Chapter 19- The Pancreas Flashcards
What are the two components of the pancreas and what cells are the made up of?
- Exocrine- acinar cells
2. Endocrine- islets of Langerhans
What congenital anomalies can affect the pancreas?
Pancreas divisum- failure of duct system fusion
Annular pancreas- ring of normal pancreas encircling the duodenum (ventral buds split)
Ectopic pancreas
Agenesis
What is the most common pancreatic congenital anomaly?
Pancreas divisum
Where are ectopic pancreases most commonly found?
Stomach > duodenum > jejunum
What is the cause of pancreatitis?
Autodigestion by pancreatic enzymes
What are the two primary causes of acute pancreatitis?
Biliary tract disease (obstruction- gallstones)
Alcoholism
What is the pathology of acute pancreatitis?
Inappropriate release and activation of enzymes
Inflammation and thrombosis damage acinar cells and increase enzyme activation (enzymes are released when cells are damaged)
How does alcoholism cause pancreatitis?
CYTP450 receptors are found on the ducts epithelium
Targeted by acetaldehyde
What are the effects of acute pancreatitis?
Edema
Inflammation
Fat necrosis
Proteolysis
Hemorrhage
What differentiates chronic and acute pancreatitis?
Chronic- irreversible parenchymal destruction and fibrosis
Acute- damage is reversible
What can cause chronic pancreatitis?
Repeated bouts of acute pancreatitis
Long term alcohol abuse
Long standing obstruction
Autoimmune disorder
Hereditary syndromes
What is the morphology of chronic pancreatitis?
Dense, fibrous tissue
Islets spared until late stages
What can chronic pancreatitis lead to?
Malabsorption
Diabetes mellitus
Psuedocysts
What are the two forms of nonneoplastic pancreatic cysts?
- Congenital
2. Psuedocysts
What is the morphology of pancreatic congenital cysts?
Unilocular, thin walled with cuboidal epithelium
What causes congenital cysts in the pancreas?
Abnormal pancreatic duct development
Polycystic kidney disease
Von Hippel-Lindau disease
What are pancreatic pseudocysts?
Cystic collections of necrotic, hemorrhagic material
No epithelium
What is the most common form of pancreatic cysts?
Pseudocysts
What types of pancreatitis can develop psuedocysts?
Acute and chronic
What are the different forms of pancreatic cystic neoplasms and where are they located?
- Serous- pancreatic tail
- Mucinous- pancreatic rail
- Intraductal papillary mucinous neoplasms (IPMNs)- head of pancreas
- Solid pseudopapillary tumour
What is the characteristic architecture of serous pancreatic cysts?
Microcystic/spongey
What kind of fluid is in serous pancreatic cysts?
Watery/transparent
Are serous cysts more often benign or malignant?
Benign
What epithelial type is present in serous pancreatic cysts?
Cuboidal
What is the morphology of mucinous pancreatic cysts?
Multiloculated
Mucin-producing columnar cells
Multicystic cut surface
One third of mucinous pancreatic cysts harbour what form of cancer?
Invasive adenocarcinoma
What is the morphology of IPMNs?
Dilated ducts with papillae
What can IPMNs progress to?
Invasive cancer
What is the morphology of solid pseudopapillary tumours of the pancreas?
Round, well circumscribed with solid and cystic areas
Large size
What is curative for solid pseudopapillary tumours?
Complete resection
What precursor lesion is believed to cause pancreatic carcinoma?
Pancreatic intraepithelial neoplasia (PanIN)
What is PanIN?
Well defined, no invasive lesion of the pancreatic ducts
What is a Whipple procedure?
Removal of the head of the pancreas and part of the duodenum
Where are the majority of pancreatic carcinomas found?
Head > diffuse > body > tail
What kind of response do pancreatic carcinomas elicit?
Strong desmoplastic response (intense surrounding fibrosis)
How can cancers in the head of the pancreas cause jaundice?
Obstruct duct
Pancreatic cancers in what location can remain clinically silent?
Body and tail
What syndrome can occur in pancreatic carcinoma?
Trousseau
Where do the majority of acinar cell carcinomas occur?
Head > tail > body
What is the morphology of acinar cell carcinoma?
Solid, fleshy, circumscribed
What type of component is found in 40% of acinar cell carcinomas?
Endocrine
Pancreatoblastoma is found in what type of patient?
Children
What is the morphology of pancreatoblastoma?
Squamous islands, mixed with acinar cells
How do insulin producing tumours and other neuroendocrine tumours of the pancreas differ?
Insulin producing- 90% benign
Other- 60-90% malignant
What is the most common neuroendocrine tumour of the pancreas?
Insulin producing
What is the morphology of pancreatic endocrine tumours?
Less than 2cm
Encapsulated/sharply circumscribed
Pale-red/brown
