Medical Student Clinical Pearl by Thomas Camp
MD Candidate, Class of 2024
Dalhousie University
Reviewed by Dr. J Vonkeman
Copy Edited by Dr. J Vonkeman
Pdf Download: EMSJ Pancreatic Pseudocysts: An Uncommon Cause of Painless Jaundice
Introduction
It’s 6:30 pm on a Monday evening, and a 52-year-old man presents to the ER with overt jaundice. He says that he’s been feeling great and that he only came in because his coworkers have been teasing him about his changing skin colour.
History and Physical
The patient reports that his skin has been turning yellow for the past week. He denies abdominal pain, nausea, vomiting, weight loss, fever, and fatigue. He also denies any pruritus, bruising, gastrointestinal bleeding, abdominal distension, or mental status changes. On further questioning, he reveals that his stool was pale this morning and that his urine has been unusually dark. Last year he was admitted to hospital for acute pancreatitis, which was thought to be induced by heavy alcohol consumption.
He is unaware of any other medical conditions and does not take any regular medications or herbal supplements. The patient denies any alcohol consumption since his previous admission, any history of IV drug use, and any history of international travel or blood transfusions. He smokes two packs of cigarettes per and there is an extensive family history of gastric cancer.
Physical examination reveals a thin, overtly jaundiced man with scleral icterus and a strong scent of tobacco. His lungs are clear, and his heart sounds are normal. His abdomen is soft and nontender, and there is no evidence of organomegaly or extra hepatic manifestations of liver disease (Figure 1). Ultrasound reveals a distended gallbladder and biliary tree without stones.
Approach to Jaundice
Jaundice is the result of excessive bilirubin levels in the blood, and bilirubin is a product of heme catabolism.2 The differential diagnosis for jaundice is broad but, conceptually, can be divided into pre-hepatic, intra-hepatic, and post-hepatic causes (Figure 2).3
- Pre-hepatic jaundice is the result of excessive unconjugated bilirubin production, which overwhelms the liver’s ability to conjugate it for excretion. Hemolysis is the most common cause of pre-hepatic jaundice.
- Intra-hepatic jaundice is the result of either decreased bilirubin uptake or impaired bilirubin conjugation within the liver’s hepatocytes,4 leading to impaired secretion in the bile. Common causes include viral hepatitis, drug toxicity, alcoholic hepatitis, and any of the many conditions leading to cirrhosis.
- Post-hepatic jaundice is the result of biliary obstruction, which impairs the flow of bile into the duodenum. Gallstones and cancer are the most common cause, but pancreatic pseudocysts, primary sclerosing cholangitis, and bile duct strictures are also possible etiologies.
The distention of the biliary tree, the presence of acholic stools, and dark urine suggests post-hepatic jaundice in this patient. These are characteristic findings of post-hepatic jaundice because the lack of bilirubin entering the duodenum results in pale stools, and at the same time conjugated bilirubin is water soluble, giving urine a dark colour.3 His age, sex, smoking status, and family history are also significant risk factors for pancreatic cancer, which commonly presents with jaundice.5
Work Up
Laboratory investigations reveal conjugated hyperbilirubinemia with a large increase in ALP and a mild increase in ALT. This is a cholestatic pattern of liver injury, which is characterized by a fourfold or greater increase in ALP and absent or mild elevations in the aminotransferases.6,7 In contrast, a hepatocellular pattern of liver injury is characterized by elevated aminotransferases and normal or mildly elevated ALP.6,7
INR and albumin levels are normal, suggesting that synthetic liver function is preserved. Normal hemoglobin levels (that are also stable when compared to the patient’s historical baseline) help exclude hemolysis from the differential. Elevated lipase is worrying for pancreatic cancer but could be explained by obstruction of the pancreatic duct by another cause, for example, gallstones not appreciated on ultrasound.
An urgent CT scan is ordered, and the radiologist comments that there is a complex cystic mass arising from the head of the pancreas that is causing obstruction of the common bile and pancreatic ducts. He notes that underlying malignancy cannot be excluded, and endoscopic retrograde cholangiopancreatography (ERCP) is recommended for further investigation. The patient is referred to gastroenterology and discharged home.
Conclusion
A week later, ERCP confirms that the mass is in fact a pancreatic pseudocyst. Pancreatic pseudocysts are collections of fluid with a well-defined wall that lack the epithelium required to be classified as true cysts. Classically, they form after an episode of acute pancreatitis, but they are also seen in chronic pancreatitis, in obstruction of the pancreatic duct, and after pancreatic trauma.8 The cyst is drained endoscopically, a technique that is now considered preferable to a percutaneous approach due to its excellent rates of resolution (82-94%).9 The patient’s jaundice resolves over the following weeks and repeat laboratory investigations normalize within two months.
Key Points
- Categorizing jaundice as pre-hepatic, intra-hepatic, or post-hepatic can provide a useful framework for formulating a differential diagnosis.
- A fourfold or greater increase in ALP with mild or no elevation in the aminotransferases is characteristic of post-hepatic jaundice.
- Consider pancreatic pseudocysts in patients presenting with post-hepatic jaundice, especially if they have a recent history of acute pancreatitis.
References
- Scott L Friedman M. Clinical manifestations and diagnosis of alcohol-associated fatty liver disease and cirrhosis. In: Post TW, ed. UpToDate. Wolters Kluwer; 2023. https://www.uptodate.com/contents/clinical-manifestations-and-diagnosis-of-alcohol-associated-fatty-liver-disease-and-cirrhosis
- John S, Pratt DS. Jaundice. In: Loscalzo J, Fauci A, Kasper D, Hauser S, Longo D, Jameson JL, eds. Harrison’s Principles of Internal Medicine, 21e. McGraw-Hill Education; 2022. http://accessmedicine.mhmedical.com/content.aspx?aid=1197684641
- Beckingham IJ, Ryder SD. ABC of diseases of liver, pancreas, and biliary system. Investigation of liver and biliary disease. BMJ. 2001;322(7277):33-36. doi:10.1136/bmj.322.7277.33
- Wolkoff AW. The Hyperbilirubinemias. In: Loscalzo J, Fauci A, Kasper D, Hauser S, Longo D, Jameson JL, eds. Harrison’s Principles of Internal Medicine, 21e. McGraw-Hill Education; 2022. http://accessmedicine.mhmedical.com/content.aspx?aid=1190492793
- Freelove R, Walling AD. Pancreatic cancer: Diagnosis and management. Am Fam Physician. 2006;73(3).
- Moseley RH. EVALUATION OF ABNORMAL LIVER FUNCTION TESTS. Medical Clinics of North America. 1996;80(5):887-906. doi:https://doi.org/10.1016/S0025-7125(05)70472-7
- Bethea ED, Pratt DS. Evaluation of Liver Function. In: Loscalzo J, Fauci A, Kasper D, Hauser S, Longo D, Jameson JL, eds. Harrison’s Principles of Internal Medicine, 21e. McGraw-Hill Education; 2022. http://accessmedicine.mhmedical.com/content.aspx?aid=1190492731
- Habashi S, Draganov P V. Pancreatic pseudocyst. World J Gastroenterol. 2009;15(1):38-47. doi:10.3748/wjg.15.38
- Piraka C, Chen YK. Pseudocyst Drainage: ERCP and EUS Approaches. Tech Gastrointest Endosc. 2007;9(3). doi:10.1016/j.tgie.2007.05.002