1. Chapter 19 The Pancreas

2. Pancreas
Transversely oriented retroperitoneal organ extending from the C loop of the duedenum to the hilum of the spleen
Head, neck, body, tail
Pancreatic duct system is highly variable
80-85% exocrine
Self-digestion is prevented by several mechanisms

3. Congenital anomalies Agenesis Pancreas Divisum Annular pancreas
Ectopic pancreas

4. Pancreatitis
Inflammation in the pancreas associated with injury to the exocrine pancreas
Acute
reversible injury associated with inflammation
bilary tract disease and alcoholism- 80%
less common – obstruction of the duct system, medications, infections, metabolic disorders, ischemic injury, trauma, inherited alterations in genes encoding pancreatic enzymes and their inhibitors
mutations in the cationic trypsinogen gene or the gene for the trypsin inhibitor

5. Acute pancreatitis Microvascular leakage causing edema
Necrosis of fat by lipolytic enzymes
Acute inflammation
Proteolytic destruction of parenchyma
Destruction of blood vessels and hemorrhage
Acute necrotizing or hemorrhagic
Autodigestion of the pancreatic substance by inappropriately activated pancreatic enzymes
Trypsinogen
Three possible causes of activation
duct obstruction
acinar cell injury
defective intracellular transport
Clinical features
abdominal pain-constant
anorexia, NV,
systemic symptoms related to release of toxic enzymes, cytokines, medicators – explosive activaiton of the inflammatory response
amylase, lipase
resting the pancreas

6. Chronic Pancreatitis
Inflammation with irreversible destruction of exocrine parenchyma, fibrosis, and later destruction of the endocrine parenchyma
Long-term alcohol abuse is most common cause
Other causes
obstruction
tropical
hereditary CF
Pathogenesis
ductal obstructions by concretions
toxic effects
oxidative stress
Parenchymal fibrosis, reduced number and size of acini with relative sparing of the islets of Lngerhans and variable dilation of the pancreatic ducts
Lymphoplasmactic sclerosing pancreatitis ( auto-immune)
Clinical features
variable recurrent attacks of pain, persistent abdominal and back pain
triggers- alcohol abuse, overeating, drugs

7. Non-neoplastic Cysts Congenital polycytic disease
von Hippel-Lindau disease
Pseudocysts
localized collections of necrotic-hemorrhagic material rich in pancreatic enzymes
No epithelial lining

8. Cystic neoplasms Serous cystadenomas Mucinous cystic neoplasms
Intraductal papillary muinous neoplasms
Solid-pseudopapillary neoplasm

9. Pancreatic Carcinoma Infiltrating ductal adenocarcinoma
Fourth leading cause of caner deaths in the US
Precursor – pancreatic intraepithelial neoplasms
Cigarette smoking
Chronic pancreatitis
Diabetes mellitus
Elderly
Familial clustering
Carcinomas of the body and tail of the pancreas do not impinge on the biliary tract and hence remain silent for some time
Moderately to poorly differentiated adenocarcinoma forming abortive tubular structures or cell clusters and slowing an aggressive, deeply infiltrative growth pattern
Often remain silent until they invade into adjacent structures
Trousseau sign – migratory thrombophlebitis
Acinar cell carcinoma
pancreatoblastoma