Nelson: Pancreas and Peritoneal Cavity Pathology Flashcards
Pancreatic agenesis
absence of the pancreas
not compatible w/ life
Pancreas divisum
failure of fusion of DORSAL and VENTRAL pancreatic ducts
assoc w/ chronic pancreatitis
annular pancreas
band like RING of normal pancreatic tissue that completely encircles the second portion of the DUODENUM
ectopic pancrease
pancreatic tissue can be found in the stomach, duodenum, jejunum, Meckel’s diverticulum, and ilium
What is the mechanism of acute pancreatitis?
AUTODIGESTION of pancreatic tissue by inappropriately released ACTIVATED pancreatic enzymes
What are gross and microscopic findings seen w/ acute pancreatitis?
- acute edematous pancreatitis (mild)
2. hemorrhagic necrotizing pancreatitis (severe)
What is acute edematous pancreatitis?
mild
interstitial edema, focal fat necrosis and mild acute inflammation
What is hemorrhagic necrotizing pancreatitis?
NECROSIS of PANCREATIC PARENCHYMA often with hemorrhage.
Fat necrosis can be found extrapancreatic, omentum and mesentery.
How can acute pancreatitis lead to hypocalcemia?
Ca can precipitate in areas of fat necrosis leading to hypocalcemia.
What does fat necrosis look like?
soft chalky white areas on the pancreas
Dark areas of hemorrhage and a focal area of pale fat necrosis in the peripancreatic fat is seen with…
acute hemorrhagic pancreatitis
focal pancreatic parenchymal necrosis is observed histologically with…
acute hemorrhagic pancreatitis
What is seen with long standing chronic pancreatitis?
inflammation of the pancreas
irreversible destruction of exocrine parenchyma
fibrosis
continued acinar injury
Fibrosis and atrophy that leaves residual islets and ducts with chronic inflammatory cells and acinar tissue is characteristic of what….
chronic pancreatitis
What gross and microscopic findings are associated with chronic pancreatitis?
decreased number and size of acini
Dilation of ducts
remodeling of ECM, fibrosis
What causes pancreatic insufficiency?
Repeated injury leads to the loss of acinar cell mass and fibrosis
What is pancreatic insufficiency?
def in exocrine pancreatic enzymes > can’t properly digest food
What gross and microscopic findings are associated w/ type I autoimmune pancreatitis?
Gross: White fibrotic mass
Histology: periductal lymphoplasmacytic inflammation
How is autoimmune pancreatitis treated?
surgical resection
glucocorticoid therapy
What is type I autoimmune pancreatitis?
lymphocytic sclerosing pancreatitis w/ increased IgG4 that may cause a mass formation that mimics pancreatic cancer.
What is an IgG4 related disease?
Fibroinflammatory condition
Characterized by tumefactive lesions, lymphoplasmatic infiltrate rich IgG4 positive plasma cells, fibrosis, obliterative phlebitis and elevated serum IgG4.
What are two examples of an IgG4 related disease?
Type I autoimmune pancreatitis
Kuttner’s tumor (chronic sclerosing sialadenitis)
What is kuttner’s tumor?
Chronic inflammatory infiltrate of mature lymphocytes and plasma cells w/ lymphoid follicles.
Parenchymal atorphy and fibrosis.
What are the two MC causes of pancreatic pseudocyst?
Acute pancreatitis
Trauma
What is a pancreatic pseudocyst?
localized collection of pancreatic fluid secretions w/ inflammatory fibrous cyst wall w/out epithelial lining
What does a pancreatic pseudocyst look like microscopically?
Lack of epithelial lining and instead has FIBRIN and GRANULATION.
Older adult presenting w/ abdominal pain
Serous microcystic cystadenoma
*resection is curatie
How does a Serous microcystic cystadenoma appear pathologically?
benign cyst of glycogen rich cuboidal cells surrounding small cyst containing clear thin straw colored fluid.
25% of pancreatic cysts.
Middle aged woman presents w/ a painless slow growing mass
Mucinous cystadenoma
How do you treat Mucinous cystadenoma?
surgical resection
histology to determine invasive malignant component
How does mucinous cystadenoma appear pathologically?
benign (cystadenoma) or malignant (cystadenocarcinoma).
Large multiloculated cysts filled with mucin in the tail or body (do not communicate with ducts)
Ovarian type stroma seen histologically.
What type of neoplasm is seen in both men nad women and is usually located in the head of hte pancreas?
Intraductal papillary mucinous neoplasm
What are the pathological features of an Intraductal papillary mucinous neoplasm?
Benign or malignant
Communicates w/ pancreatic duct but LACKS ovarian type stroma
Precursor to pancreatic adeno carcinoma
How does Intraductal papillary mucinous neoplasmappear grossly?
duct system is dilated
Where does pancreatic cancer rank in the list of caues of cancer death?
Pancreatic exocrine carcinoma is hte 4th leading cause of cancer death
*most is ductal adenocarcinioma
What is the MC type of pancreatic carcinoma
Ductal adenocarcinoma
What is a ductal adenocarcinoma?
Arises from dysplastic non-invasive precursor lesions in the small dcuts
Pancreatic epithelial neoplasia
What are RFs for ductal adenocarcinoma?
Cigarette smoking, obesity, physical inactivity, diabetes, chronic pancreatitis family hx, inherited predispositions and pancreatitis.
An obese pt 63 y/o F presents w/ abdominal epigastric pain, obstructive jaundice, weight loss and weakness. She recently was diagnosed w/ migratory thrombophlebitis (clot leading to vein swelling).
Ductal adenocarcinoma
What is pancreatic carcinoma frequently unresectable?
Resection is the only cure, but only 15-20% of pts are candidates for surgery.
Often, tumors are SILENT until they invade adjacent structures (peripancreatic nodes and liver), at which point it is too late to do surgery for cure
How is pancreatic carcinoma diagnosed? Is there a screen test for this?
Imaging demonstrates MASS lesion followed by biopsy.
No good screening test for the general population.
What is a whipple procedure?
The gallbladder and pancreatic head (tumor location) are removed and part of the stomach and duodenum that is near the tumor. Everything else is sewed back together.
What type of pts may develop pancreatoblastoma?
children in the first decade
What type of pts develop solid pseudopapillary tumors?
young women w/ abdominal pain and a palpable mass
How do pancreatic neuroendocrine tumors appear grossly?
Mostly well differentiated, small and well circumscribed. Most common in body or tail can also be peripancreatic.
Describe hte clinical course of pancreatic neuroendocrine tumor. How does it compare to a pancreatic exocrine carcinoma?
Typically in adults.
Metastases usually to peripancreatic nodes and liver.
Pts may have prolonged clinical course, in contrast to pancreatic exocrine carcinoma.
What hormones do Pancreatic neuroendocrine tumors produce?
- hyperinsulinism> INSULIN> hypoglycemia
2. ZE syndrome> increased GASTRIN secretion> peptic ulcers
Alpha cell tumor
glucagon> diabetes, rash, anemia
delta cell tumor
somatostatin>
diabetes, steatorrhea, hypochlorhydria
What is peritonitis?
Inflammation of thin mesothelial covered layer of tissue that lines hte abdominal cavity and most organs
What are the common causes of peritonitis?
- Bacterial peritonitis> secondary to perforation viscus
- bile peritonitis> leakage of bile causing chemical irritation
- acute hemorrhagic necrotizing pancreatitis
- foreign material
- endometeriosis> localized hemorhage
Ascites
accumulation of excess fluid in the peritoneal cavity
What is the MC of ascites?
Portal HTN associated w/ cirrhosis
What are common causes of ascites?
cancer, heart failure, tuberculosis, dialysis, pancreatic disease
What is hte most significant complication of ascites?
spontaneous bacterial eritonitis= bacterial infection that develops in the absence of a known source
*exudate of neutrophilic inflammation and fibrin present in serousal and peritoneal surfaces
What type of lab tests can be used to evaluate ascitic fluid?
- cell count
- culture and gram stain
- albumin
- total protein
- fluid cytology
cell count with differential white count:
neutrophilic count above 250/ml possible infection
Culture and gram stain
gram stain positive in 10% of spontaneous peritonitis
Albumin
serum ascites-albumin gradient, helpful to determine cause
Fluid cytology
malignancy
Which two metastatic tumors are the MC cause of maliganant ascites?
Ovarian
Pancreatic carcinomas
What is idiopathic retroperitoneal fibrosis?
Dense fibrosing process can lead to renal failure due to ureteral obstruction.
