Pancreas, Gallbladder, and Biliary Tract Pathology Flashcards
What is Pancreatic Agenesis?
Defined as absence of the pancreas. Oftentimes associated with other malformations that are incompatible with life.
What is Pancreas divisum?
Results from failure of fusion of the fetal dorsal and ventral pancreatic ducts. As a result, the bulk of the pancreas drains through the dorsal pancreatic duct and the small caliber minor papilla.
What is the most common congenital anomaly of the pancreas? How many people does it effect?
Pancreas divisum, 7% of individuals.
What is Pancreas divisum associated with?
It is almost always asymptomatic, but in some cases can be associated with chronic pancreatitis, perhaps secondary to relative stenosis caused by the bulk of secretions passing through the minor papilla.
What is Annular Pancreas?
Defined as a band-like ring of normal pancreatic tissue that completely encircles the second portion of the duodenum. Often associated with congenital anomalies. May cause duodenal obstruction.
What is Ectopic Pancreas?
Ectopic pancreatic tissue can be found in the stomach, duodenum, jejunum, Merkel’s diverticulum, and ileum. These tissue nests are usually small (millimeters in size), are often located in the submucosa, and are typically incidental findings.
What causes Acute Pancreatitis in most cases?
Stones or Alcohol.
-Anatomic changes of acute pancreatitis are secondary to autosdigestion of the pancreatic tissue by inappropriately released, activated pancreatic enzymes.
What is Chronic Pancreatitis?
Inflammation of the pancreas with irreversible destruction of the exocrine parenchyma, fibrosis and in the late stages, destruction of the endocrine parenchyma.
What leads to Pancreatic Insufficiency in Chronic Pancreatitis?
Repeated acinar cell injury leads to production of fibrogenic cytokines (TGF-beta and PDGF) that result in myofibroblast proliferation, collagen secretion, and remodeling (fibrosis) of the extracellular matrix. Pancreatic insufficiency occurs due to irreversible loss of acinar tissue.
What are the morphologic alterations in acute pancreatitis?
- Microvascular leakage causing edema
- Necrosis of fat by lipolytic enzymes
- Acute inflammation
- Proteolytic destruction of pancreatic parenchyma
- Destruction of blood vessels and subsequent interstitial hemorrhage.
What causes hypocalcemia in acute pancreatitis?
Fat necrosis (can be found in extra pancreatic fat - omentum, small bowel mesentery). Calcium can precipitate in areas of fat necrosis, resulting in hypocalcemia.
What is Type I autoimmune pancreatitis characterized by?
Lymphocytic sclerosing pancreatitis with increased IgG4 producing plasma cells. This form of pancreatitis may form a mass and mimic pancreatic cancer.
What is used to treat Type I autoimmune pancreatitis?
Steroid therapy. This type of pancreatitis is now considered to be a manifestation of IgG4-related disease.
What is IgG4-Related Disease?
Newly recognized fibroinflammatory condition characterized by tumefactive lesions, dense lymphoplasmacytic infiltrate rich in IgG4-positive plasma cells, storeroom fibrosis, obliterative phlebitis, and in some cases, elevated serum IgG4.
What is the cause of IgG4-Related Disease?
Underlying cause is thought to be some type(s) of immune mediated mechanism. Possibilities include autoimmunity as well as antibodies directed against bacterial components, which behave as autoantibodies by means of molecule mimicry in genetically predisposed individuals. As IgG4 antibodies perform anti-inflammatory functions, and because disease-specific IgG4 autoantibodies have not yet been identified in IgG4-related disease, the IgG4 antibodies may simply be a response to an inflammatory stimulus.
What are IgG4-related diseases responsive to?
Glucocorticoids
What disease is IgG4-related disease like?
Sarcoidosis, because its histopathological features are similar from site to site.
What are two most common causes of pancreatic pseudocyst?
-Acute pancreatitis
-Trauma
75 percent of cysts in the pancreas.
What are Pancreatic Pseudocysts?
Localized collection of pancreatic fluid secretions, with an inflammatory fibrous cyst wall that lacks an epithelial lining. Cyst fluid analysis often shows high amylase levels.
-Cyst lacks true epithelial lining and instead is lined by fibrin and granulation tissue.
What is Serous (microcystic) cystadenoma?
- Rare, benign cystic neoplasm composed of glycogen-rich cuboidal cell surrounding small (1-3 mm) cysts containing clare, thin, straw-colored fluid.
- Accounts for 25% of pancreatic cystic neoplasms
- Typical in older adults
- Abdominal pain
- Surgical resection is curative
What is Mucinous Cystic Neoplasm?
- Benign (mucinous cystadenoma) or Malignant with tissue invasion (mutinous cystadenocarcinoma)
- Form large multi-lobulated cysts filled with mucin
- Tumors arise in tail or body of the pancreas, do not communicate with the pancreatic duct
- Present as painless, slow-growing mass
- Treatment is surgical resection (often distal pancretectomy) and careful histologic assessment to determine if an invasive, malignant component is present.
What is IPMN (Intraductal Papillary Mutinous Neoplasm)?
Defined as a papillary mucinous neoplasm arising in the pancreatic ducts.
- Can affect men and women
- Usually older adults
- Involve head of pancreas, more often than tail
- Multifocal in 10-20% of cases
- Communicates with pancreatic duct system and lacks “ovarian type” stoma
- Can be benign or malignant if tissue invasion is present
What can happen with benign IPMN?
Benign IPMNs can demonstrate varying degrees of dysplasia (pre-malignant cytologic changes). Thus benign IPMNs can be a precursor to pancreatic adenocarcinoma.
What does IPMN look like grossly?
Grossly, the duct system is dilated, reminiscent of bronchiectasis. In some cases, the papillary tumor can be seen within the ducts. Ducts look dilated.
Where does pancreatic cancer rank in the list of causes of cancer deaths?
Fourth leading cause of cancer deaths in the U.S.
What is the most common type of pancreatic carcinoma?
Pancreatic exocrine carcinoma - almost all are DUCTAL ADENOCARCINOMAS
What are risk factors for the development of pancreatic carcinoma?
- Cigarette smoking
- Obesity
- Physical inactivity
- Diabetes
- Chronic pancreatitis
- Family history (5-10% have first degree relative with pan. carcinoma)
- Specific inherited predispositions
- Hereditary pancreatitis
What age group and location is pancreatic carcinoma most common?
- 80 percent occur over age of 60
- Most common location is head of pancreas (60percent), body (15percent), tail (5percent).
- 20 percent of tumors exhibit diffuse pancreatic involvement
What is the typical Pancreatic carcinoma presentation?
Weight loss with painless jaundice in older adult.
What are some common clinical presentations for Pancreatic carcinoma?
- Pain (abdominal, epigastric, back)
- Obstructive jaundice (tumor in head of pancreas compresses bile duct)
- Weight loss (Cachexia)
- Weakness (advanced disease
What can a small number of patients present with in Pancreatic carcinoma?
- Migratory thrombophlebitis (due to platelet-aggregating factors and procoagulants released by the adenocarcinoma)
- Pancreatic carcinomas typically remain silent until they invade into adjacent structures
Where does Pancreatic Carcinoma commonly metastasize?
Peripancreatic lymph nodes and liver.
How is Pancreatic carcinoma diagnosed?
- Imaging study that demonstrates mass lesion
- Followed by tissue biopsy, often using endoscopic ultrasound guided (EUS) biopsy technique
- Tumor is staged using T, N, M criteria
What is the Whipple Procedure for treatment of pancreatic cancer in Dr. Nelsen’s words?
Need to take out head of pancreas, distal duodenum, connect stomach to jejunum, jejunum to pancreas, hepatic duct to jejunum. Not a trivial operation.
