Pancreas

Question 1

Embryology of pancreas

Answer 1

Develops from endoderm of duodenum. Two pouches develop (ventral and dorsal) that then rotate and fuse by 8th week.

Question 2

Annular pancreas

Answer 2

Ventral pancreas malrotates and encircles 2nd portion of duodenum -> pancreatitis, bowel obstruction, peptic ulcer. Tx: duodenoduodenostomy (bypass)

Question 3

Pancreas divusm

Answer 3

Failure to fuse two duct systems, such that duct of Santorini (normally accessory duct) becomes the main duct. Majority are asymptomatic, but if it results in inadequate drainage -> chronic pain, recurrent pancreatitis

Question 4

Exocrine function of pancreas

Answer 4

Acinar cells secrete enzymes. Centroacinar and ductal cells secrete water and electrolytes. Overall 1-5 L/day of isosmotic, pH 8 fluid.

Question 5

Cephalic phase of digestion

Answer 5

Stimuli of sight/smell of food -> vagal activation -> gastric acid production -> duodenal acidification -> secretin release -> pancreatic HCO3 release

Question 6

Gastric phase of digestion

Answer 6

Antral distention and protein -> gastrin -> gastric acid production -> duodenal acidification -> secretin release -> pancreatic HCO3 release

Question 7

Intestinal phase

Answer 7

Duodenal acid and bile stimulate secretin, duodenal fat/protein release CCK -> release of pancreatic enzymes

Question 8

Endocrine function of pancreas

Answer 8

Insulin (beta cells), glucagon (alpha cells), somatostatin (delta cells), pancreatic polypeptide

Question 9

Clinical uses of somatostatin

Answer 9

1. Tx sx of neuroendocrine tumors (e.g. carcinoid, VIPoma, gastrinoma) 2. Convert high-output fistulae to low-output fistulae

Question 10

Drugs that can cause pancreatitis

Answer 10

Isoniazid, estrogens, azathioprine (Imuran), HCTZ, sulfonamides, pentamidine (antifungal for PCP), didanosine (HAART), chemo for ALL, Depakote

Question 11

What is a sentinel loop on XRay?

Answer 11

Distention and/or air-fluid levels near a site of abdominal distention. Can be seen in pancreatitis due to secondary ileus

Question 12

Ranson’s criteria

Answer 12

see attached

Question 13

Causes of chronic pancreatitis other than alcohol

Answer 13

HyperPTH, CF, congenital pancreatic anomalies, hemochromatosis. NOT commonly gallstones though

Question 14

Pancreatic pseudocyst definition

Answer 14

Fluid collection without epithelial lining

Question 15

Pancreatic pseudocyst treatment

Answer 15

1/3 resolve on own with TPN and NPO. After 4 weeks (wall has matured) can do internal drainage: RenY cyst-jejunostomy or cyst-gastrostomy

Question 16

Pancreatic adenocarcinoma epi

Answer 16

Arises from exocrine pancreas. M > F, older, blacks > whites, smoking risk factor, most occur in the head, association with MEN1.

Question 17

Trousseau’s syndrome

Answer 17

Migratory thrombophlebitis assoc with GI adenocarcinoma, esp pancreatic

Question 18

Tumor markers for pancreatic adenocarcinoma

Answer 18

Ca 19-9, alk phos

Question 19

Whipple procedure

Answer 19

Removal of gallbladder, CBD, antrum of stomach, duodenum, proximal jejunum and head of pancreas

Question 20

Palliative procedures for pancreatic cancer

Answer 20

Relieve biliary and/or duodenal obstruction. Pain control with chemical splanchicectomy (sympathetic nerves to pancreas)

Question 21

Pancreatic cystadenocarcinoma

Answer 21

Females age 40-60 yrs, more commonly in the body/tail. Malignant potential, but better prognosis than adencarcinoma. Tx: resection.

Question 22

Pancreatic cystadenoma

Answer 22

Older/middle aged women, presents with vague abdominal sx. Two types: serous = benign, mucinous = malignant potential. Tx: resection

Question 23

Insulinoma

Answer 23

Majority are benign, solitary lesions. Diagnosis: fasting serum insulin > 25. To distinguish from exogenous insulin, check C-peptide. Tx: surgical resection

Question 24

Gastrinoma

Answer 24

Causes ZES. Majority malignant/multiple. About 20% assoc with MEN1. Dx: serum gastrin > 1000. Tx: resection difficult bc often multiple; PPI.

Question 25

VIPoma

Answer 25

Causes achlorhydria and watery, secretory diarrhea -> hypokalemia. Most are malignant. Tx: surgery, chemo; octreotide (somatostatin analogue).

Question 26

Why does VIPoma cause watery diarrhea?

Answer 26

VIP is a potent stimulator of gut cyclic adenosine monophosphate (cAMP) production, which leads to massive secretion of water and electrolytes (mainly potassium).

Question 27

Why does VIPoma cause achlorhydria?

Answer 27

In the stomach, VIP inhibits histamine- and pentagastrin-stimulated acid secretion.

Question 28

Glucagonoma

Answer 28

Rare; most are malignant, large primary tumors that metastasize. Causes 4Ds – DM (hyperglycemia), dermatitis (necrolytic migratory erythema), deep vein thrombosis (DVT) and depression. Dx: glucagon > 1000

Question 29

Somatostatinoma

Answer 29

Very rare, large tumor that metastasizes. Gallstones, diarrhea, hypochlorhydria, weight loss, abdominal cramps. Dx: somatostatin > 1000