Mild forms of chronic pancreatitis is difficult to diagnose, hence a combination of tests are required. Estimation of serum amylase and lipase as in acute pancreatitis is usually not helpful in this case.
Chronic Pancreatic Function Test
- Secretin- pancreozymin test is the gold standard test for chronic pancreatitis.
- It involves estimation of volume, bicarbonate and enzyme secretion in duodenal aspirate after injection of secretin and pancreozymes.
- In chronic pancreatitis all these parameters will be reduced.
- Tubeless pancreatitis function test.
- This includes the NBT-PABA test and pancreolauryl test.
- These are good screening tests for advanced form of disease.
Diagnostic Tests For Chronic Pancreatitis
Mainstay of diagnosis is imaging studies.
- X-ray abdomen – Demonstration of pancreatic calculi on plain X-ray of abdomen is conclusive of chronic pancreatitis. Calculi are demonstrable in about 30% alcoholic and 60 to 90% of cases of tropical pancreatitis.
- USG – It demonstrates ductal dilation, parenchymal changes like enlargement or atrophy, presence of pseudo cyst and tumor.
- CT-scan – It is more sensitive in demonstrating calculi and small mass lesions missed by USG. Role of MRI in chronic pancreatitis is yet not established.
- ERCP – It is helpful in planning surgery by delineating the ductal morphology. Ductal changes like stricture dilatation and block are demonstrated.
Segmental dilatation of main pancreatic duct gives rise to classical “chain of lakes” appearance.
Intra-ductal calculi and communicating cysts are well delineated.
Presence of a mass lesion on USG and CT-scan with ductal block on ERCP is suggestive of pancreatic cancer.
ERCP is also helpful in delineating biliary obstruction and for therapeutic interventions.
- Endoscopy – USG is a new imaging modality giving close details of the morphological changes and is especially helpful in pre-operative assessments of cysts and tumor.
- C. Estimation of tumor markers like CA-19-9 and carcinoembryogenic antigen (CEA) is done when malignancy is suspected, but their sensitivity and specificity are not high.