Tuesday, May 31, 2016

Pancreatitis and Pancreatic Cancer

Pancreatitis and Pancreatic Cancer
I can’t even stress to you how frequently PA students are tested over pancreatitis (acute and chronic) and pancreatic cancer. It seems to be one of those vague presentations that test writers take advantage of by placing in distractors (answers that seem right, but are in fact incorrect). This is meant to be a short, but hopefully helpful review of each of them, so that you are better prepared to tackle questions on these topics regardless of if they’re your in house exams during didactic, rotation exams, the PACKRAT, the PANCE, or the PANRE. I hope this helps you regardless of which avenue you find it useful. Good luck and make sure to check out TrueLearn’s free sample questions below! I’ll say, I loved their gastroenterology section the most. The vignettes were on point and difficulty wise - they were spot on with the rotation exams and PANCE-style questions.


Acute and Chronic Pancreatitis


Acute Pancreatitis
Inflammation of pancreas from prematurely activated enzymes → pancreatic autodigestion

Causes: ETOH (40%), gallstones (40%), post-ERCP, viral infection, drugs, scorpion bites, pancreatic cancer, hypertriglyceridemia, hypercalcemia, uremia
Blunt trauma (MCC in children)
Mild (most common)
- Abdominal pain, epigastric, radiates to back (50%), steady, dull, and severe
-Worse when supine and after meals
-Nausea, vomiting, anorexia

Signs
- Low grade fever, tachycardia, hypotension, leukocytosis
-Epigastric tenderness, abdominal distention
-Decreased/absent bowel sounds
-Hemorrhagic pancreatitis: Grey Turner’s sign (flank), Cullen’s Sign (periumbilical), Fox’s sign (inguinal ligament)
1. Serum amylase (MC) - nonspecific, absence does not r/o, 5xULN, normal 48-72 hours after
2. Serum lipase - more specific (3xULN)
3. LFTs - possible gallstone pancreatitis
4. Hyperglycemia, hypoxemia, leukocytosis
5. Ranson’s criteria: glucose, calcium, hematocrit, BUN, ABG, LDH, AST, WBC
6. KUB - r/o perforation
7. Abdominal U/S - identifies cause
8. CT scan (confirmatory) - most accurate
9. ERCP - severe with obstruction
1. Mild - Bowel rest (NPO), IVF, replete electrolytes, pain control (Fentanyl, Meperidine)
2. Severe - high mortality; ICU admit
-Enteral nutrition in first 72 h through NJ tube

Recurrence high in ETOH related

Complications:
- Pancreatic necrosis
- Pancreatic pseudocyst
Chronic Pancreatitis
Persistent, continued inflammation of pancreas → fibrosis and alteration of ducts = irreversible

Causes: chronic ETOH-ism
Other: hereditary, tropical, idiopathic
Severe epigastric pain, recurrent or persistent
-Nausea and vomiting
--Aggravated by drinking or eating
-Radiates to back
-Weight loss due to malabsorption, ETOH, diabetes
-Steatorrhea due to malabsorption
1. CT scan (first) - calcifications, normal does not r/o
2. KUB - pancreatic calcifications (95% specific)
3. ERCP (gold standard): “chain of lakes”
4. Serum amylase and lipase not elevated, other labs not helpful
5. Stool elastase - most sensitive and specific for pancreatic insufficiency (steatorrhea secondary to malabsorption)
1. Pain meds, NPO, pancreatic enzymes and H2 blockers, insulin, ETOH abstinence
2. Frequent, small volume, low fat meals
3. Surgery - pancreatico-
jejunostomy or pancreatic resection (Whipple’s)

Complications
-Narcotic addiction (most common)
-DM - loss of islets of Langerhans
-Malabsorption: late manifestation
-Pseudocyst
-CBD obstruction
-B12 malabsorption
-Effusions
-Pancreatic carcinoma
  • Pancreatic enzymes - inhibit CCK release, decreasing pancreatic secretions after meals
  • H2 blockers - inhibit gastric acid secretion, preventing degradation of enzyme supplements by gastric acid


Pancreatic Pseudocyst
Pancreatic Pseudocyst
Patients with chronic pancreatitis from alcohol usage or gallstones are at risk

10% occur after acute pancreatitis

Collection of fluid surrounded by granulation tissue

If it communicates with the pancreatic ductal system, it can contain digestive enzymes; does not contain epithelial lining (not cystic lesion of the pancreas)
1. Persistent abdominal pain, anorexia, or abdominal mass after pancreatitis
2. Jaundice or sepsis from infection (rare)

Physical exam
1. Tender abdomen
2. Palpable abdominal mass
3. Peritoneal signs suggesting rupture
4. Fever
5. Scleral icterus
6. Pleural effusion (common)
1. CT scan (standard)
2. ERCP - not for diagnosis, but useful for drainage


Labs
1. Serum amylase and lipase: elevated, limited use
2. Serum bilirubin and LFTs: elevated, limited use
3. Cyst fluid analysis: CEA, CEA-125, fluid viscosity, amylase (all low)
1. Supportive care only - MOST
2. Drainage for - complications, symptoms, possible malignancy
a. Percutaneous catheter drainage (preferred)
B. ERCP
C. Surgical Drainage (standard)

10% become infected, but can also rupture causing peritonitis or death

Poor prognostic factors: size of cyst and duration of presence

Outpatient monitoring: if stents placed, monitor with serial CT scans to observe resolution


Pancreatic Cancer
Pancreatic
Cancer
Most common in elderly patients (>60), African Americans

Anatomic location: pancreatic head (75%), body (20%), tail (5-10%)

RF: smoking, high fat diets, age >45, male gender, chronic pancreatitis, diabetes, heavy alcohol use, exposure to chemicals, first degree relative

Most adenocarcinomas (50%) involving head of pancreas
-Abdominal pain: vague and dull ache, epigastric, may radiate to back
-Painless Jaundice: most common with carcinoma of the head
-Weight loss; anorexia
-Recent onset glucose intolerance, but diabetes is mild
-Depression, weakness, fatigue
--Trousseau's sign: Migratory thrombophlebitis (10%)
-Courvoisier's sign: painless palpable gall in 30%
1. CT scan (preferred): pancreatic mass, dilated pancreatic and hepatic metastases, vascular involvement  
2. ERCP - most sensitive (confirms diagnosis); obtain sample for biopsy
3. MRCP - noninvasive, visualize hepatic and biliary symptoms, no tissue sampling

Tumor markers
1. CA 19-9 (more sens/spec)
2. CEA
1. Surgical resection with pancreatico-
duodenectomy  (Whipple’s procedure)
2. Chemotherapy: 5-FU and Gemcitabine
3. If unresectable - ERCP or PTC with stent placement
4. Most treatment is palliative care because of metastases



Prognosis: 5-year survival rate is 10%


1. A 45-year-old man is evaluated for a one-year history of severe chronic abdominal pain. The pain is located in the epigastric and left upper quadrant regions. Certain foods appear to precipitate the pain; however, it is unaffected by antacids. Associated symptoms include repeated bouts of loose steatorrhea and a 10 pound weight loss over the last 6 months. Three years ago he was hospitalized for acute abdominal pain. He smokes one pack of cigarettes per day and consumes 6-10 beers daily. His family history is significant for diabetes in his mother. On physical examination, he appears well. He does not have any scleral icterus.


Which of the following is most likely to confirm the diagnosis?
  1. CA 19-9
  2. D-xylose absorption test
  3. HIDA scan
  4. Serum amylase and lipase
  5. Stool elastase


Explanation:
An alcoholic patient presenting with chronic abdominal pain and diarrhea is a classic case description of chronic pancreatitis. Chronic inflammation of the pancreas, most commonly secondary to alcohol or gallstones, is characterized by abdominal pain and symptoms of pancreatic insufficiency. Pancreatic insufficiency typically manifests first as exocrine dysfunction (i.e., fat malabsorption) with gradual progression to endocrine dysfunction (i.e., diabetes) if the insult continues. The diagnosis of chronic pancreatitis can be somewhat difficult to make. Stool elastase can be beneficial in diagnosing malabsorption secondary to pancreatic exocrine insufficiency. This test is the most sensitive and specific test for pancreatic insufficiency.


Answer A: CA 19-9 is a biomarker for pancreatic cancer. The most common presenting symptom of pancreatic cancer is painless jaundice. In contrast, this patient presented with severe chronic pain. While weight loss is associated with malignancy, the history of diarrhea does not fit a diagnosis of cancer as well as one of chronic pancreatitis.


Answer B: Although a D-xylose absorption test would demonstrate that the patient above is suffering from malabsorption, unlike stool elastase, it is not specific to the pancreas.


Answer C: HIDA scans are useful for evaluating the function of the gallbladder.


Answer D: Serum amylase and lipase may be modestly elevated but are more commonly normal due to the presence of significant fibrosis and only patchy inflammation in chronic pancreatitis.


Upper GI endoscopy would not be helpful here. This would be more useful in the diagnosis of upper GI diseases, such as peptic ulcer disease.


Bottom Line: Stool elastase can be used to diagnose chronic pancreatitis.




2. A 40-year-old man presents for a routine check-up. Physical exam is within normal limits. Labs show a triglyceride level of 1500-mg/dL, total cholesterol of 140-mg/dL and LDL of 100-mg/dL. His blood pressure is 140/90 and he smokes one-half-a-pack per day. He is at risk for pancreatitis due to his:
  1. Hypertension
  2. Smoking
  3. LDL cholesterol level
  4. Triglyceride level
  5. Total cholesterol level


Explanation:
This patient has elevated triglycerides while the rest of the lipid profile is within normal limits. A high triglyceride level is a risk factor for pancreatitis. His blood pressure is on the border while his triglycerides are very elevated. Below is the typical appearance of acute pancreatitis on a CT scan. Answers A, C, & E: Hypertension and high cholesterol are risk factors for stroke. His LDL is within normal limits, thus his risk for coronary artery disease is low.


Answers A & C & E: Hypertension and high cholesterol are risk factors for stroke.  His LDL is within normal limits, thus his risk for coronary artery disease is low.


Answer B: This patient has only one risk factor for coronary artery disease, namely smoking.


Bottom Line: A high triglyceride level is a risk factor for pancreatitis. While this patient has high blood pressure, blood pressure should be measured on three separate occasions before diagnosing hypertension.




3. A 30-year-old man presents with severe abdominal pain, nausea and vomiting for the last few hours. He was eating pizza and drinking beers with a few friends when the pain began. The pain radiates from his epigastrium directly to his back and is constant. He has never had pain like this before, and he states that he has no known medical problems. He drinks a few beers and smokes a few cigarettes with his friends during the weekend but denies using either consistently. His family history is significant for a father that died of a myocardial infarction at 45, and a grandfather with coronary artery disease. On examination, his temperature is 38°C (100.4°F), pulse is 115 beats/minute, respirations are 20 breaths/minute, and blood pressure is 105/65 mm Hg. There is severe pain on epigastric palpation and there are several xanthomas under his eyes. His laboratory values are shown below.


  1. Leukocyte count 18,000 cells/mm3
  2. Lipase 175 U/L
  3. AST 70 U/L
  4. ALT 55 U/L
  5. Alkaline phosphatase 80 U/L   


Which of the following is the most likely cause of his symptoms?
  1. Alcohol
  2. Cigarette smoking
  3. Factitious disorder
  4. Gallstones
  5. Hypertriglyceridemia


Explanation:
Although the most common causes of acute pancreatitis are gallstones and alcohol, this patient has a more rare cause - hypertriglyceridemia. His family history of a grandfather with coronary artery disease and a father with a early death from a myocardial infarction suggest he may have a form of familial hypertriglyceridemia. His xanthomas also suggest hypertriglyceridemia. This should be treated immediately to decrease his morbidity and help improve his pancreatitis. In the meantime, this patient requires abdominal imaging to view the pancreas and should receive fluids and bowel rest.


Answer A: Alcohol is a common cause of pancreatitis, but it is more often a result of chronic alcoholism not the social drinking this patient describes.


Answer B: Recent studies have documented a link between cigarette smoking and acute pancreatitis, but it occurs as a result of long-term, consistent usage, not the social smoking described by this patient.


Answer C: In factitious disorder, the patient fakes or causes a condition for primary gain of being taken care of in the sick role. This patient has pancreatitis, which he is not causing on his own.


Answer D: Gallstones are an extremely common cause of pancreatitis. Although this patient should certainly receive a right upper quadrant ultrasound to search for any stones, his chronic hypertriglyceridemia is a more likely cause. Gallstones usually present with right upper quadrant pain preceding the episode of pancreatitis, and the risk factors for gallstones are usually obesity, female sex, fertility, and age over 40.


Bottom Line: Hypertriglyceridemia is a known cause of pancreatitis.

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