Gall Bladder And Pancreas Pathology PDF

GALL BLADDER AND PANCREAS PATHOLOGY CHOLELITHIASIS Cholelithiasis is the presence of stones in the gall bladder The stones are usually composed of: Cholesterol stones (most common) Bilirubin salts (pigment stones) CHOLELITHIASIS CHOLECYSTITIS May be acute or chronic Both are often associate...

GALL BLADDER AND PANCREAS PATHOLOGY CHOLELITHIASIS Cholelithiasis is the presence of stones in the gall bladder The stones are usually composed of: Cholesterol stones (most common) Bilirubin salts (pigment stones) CHOLELITHIASIS CHOLECYSTITIS May be acute or chronic Both are often associated with the presence of calculi in the gall bladder In the acute types it is often caused by obstruction of the neck by the stones with bile stasis There may be superimposed bacterial infection with pus formation In the acute acalculous type the gall bladder may not show any calculi but believed to result from stasis of bile Usually occurs in patients who have been involved in major surgery, severe trauma, severe burns or sepsis. CHOLECYSTITIS In chronic cholecystitis, the wall of the gall bladder is usually thickened and may show fibrous adhesions There may be calculi formed The mucosa may be hyperplastic, normal or atrophic There is usually infiltration by lymphocytes There may also be seen outpouchings or sinuses of the mucosa called Rokitansky-Aschoff sinuses Sometimes the wall of the gall bladder may become calcified and is called a porcelain gall bladder CHRONIC CHOLCYSTITIS GALL BLADDER CARCINOMA Relatively uncommon neoplasm Usually more common in women Associated with the presence of gall bladder stones Most commonly found in the fundus May be exophytic or infiltrative Adenocarcinoma are the most common followed by squamous carcinoma Have very poor prognosis THE PANCREAS (EXOCRINE) Normal:- The pancreas secretes 2 to 2.5 liters per day of a bicarbonate-rich fluid containing digestive enzymes and proenzymes Includes trypsinogen, chymotrypsinogen, proelastase,, and phospholipase A and B. The most important conditions of the exocrine pancreas are: Cystic fibrosis, acute and chronic pancreatitis and tumours. These disorders are difficult to diagnose because of the hidden position and large reserve function of the organ. Congenital anomalies Agenesis Pancreas divisum / 2 separate parts Annular pancreas Ectopic pancreas seen in the stomach, duodenum, jejunum, meckels diverticulum and ileum. - PANCREATITIS - Inflammation of the pancreas almost always associated with acinar cell injury. - Acute pancreatitis: - Characterized by the acute onset of abdominal pain resulting from enzymatic necrosis and inflammation of the pancreas. - About 80% of cases are associated with biliary tract disease (cholestasis) and alcoholism. - Other causes include: - Infection with mumps and Coxsackie viruses - Acute ischaemia from vascular thrombosis, vasculitis and shock - Drugs eg thiazide diuretics and estrogens - Hyperlipoproteinaemia and hypercalcemic states - Obstruction of pancreatic duct by parasites eg ascaris worm - Idiopathic eg perioperative - Pathogenesis: - Acute pancreatitis results from autodigestion of the pancreas by the proteolytic enzymes via activation of trypsinogen - The activated trypsin activates other proenzymes - Clinical features: Abdominal pain (acute abdomen): elevated plasma levels of amylase and lipase; hypocalcaemia leucocytosis, hemolysis, DIC, ATN, ARDS and shock - [Sequelae include]: Sterile pancreatic abscess, a pancreatic pseudocyst and duodenal obstruction. - PATHOGENESIS OF ACUTE PANCREATITIS - ACUTE PANCREATITIS - The pancreas is swollen and edematous - There is leakage of enzymes with resulting fat necrosis which shows as areas of chalky white material - There is haemorrhage into the stroma - Infiltration of the stroma by acute inflammatory cells are seen - ACUTE PANCREATITIS - PANCREATIC PSEUDOCYSTS - Localised collections of pancreatic secretions that develop after inflammation of the pancreas - Can also follow trauma to the abdomen. - Formed by drainage of pancreatic secretions from damaged ducts into interstitial tissue and walled off by fibrous tissue. - Can also mimic malignancy clinically however they are usually unilocular (malignancy -- multi). - CHRONIC PANCREATITIS - Characterized by repeated bouts of mild to moderate pancreatic inflammation, with continued loss of pancreatic parenchyma and replacement by fibrous tissue. - Islet cells are initially spared but are later also lost - [Associated factors]: alcoholism, hypocalcaemia, hyper lipoproteinaemia, pancreatic divisum - Pathogenesis & Morphology - Pathogenesis:- - Ductal obstruction by concretions - Excessive secretion of protein - Oxidative stress induced by alcohol - Necrosis-fibrosis - Morphology: Xrised by irregularly distributed fibrosis, loss & reduced size of acinar, relative sparing of islets and obstructed ducts of all sizes. chronic inflammation. - Clinical features: - Usually seen in middle aged males particularly alcoholics - Moderately severe abdominal pain, recurrent attacks of back pain - Or initially silent until development of pancreatic insufficiency and diabetes mellitus. - There may be mild fever chronic malabsorption and duct obstruction can also develop - pancreatic pseudocyst and carcinoma are possible other sequelae. - Comparison of the sequelae of acute and chronic pancreatitis - Tumours - Most are solid, malignant, glandular tumours - [Benign Cystic tumours]: - Make up less than 50% of all and - Occur most often in elderly women - Usually located in body or tail. - Include Serous cystadenomas; Others are mucinous (with benign or borderline malignant or Malignant forms). - CARCINOMA OF THE PANCREAS - Relatively uncommon in this environment. - 60% arise in the head - 5% arise in the body - 5% arise in the tail - 20% diffusely infiltrative - Virtually all are adenocarcinomas - Some may be desmoplastic or mucinous - In the case of carcinoma of the Head of pancreas may obstruct bile flow and present early - Others present late with lymph node and liver metastasis + lungs and bones - Perineural invasion is common - Adenosquamous and giant cell variants do occur - CARCINOMA OF THE PANCREAS - Little is known of the etiology - smoking is the strongest environmental influence. - [Others are]: alcoholism, high fat diet, chronic pancreatitis, diabetics mellitus. - K-ras mutation is seen in 90% of cases & P-53 mutation in 60-80%. - Clinical Features - They tend to remain silent until late in evolution - Produce pain when they impinge on nerve fibres in the retroperitoneum. - Pain is usually the first symptom but this time the tumour is usually beyond cure. - Others are jaundice, - wt loss, anorexia, generalized malaise and weakness migratory thrombophlebitis (trousseau\`s sign). - Tumour markers -- CEA, CA19-9 -- unreliable.