CA 19-9 (carbohydrate antigen 19-9) is a specific tumour marker.
It is primarily used in the diagnosis and monitoring of pancreatic cancer.
While elevated CA 19-9 levels can be found in other gastrointestinal cancers and non-cancerous conditions, its strongest clinical association remains with pancreatic cancer.
Consequently, CA 19-9 is a key diagnostic indicator for pancreatic cancer.
'Chain of Lakes' appearance due to sacculation with intervening short strictures of pancreatic duct is seen on: