Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + TEST TAKING TIP Download Section PDF Listen +++ ++ Test Taking Tip Neuroendocrine tumors of the pancreas are a favorite. Know the clinical presentation, diagnosis, and medical and surgical treatment particularly in conjunction with multiple endocrine neoplasia (MEN) syndromes. + ANATOMY/PHYSIOLOGY Download Section PDF Listen +++ +++ What is the duct of Wirsung? ++ Major pancreatic duct that forms in the pancreatic head and descends inferiorly and joins the intrapancreatic portion of the common bile duct to form the common pancreaticobiliary channel proximal to the ampulla of Vater. +++ What is the duct of Santorini? ++ Accessory pancreatic duct that drains the anterior portion of the pancreatic head ++ FIGURE 16-1. Arterial supply to the pancreas. Multiple arcades in the head and body of the pancreas provide a rich blood supply. The head of the pancreas cannot be resected without devascularizing the duodenum unless a rim of pancreas containing the pancreaticoduodenal arcade is preserved. (Reproduced from Brunicardi FC, Andersen DK, Billiar TR, et al. Schwartz's Principles of Surgery. 9th ed. http://www.accessmedicine.com. Copyright © The McGraw-Hill Companies, Inc. All rights reserved.) Graphic Jump LocationView Full Size||Download Slide (.ppt) +++ What is the blood supply to the head of the pancreas? ++ Anterior and posterosuperior pancreaticoduodenal arteries from the gastroduodenal artery that form collaterals with branches of the superior mesenteric artery (SMA) (inferoanterior and posterior pancreaticoduodenal arteries) +++ What is the venous drainage? ++ It parallels the arterial supply; drains into the portal system via the superior mesenteric and splenic veins. +++ Which enzyme is responsible for pancreatic necrosis in presence of bile? ++ Phospholipase A +++ What defines a high-output pancreatic fistula? ++ Output in excess of 200 mL/d +++ BENIGN PANCREATIC DISEASES +++ What are the etiologies of acute pancreatitis? ++ Gallstones and alcohol account for >90% of cases. Other causes include hyperlipidemia, hypercalcemia, trauma, pancreatic duct obstruction, ischemia, drugs, familial, and idiopathic. +++ What are some common medications implicated as possible etiologies of pancreatitis? ++ Azathioprine, furosemide, thiazides, sulfonamide, tetracycline, steroids, estrogens, ethacrynic acid, and H2 blockers +++ What metabolic conditions could cause pancreatitis? ++ Hyperlipidemia (types I, IV, and V have been implicated); hypercalcemia, which is most commonly found with hyperparathyroidism that could lead to intraductal precipitation of calcium +++ How is acute pancreatitis diagnosed? ++ The diagnosis of pancreatitis requires 2 of the following 3 features: abdominal pain characteristic of acute pancreatitis, a serum amylase or lipase level at least 3 times the upper limit of normal, and characteristic findings of acute pancreatitis on computed tomography (CT). +++ Which enzyme is implicated in etiology of pancreatitis? ++ Trypsin +++ Which serum enzyme rises within 2 hours of the onset of pancreatitis and peaks within 48 hours? ++ Amylase +++ What antibiotics are indicated for patients with mild pancreatitis? ++ None! Antibiotics neither improve the course nor prevent septic complications. +++ What CT scan findings are suggestive of chronic pancreatitis? ++ Dilated pancreatic duct, calcifications, and parenchymal atrophy +++ What are the early Ranson criteria (on admission)? ++ Glucose >200 mg/dL, Age >55, LDH >350 IU/L, AST >250 IU/L, WBC >16k +++ What are the late Ranson criteria (48 hours)? ++ Calcium <8.0 mg/dL, HCT drop >10%, PaO2 <60 mm Hg, BUN increase by 5 or more mg/dL, base deficit >4 mEq/L, fluid sequestration >6 L +++ How do Ranson criteria predict mortality? ++ 0 to 2 signs, 2% 3 to 4 signs, 15% 5 to 6 signs, 40% 7 to 8 signs, ~100% +++ What are the indications for surgery in chronic pancreatitis? ++ Intractable abdominal pain, common bile duct obstruction, duodenal obstruction, persistent pseudocysts, pancreatic fistula or ascites, variceal hemorrhage secondary to splenic vein obstruction (treated by splenectomy), to rule out pancreatic malignancy, colonic obstruction +++ What are possible complications of pancreatitis? ++ Pancreatic necrosis, pseudocyst, pancreatic fistulas, hemorrhage, pancreatic ascites, abscess/sepsis +++ How does chronic pancreatitis present? ++ Abdominal pain, diabetes, steatorrhea, and pancreatic calcification. Amylase is not typically elevated in chronic pancreatitis +++ Initial management of pancreatic duct stricture from chronic pancreatitis: ++ Pancreatic duct stenting +++ What are some surgical procedures used in chronic pancreatitis? ++ Duval procedure (distal pancreatectomy with end-to-end pancreaticojejunostomy) Puestow procedure (lateral side-to-side pancreaticojejunostomy), which is most widely used and preferred; pancreatic resection, pancreatic denervation, islet cell transplantation (for type I diabetes mellitus) Frey procedure (coring out of diseased portion of pancreatic head and then lateral pancreaticojejunostomy for chronic pancreatitis) Beger procedure (duodenum-preserving pancreatic head resection) +++ When is a follow-up CT scan for pancreatitis indicated? ++ Clinical deterioration (pseudocyst, abscess, or necrosis) +++ Why does shock occur in severe pancreatitis? ++ Hypotension and subsequent shock are related to hemodynamic changes resembling sepsis rather than hypovolemia. Cardiac output is generally increased with decreased peripheral vascular resistance +++ What percentage of pseudocysts spontaneously resolve within 4 to 6 weeks? ++ 50% +++ How are pseudocysts managed? ++ Expectant, supportive management for 4 to 6 weeks If no resolution occurs, wait until a thick, fibrous wall has formed and perform internal cyst drainage via a cystgastrostomy, cystjejunostomy, or cystduodenostomy. A biopsy should always be performed to rule out malignancy External drainage may be pursued for infected pseudocysts or ones with immature walls +++ How long does it take a pseudocyst to mature? ++ 4 to 6 weeks +++ Indication for surgical intervention for pancreatic pseudocysts: ++ Pseudocyst has not resolved by 6 weeks and also persistently greater than 6 cm +++ List the enteric methods of pseudocyst drainage: ++ Cystogastrostomy, cystoduodenostomy, and Roux-en-y cystojejunostomy, lateral pancreaticojejunostomy +++ Most common cause of pancreatic abscess: ++ Infection of pseudocyst +++ What is the usual time frame for development of pancreatic abscesses associated with acute pancreatitis? ++ 2 to 4 weeks +++ What CT scan criteria are used for diagnosis of pancreatic necrosis? ++ Well-demarcated areas of nonenhancing pancreatic tissue >3 cm or occupying more than 30% of the gland +++ How is infected pancreatic necrosis diagnosed? ++ CT-guided percutaneous fine-needle aspiration +++ What antibiotics are indicated in pancreatic necrosis involving >30% of the gland? ++ Imipenem or meropenem +++ Aspiration of the necrotic pancreas is negative, now what? ++ Continue nonoperative management +++ How are pancreatic fistulas managed? ++ NPO, parenteral nutrition. Somatostatin has been showed to accelerate closure rate. If no resolution, an endoscopic retrograde cholangiopancreatography (ERCP) to evaluate anatomy and ultimate surgical internal drainage or distal resection. +++ How does hemorrhage manifest in the setting of pancreatitis? ++ It usually is due to erosion of an arterial pseudoaneurysm secondary to pseudocyst, abscess, or necrotizing pancreatitis. Diagnosis is by angiography. Immediate surgery is indicated should the patient become unstable. Selective embolization may be possible in stable patients. +++ Which congential anomaly results from failure of fusion of the dorsal and ventral pancreatic ducts? ++ Pancreas divisum +++ BENIGN PANCREATIC TUMORS +++ What is the most common benign neoplasm in the pancreas? ++ Serous cystadenoma. These tumors have a low rate of malignant transformation. +++ What is the treatment for serous cystadenoma? ++ Resection generally recommended but this lesion can be closely followed in high-operative-risk patients. +++ What tumor exhibits sunburst central calcification on CT scan? ++ Serous cystadenoma +++ MALIGNANT PANCREATIC TUMORS +++ Overall 5-year survival rate for pancreatic cancer: ++ <5% in general. Recent reports have cited a 5-year survival of 20% to 25%. +++ Median survival time of pancreatic cancer patients: ++ 4 to 6 months +++ What is the most significant modifiable risk factor for pancreatic cancer? ++ Cigarette smoking +++ What are the presenting signs of pancreatic cancer? ++ Abdominal pain, jaundice (could be painless jaundice but this is actually more commonly associated with ampullary and duodenal neoplasms), and weight loss +++ What imaging studies are needed for diagnosis? ++ Ultrasound to evaluate biliary anatomy, CT scan +++ What are some inherited disorders that increase the risk of pancreatic cancer? ++ MEN, hereditary pancreatitis, familial adenomatous polyposis, hereditary nonpolyposis colorectal cancer, Von Hippel-Lindau, Gardner syndrome +++ What serologic tumor markers are measured? ++ CA 19-9 (sensitivity 83%, specificity 82%), CEA (sensitivity 56%, specificity 75%) +++ What imaging modality is beneficial in assessing the T stage of the tumor in pancreatic cancer? ++ Endoscopic ultrasonography +++ Which chemotherapeutic agents are commonly used in adjuvant therapy? ++ The 2 most active agents are 5-fluorouracil and gemcitabine. Mitomycin C, streptozocin, doxorubicin, and lomustine have also been used. 5-FU potentiates radiation therapy. +++ FDA approved for combination with gemcitabine for first-line treatment of locally advanced, unresectable, or metastatic pancreatic cancer: ++ Erlotinib (Tarceva) +++ What percentage of patients with pancreatic cancer will have had a new diagnosis of diabetes? ++ 20% +++ T1 pancreatic cancer: ++ Tumor limited to the pancreas, <2 cm +++ T2 pancreatic cancer: ++ Tumor limited to the pancreas, >2 cm +++ T3 pancreatic cancer: ++ Tumor extends beyond the pancreas but without involvement of the celiac axis or the SMA +++ T4 pancreatic cancer: ++ Tumor involves the celiac axis or the SMA ++ FIGURE 16-2. The pancreaticoduodenectomy (Whipple procedure) can be performed either with the standard technique, which includes distal gastrectomy (A) or with preservation of the pylorus (B). The pylorus-sparing version of the procedure is used most commonly. (Reproduced from Gaw JU, Andersen DK. Pancreatic surgery. In: Wu GY, Aziz K, Whalen GF, eds. An Internist's Illustrated Guide to Gastrointestinal Surgery. Totowa, NJ: Humana Press; 2003:229. With kind permission of Springer Science+Business Media.) Graphic Jump LocationView Full Size||Download Slide (.ppt) +++ What T stage denotes unresectable disease? ++ T4, by definition +++ What reconstruction is performed during after standard pancreaticoduodenectomy (Whipple procedure)? ++ End-to-side pancreaticojejunostomy, hepaticojejunostomy, gastrojejunostomy +++ What percentage of pancreatic neoplasms are mucinous cystic neoplasms? ++ 2% +++ What distinguishes mucinous cystic neoplasm from intraductal papillary mucinous neoplasm? ++ Mucinous cystic neoplasm rarely communicates with the main pancreatic duct. +++ Should mucinous cystic neoplasm be resected? ++ Yes, because of malignant potential. +++ What rash is seen with glucagonoma? ++ Necrolytic migratory erythema +++ From which islet cells do glucagonoma arise? ++ α-cells +++ What laboratory test confirms the diagnosis of glucagonoma? ++ Elevated plasma glucagon >150 pg/mL (many will have levels in excess of 500 pg/mL) +++ Which test is used for localization of glucagonoma? ++ CT or MRI +++ What is another name for VIPoma? ++ Verner Morrison syndrome +++ What triad is associated with VIPoma? ++ Watery diarrhea, hypokalemia, and achlorhydria +++ What tests are used for localization of VIPoma? ++ Ultrasound, CT (often tumor is 3 cm or larger), angiography, and transhepatic venous sampling may be used as second-line in difficult cases +++ What is the appropriate treatment of VIPoma? ++ Enucleation or surgical resection, depending on location +++ Where are 85% of all gastrinomas located? ++ In the gastrinoma triangle, the borders are the pancreatic neck/body junction, confluence of cystic and common hepatic ducts and the junction of second/third portions of duodenum +++ What percentage of islet cell tumors do insulinomas comprise? ++ 25% +++ How can this condition be distinguished from factitious hyperinsulinemia? ++ C-peptide: insulin ratio is 1:1 in insulinoma +++ What percentage of insulinomas are malignant? ++ 10% +++ What triad is suggestive of the diagnosis of insulinoma? ++ Whipple: symptoms of hypoglycemia with fasting, blood glucose <50 mg/dL, relief with glucose intake +++ What test is diagnostic for insulinoma? ++ 72-hour fast. Insulin and glucose are measured every 6 hours. Symptoms of hypoglycemia develop in 12 hours. Insulin: glucose ratio >0.3 or serum insulin >6 μU/mL is diagnostic. +++ What is the surgical procedure of choice for insulinoma? ++ Enucleation +++ What are the 4Ds of glucagonoma ++ Diabetes, dermatitis, deep venous thrombosis, depression +++ What percentage of patients with glucagonoma have diabetes? ++ >75% +++ What does VIP in VIPoma stand for? ++ Vasoactive intestinal peptide +++ The diagnosis of VIPoma is supported by what serum VIP level: ++ >200 pg/mL +++ Management of the diarrhea of VIPoma: ++ Octreotide +++ What is the rarest pancreatic islet cell tumor? ++ Somatostatinoma +++ What somatostatin level confirms the diagnosis of somatostatinoma? ++ >10 ng/mL +++ What study should be used to define the extent of pancreatic islet cell tumors? ++ Octreotide scan +++ What is the most malignant pancreatic endocrine tumor? ++ Gastrinoma +++ What is the most benign pancreatic endocrine tumor? ++ Insulinoma +++ What is the surgical management of endocrine tumors in tail of the pancreas? ++ Distal pancreatectomy +++ What is the surgical management of endocrine tumors in head of the pancreas? ++ Whipple procedure +++ This receptor is found on many pancreatic islet cell tumors: ++ Somatostatin receptor