Module 2: GI: Pancreatic Lesions Flashcards
Moving onto the Pancreatic lesions, first lets start with the inflammatory lesions. What is the etiology for acute pancreatitis?
Gallstones and alcohol are the most common causes
What is the pathogenesis for acute pancreatitis?
Pancreatic Injury — release of tyrpsin then amylase and lipase — released FAs combine with Ca2+ —- saponification (chalky white deposits on surface of pancreas )
- –can lead to hypocalcemia and tetany
- -Liquefactive necrosis of the exocrine pancreas
What is the presentation for acute pancreatitis?
Excruciating and sudden onset epigastric pain
Fever
Nause
Vomiting
Explain the elevation in the enzymes with acute pancreatitis?
Amylase elevated initially
—first 24 hours is more sensitive
Lipase elevated 72-96 hours
–more specific
What is the definitive diagnosis of acute pancreatitis?
CT/MRI
- -fat in the peripancreatic space and liquefactive in the exocrine pancreas also called pancreatic acini necrosis
- -spares the islets of langerhans
what is the most important prognostic factor for acute pancreatitis?
Decreased calcium levels
–lower the worse the prognosis
What are complications of acute pancreatitis?
Septic Shock (recurrent bacterial infections)
Hypovolemic Shock
Acute tubular necrosis
Hypocalcemia
–cardiac arrhythmias and tetany
ARDS
–enzymes damage lung (diffuse alveolar damage due to damage to the type II pneumocytes)
DIC
–Enzymes activate both clotting pathways
In acute pancreatitis is the endocrine or exocrine pancreas destroyed?
Exocrine pancreas destroyed first
- -islets spread
- -liquefactive necrosis
- -fat necrosis
Next moving onto chronic pancreatitis, what is the etiology?
Chronic alcoholism most common cause
–recurrent acute pancreatitis
Cystic Fibrosis (due to mucus plugs)
Malabsorption: intraluminal hydrolysis of
-fat, fat soluble vitamins, and B12 is defective
In chronic pancreatitis is the endocrine or exocrine pancreas destroyed?
Starts in exocrine and affects islets
then progresses to endocrine
What investigations are done for chronic pancreatitis?
CT scan most accurate
–dystrophic calcification and fibrosis of the pancreas
What is the most important prognostic indicator for chronic pancreatitis?
Dystrophic Calcification with low Calcium
–causes malabsorption of Vit D
What are complications of chronic pancreatitis?
- Malabsorption
- DM type I (insulin for life)
- Pancreatic Adenocarcinoma
- Pancreatic pseudocysts (lined by fibrous scar/granulation tissue, due to atrophy of the epithelium) (susceptible to infection) (seen on histology)
Moving on to Autoimmune pancreatitis (lymphoplasmacytic sclerosing pancreatitis/ duct-destructive pancreatitis). There are two types, describe type I
Type 1: Lymphoplasmacytic infiltrate centered around large and medium sized interlobular duct
- -periductal and perivenular fibrosis
- -obliterative phlebitis (arteries are spared)
- -Increased IgG4 plasma cells
- -male predominance
Describe type 2 autoimmune pancreatitis
Type 2: Lymphoplasmacytic Infiltrate centered around ducts
- -granulocytic epithelial lesions with partial/complete duct obstruction/obliteration
- -Ig4 plasma cells are usually absent
- -affects genders equally
What is the presentation for autoimmune pancreatitis?
Jaundice Abdominal Pain Mass-like lesion (Differentiates it from chronic pancreatitis) Recent onset of DM Weight Loss
What investigations are done for autoimmune pancreatitis/
Increased pancreatic enzymes and hypergammaglobulinemia (IgG4)
Autoantibodies: ANA, anti-lactoferrin (ALF), anti-carbonic anhydrase II (ACA-II) and Rheumatoid Factor (Rh)
Moving on to carcinoma of the pancreas, what is the most common location?
Head/Neck of the pancreas
What are the predisposing factors for carcinoma of the pancreas?
Smoking (number one)
chronic pancreatitis
KRAS mutations
p53 mutations
Is carcinoma of the pancreas exocrine or endocrine?
Exocrine is more common and more dangerous
–endocrine is less common and less dangerous
What is the presentation of pancreatic cancer?
Obstructive Jaundice (Esp if its in the head) due to compression of the ampulla vader that is initially painless Pain (lots ,esp at night) ---retroperitoneal invasion of sacral nerve plexus Abdominal Mass Intestinal Obstruction Pruritus because of bile salts Virchows Node Sister Mary Joseph Nodule
What investigations are done for pancreatic cancer?
Biopsy is most accurate
–ductal adenocarcinoma or dysplastic glands invading the pancreas
CA19-9 most accurate tumor marker
–CEA is also elevated
IHC stain of SMAD4 :allows differentiation between benign and malignant
What are the complications of pancreatic cancer?
Metastasis: --Regional lymph nodes, liver and lungs Invasion: --bowel, colon and stomach Diabetes --Damage to islets Lots of Mucin production --Trousseau's Syndrome (Recurrent migratory thrombophlebitis) in superficial veins --DVT (renal vein) NBTE --Marantic Endocarditis: sterile vegetations on valves (fibrin only)
What is the treatment and prognosis?
Whipple’s Procedure + chemo for Treatment:
–Head and neck, gallbladder (All bile is backing up and gallbladder is inflamed) and proximal duodenum removed
Terrible prognosis
What is an insulinoma?
Benign, solitary tumor that arise from B cells
–increase insulin
What are the clinical manifestations of insulinoma?
Whipple’s Triad:
- -Signs and symptoms of hypoglycemia
- -hypoglycemia relieved by intake of glucose
- -low blood glucose levels
How do patients with insulinomas present?
Confusion Blurred vision Muscle Weakness Sweating Palpitations --mostly all due to the hypoglycemia
Now finally there are three main pancreatic neoplasms to be touched on really quick. What is a acinar cell carcinoma?
Subcutaneous Fat Necrosis & Panniculitis due to lipase
–affects white more and is super rare
What is an intra-ductal papillary mucinous neoplasm (IPMN)?
Duct is dilated and filled with mucin
- -Majority in head of pancreas
- -Lacks ovarian type stroma
Finally what is a mucinous cystic neoplasm?
Tall columnar mucin secreting cells with surrounding ovarian type stroma
- -majority in tail of pancreas (not connected to the ductal system)
- -Exclusively in women
What does histological slide for chronic pancreatitis look like?
All the pink is collagen
- -exocrine is the dilated or distended ducts
- -endocrine is your islets (Which are atrophied and to the left of the pic)
Patients can develop something called pseudocysts in chronic pancreatitis, what is this?
Collection of serous fluid in the pancreas lined by fibrous scars
In regards to pancreatic cancer, explain the spreading via seeding and then metastasis.
Spreading: duodenum first, pylorus then colon
Metastasis: regional lymph nodes, liver, lung
