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HelpTest Code AMLPC Amylase, Pancreatic Cyst Fluid
Reporting Name
Amylase, Pancreatic CystUseful For
Aiding in distinguishing between pseudocysts and other types of pancreatic cysts when used in conjunction with imaging studies, cytology, and other pancreatic cyst fluid tumor markers
Method Name
Substrate Kinetic
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Pancreatic Cyst FluidOrdering Guidance
For other body fluid specimens (eg, peritoneal, pleural), order AMBF / Amylase, Body Fluid. Testing will be changed to AMBF if this test is ordered on any fluid other than pancreatic fluid.
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Container/Tube: Plain vial
Specimen Volume: 1 mL
Additional Information: A minimum of 0.5 mL is required for testing; specimens less than 0.5 mL may be rejected.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Pancreatic Cyst Fluid | Frozen (preferred) | 30 days | |
| Ambient | 7 days | ||
| Refrigerated | 7 days |
Reject Due To
| Gross hemolysis | Reject |
Reference Values
An interpretive report will be provided.
Day(s) Performed
Monday through Saturday
CPT Code Information
82150
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| AMLPC | Amylase, Pancreatic Cyst | 48996-3 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| AMYPC | Amylase, Pancreatic Cyst | 48996-3 |
| SITE6 | Site | 39111-0 |
Clinical Information
Amylases are a group of hydrolases that degrade complex carbohydrates into fragments. Amylase is produced by the exocrine pancreas and the salivary glands to aid in the digestion of starch. It is also produced by the small intestine mucosa, ovaries, placenta, liver, and fallopian tubes.
Measurement of amylase in pancreatic cyst fluid is often used in conjunction with tumor markers carcinoembryonic antigen, and CA19-9 as an aid in the differential diagnosis of pancreatic cysts lesions. Amylase seems to be particularly helpful in excluding pancreatic pseudocysts. A number of studies have demonstrated that amylase levels are typically very high, usually in the thousands in pseudocysts, therefore, low amylase values virtually exclude pseudocysts. Based on the evidence available, the American College of Gastroenterology practice guidelines for the Diagnosis and Management of Neoplastic Pancreatic Cysts suggest that an amylase cutoff value of 250 U/L is useful to exclude pseudocysts.
Interpretation
A pancreatic cyst fluid amylase concentration of less than 250 U/L indicates a low risk of a pseudocyst and is more consistent with cystic neoplasms such as mucinous cystic neoplasms (MCN), intraductal papillary mucinous neoplasm (IPMN), serous cystadenomas, cystic neuroendocrine tumor, and mucinous cystadenocarcinoma. High pancreatic cyst fluid amylase values are nonspecific and occur both in pseudocysts and some mucin-producing cystic neoplasms including MCN, IPMN, and mucinous cystadenocarcinoma.
In-house studies showed that using a cutoff value of less than 250 U/L to exclude a pseudocyst has 94% sensitivity and 42% specificity. Cysts with amylase levels of less than 250 U/L included 69% of adenocarcinomas, 31% of intraductal papillary mucinous neoplasia, 55% of mucinous cystadenomas, 64% serous cystadenomas, and 6% of pseudocysts.
Cautions
This test result should not be the sole basis for diagnosis. Test results should always be correlated with imaging and cytology.
Method Description
The Roche amylase method is an enzymatic colorimetric test using 4,6-ethylidene (G7)-p-nitrophenol (G1)-alpha, D-maltoheptaoside (ethylidene-G7PNP) as a substrate. Human salivary and pancreatic amylases (alpha-amylase) convert the substrate at approximately the same rate. The alpha-amylase cleaves the substrate into G2, G3, G4 p-nitrophenol (PNP) fragments. The G2, G3, and G4 PNP fragments are further hydrolyzed by an alpha-glucosidase to yield PNP and glucose. The rate of increase in absorbance at 415 nm (measuring the increase in PNP) is directly proportional to amylase activity.(Package insert: Roche AMYL2 reagent. Roche Diagnostic Corp; V10 12/2018)