Hepatocellular carcinoma: This is an example of a HCC nodule with secondary cirrhosis
The tumor tissue is:
1. Moderately differentiated, still showing some evidense of cords and sinusoids, and
2. well demarcated by fibrotic tissue
What disease is this? What are the arrows? What distinguishes the normal tissue from the pathological tissue?
Hepatocellular adenoma: AKA hepatic adenomas, these are uncommon benign epithelial liver tumors
1. Hepatocellular adenoma: 90% arise in women 20-40 yrs and are associated with oral contraceptive use; they are mostly focal, well defined lesions. In this picture, note that the remaining liver is a pale, yellow brown because of fatty changes due to chronic alcoholism
2. Normal liver tissue with well organized hepatocytes, sinusoids, and portal tract
3. The hepatocellular adenoma at right, composed of cells resembling hepatocytes, but notice the tissue is disorganized with poorly formed hepatocyte cords and sinusoids and does not contain a normal lobular architecture
What is this? What epithelial type is the lining? What is special about the lining?
Gallbladder: Mucosa is simple columnar epithelial lining specialized for water absorption to concentrate bile
Note that the epithelium has no crypts or goblet cells
Greek name for gallbladder is cholecyst from chole (bile) and cyst (bladder)
What is this? What is the arrow?
Top panel: Normal gallbladder
Bottom panel: >80% of all gallblader and bile duct cancers are carcinomas (tumors arising from epithelium). Most carcinomas produce small, glandular like structures (arrow), they are specfically classifed as adenocarcinomas.
Gallstones (cholelithiasis) is present is >80% of gallbladders containing carcinoma; risk of developing carcinoma is increased if stones are large and symptomatic
What is this?
Normal pancreas, showing
1. Secretory acini
2. Endocrine pancreas islets of Langerhans
3. Exocrine pancreas acinar units
What is this, specifically?
Exocrine pancreatic acinar unit
1. Nucleus of centroacinar cell
2. boundary of acinar unit
3. secretory vesicles
4. acinar cell nucleus
5. acinar lumen
6. leading to larger pancreatic duct
What is this? What are the arrows? What are the two cells in the bottom panel?
Islets of Langerhans: contain alpha cells (secrete glucagon), beta cells (secrete insuline), and delta cells (secrete somatostatin)
Top arrow: Normal pancreatic islet surrounded by
Bottom arrow: normal exocrine pancreatic acinar tissue
Bottom panel: immunoperoxidase staining used to ID cell types in the islets
At left: antibodies specific for glucagon ID alpha cell
At right: antibodies to insulin ID beta cell
What disease is this? What is the asterisk? What causes the patient's problems? What is the most common association with this disease?
Chronic pancreatitis: Thought to result from recurrent episodes of acute pancreatitis, leading to progressive destruction of acinar and islet cells, followed by healing and replacement of normal pancreatic tissue with fibrosis (asterisk).
In this healing process, macrophages remove necrotic tissue.
This is followed by proliferation of capillaries and fibroblasts and deposition of collagen.
In advanced disease, large areas are replaced by fibrosis, causing exocrine and endocrine tissues to become atrophic and permanently lose functoin.
Chronic pancreatitis is most commonly associated with alcoholism, and less so with biliary tract disease, hypercalcemia, or hyperlipidemia
What disease is this? What characterizes it? How does necrosis occur? What are the arrows?
Chronic pancreatitis, characterized by: Inflammation and extensive necrosis of pancreas parenchyma, focal enzyme necrosis of pancreatic fat, and blood vessel necrosis that leads to hemorrhage
Necrosis occurs primarily by intra-pancreatic activation of digestive enzymes, which also leads to formation of intraductal protein plugs that eventually calcify and form stones
Top arrow: inflammatory infiltrate rich in neutrophils
Bottom arrow: Hemorrhage resulting from enzymatic digestion of vascular walls
What is this? What disease does it commonly lead to? What is the significance of the top arrow? What are the other arrows?
Insulinitis: inflammation of an Islet of Langerhans
Often leads to Type 1 diabetes mellitus
Top arrow: presence of lymphocytic infiltrates suggests autoimmune mechanism; eventual destructin of islet leads to absolute lack of insulin (characteristic of type 1 diabetes)
Middle arrow: extensive amyloi deposition in islet
Bottom arrow: hyalinzation of islet
The changes seen in the bottom two arrows are common in islet of patients with Type 2 diabetes mellitus
What is this? What are the arrows? What is the bottom panel?
Islet cell adenoma
Top arrow: Islet cell adenoma, separated from the pancreas
Middle arround: Thin collagenous capsule surrounds the adenoma
Bottom arrow: Normal islets are seen for comparison
Bottom panel: higher magnification of the islet cell adenoma showing normal pancreas with islets at right and collagenous capusle separating two compartments
Beta cells within islets may over produce insulin and lead to severe hypoglycemia; G cells may also be present and lead to multiple gastric and duodenal ulcerations from over production of gastrin (Zollinger-Ellison syndrome)