. Patient’s evaluation for transaminitis was negative, including negative salicylate, acetaminophen, and ethanol levels and negative urine drug screen and autoimmune and viral hepatitis panels. MRCP showed 7mm filling defect at the distal common bile duct and subsequent ERCP showed main bile duct and cystic duct dilated up to 14mm. The cystic duct contained multiple filling defects consistent with stones. Patient had a sphincterotomy and one large cholesterol stone was removed. Based on these findings, the patient was diagnosed with Mirizzi Syndrome. Patient’s liver tests returned to normal limits and remained normal at her follow-up visit.
Discussion: Transaminase levels above 1000 U/L are historically considered virtually diagnostic of hepatic necrosis due to autoimmune or viral hepatitis, acute ischemia or drug toxicity, as opposed to a biliary etiology. Mirizzi Syndrome, a rare cause of biliary obstruction, is defined as common bile duct obstruction by external compression from an impacted stone in the cystic duct or infundibulum of the gallbladder. It classically presents with jaundice, fever and right upper quadrant abdominal pain. Elevated alkaline phosphatase and bilirubin are seen in over 90 percent of patients. Although this patient did have right upper quadrant pain and fever, she had a dramatic transaminitis instead of elevated alkaline phosphatase and bilirubin. Hepatocyte necrosis can be caused by bile-salts, which could explain this patient’s elevated transaminase levels. Definitive diagnosis of Mirizzi Syndrome is made by seeing one of the following on either ultrasound, CT, or MRCP: dilation of the biliary system about the gallbladder neck or in the common bile duct below the stone, and/or presence of a stone impacted in the gallbladder neck. Treatment is cholecystectomy or removal of impacted stone via ERCP. Mirizzi Syndrome does add an increase in risk of intraoperative biliary injury during cholecystectomy, making this dangerous to miss prior to biliary surgery.
Conclusions: Even though elevated transaminases are classically diagnostic of hepatic necrosis, in the correct clinical context, biliary ductal disease should be considered even with normal alkaline phosphatase and bilirubin.