What is the significance of elevated lipase and amylase (enzymes) in a pancreatic mass?

From the Guidelines

Elevated lipase and amylase levels in a pancreatic mass are highly suggestive of pancreatic inflammation or damage, and a lipase activity greater than twice the upper limit of normal is diagnostic of acute pancreatitis, as stated in the United Kingdom guidelines for the management of acute pancreatitis 1. The significance of these enzyme elevations lies in their ability to indicate pancreatic cell damage or obstruction, which can be caused by a variety of conditions, including pancreatitis or pancreatic cancer.

• The degree of elevation is crucial, with levels more than three times the upper limit of normal strongly suggesting acute pancreatitis.
• Lipase is generally more specific and sensitive for pancreatic disorders than amylase, which can also rise due to conditions affecting other organs, such as salivary gland disease or intestinal obstruction.
• The advantages of measuring lipase include its prolonged elevation compared to amylase and its high specificity due to the lack of other sources of lipase in the serum 1. Key considerations in interpreting these enzyme elevations include:
• Clinical symptoms, such as abdominal pain, nausea, and vomiting
• Imaging findings, such as ultrasound or CT scans, to visualize the pancreatic mass
• Other laboratory tests, such as tumor markers or blood counts, to determine the underlying cause of the pancreatic mass
• Persistent elevations over time, which may indicate ongoing pancreatic damage and can help monitor disease progression or treatment response.

From the Research

Significance of Elevated Lipase and Amylase in a Pancreatic Mass

• Elevated serum levels of lipase and amylase are often encountered in clinical practice, with a broad differential diagnosis that includes acute pancreatitis, chronic pancreatitis, gastrointestinal tract obstruction, malignancies, and other disease conditions 2.
• Lipase has largely replaced amylase in terms of diagnostic value, although both markers are still commonly used, with lipase offering a higher sensitivity than serum amylase in diagnosing acute pancreatitis 3, 4.
• The diagnostic benefits of lipase values in acute pancreatitis are well-established, with lipase being elevated for a longer time, thus allowing it to be a useful diagnostic biomarker in early and late stages of acute pancreatitis 3, 4.
• Elevated lipase and amylase levels can also be associated with pancreatic lesions, with a study finding significant elevation of lipase in 5% of cases and amylase in 2% of cases after puncture biopsy and fine needle aspiration guided by endoscopic ultrasound in pancreatic lesions 5.
• However, an elevated lipase should not be equated with evidence for pancreatitis if the amylase is normal, and a simultaneous determination of both amylase and lipase is recommended for the evaluation of patients with abdominal pain 6.

Diagnostic Considerations

• The use of lipase alone is sufficient for the diagnosis of acute pancreatitis, with several recent evidence-based guidelines recommending the use of lipase over amylase 4.
• Co-ordering of both lipase and amylase tests has shown little to no increase in diagnostic sensitivity and specificity, and unnecessary testing and laboratory expenditures can be reduced by testing lipase alone 4.
• Isolated elevation of lipase can be related to non-pancreatic sources of lipolytic enzymes, such as malignant tumors, renal insufficiency, or hypertriglyceridemia 6.