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GI Path Lab 4

Slide 99 [WebScope] [ImageScope]

Liver: Extensive Collapse
(Massive Hepatic Necrosis)

Most of this liver is devoid of hepatocytes. The parenchyma consists of funny-shaped ducts, blood vessels, including both arteries and veins, collagen fibers, debris-filled phagocytes, and inflammatory cells, mainly lymphocytes. There are several patches of residual but disorganized liver cells with cholestasis, as in Slide 94. This is an example of a liver that has been subjected to a nightmarish injury, which resulted in loss of most of the liver cells. How long and how successfully the patient lives depends upon on how much viable liver tissue remains. In this case, the patient received a liver transplant because of biochemical failure.

  1. What are the two most common causes of this type of massive necrosis?

  2. When liver cells are lost in a large area of parenchyma such as this, what happens to that parenchyma? How can you tell that is happening?

  3. Suppose this patient had lived for several months. What is likely to happen in the areas of confluent necrosis?

  4. Why do you think the cholestasis occurred?



Slide 92 [WebScope] [ImageScope]

Chronic Alcoholic Liver Disease

This liver is a histologic mess. In a hematoxylin and eosin-stained section such as this, it is almost impossible to decipher what regions of the microscopic anatomy are involved with what process. Nevertheless, very dramatic changes are evident.

  1. Although alcohol commonly leads to a fatty liver, in this liver there is little fat, only a few scattered fat vacuoles.

    How does alcoholic injury lead to a fatty liver?

    What is the explanation for the lack of fat in this liver?

  2. In certain areas, there are large misshapen hepatocytes that contain coarse red smudges that often appear beaded. These are Mallory bodies.

    What are Mallory bodies?

    What happens to a liver cell that contains one?

  3. Inflammatory cells are present. These are mainly small lymphocytes, in and around some of the portal tracts and scattered in the sinusoids. There are scattered neutrophil-rich foci often associated with Mallory bodies in this slide. However, in typical active alcoholic hepatitis, the dominant inflammatory cells are neutrophils that accumulate where the Mallory bodies are most prominent.

    Why are the neutrophils present in typical alcoholic hepatitis?

    Why are they not more prominent in this slide?

    Why are there so many lymphocytes?

  4. Scattered about are big chunks of bilirubin in canaliculi, indicative of cholestasis. What are two mechanisms to explain cholestasis in a liver such as this?

  5. At the edges of many portal tracts, there is a proliferation of small duct-like structures, some of which appear only as cords of double layered cuboidal cells. These are ductules, and they proliferate when there is interference with bile flow, either locally or diffusely in the liver. Thus they are a marker of cholestasis. Why are they proliferating in this liver?

  6. If we were to stain the collagen in this liver, we would find that there is considerable collagen in the central zones, where the Mallory bodies are the most numerous, and collagen extends from these central zones to connect with portal tracts. Continued deposition of collagen is likely to lead to what?



Slide 95 [WebScope][ImageScope] and Slide 96 [WebScope] [imageScope]

Two Patterns of Cirrhosis, one more Regular and the other more Irregular

  1. What is the definition of cirrhosis?

  2. Do both these slides satisfy that definition?

  3. There are clear differences in the patterns of disease in these two slides. Actually, it is not even necessary to use the microscope to recognize these differences. Simply placing the slides against a sheet of white paper will show these differences quite well.

  4. Which of these livers is likely to fail first from a biochemical standpoint?

  5. Which of these two is likely to lead to portal hypertension?

  6. What is the importance of giving these two slides different descriptive names?

  7. Which one is likely to be caused by alcoholic injury?

  8. In Slide 95, there are all stages of nodule formation beginning with irregular clusters of hepatocytes. Note that as the nodules appear to enlarge, the stroma between them (the septate scars) becomes compressed. What results from this compression?



Slide 13 [WebScope] [imageScope]

Hemochromatosis

The pigment in this slide is hemosiderin. Note that it is present in liver cells, in bile ducts, and in phagocytes in the collagen.

  1. Does this liver satisfy the criteria for cirrhosis?

  2. What are the best tests to prove that a patient has hemochromatosis?



Slide 97 [WebScope] [ImageScope]

Esophageal Varices: A Complication of Cirrhosis

Note the location of the huge veins in the wall of the esophagus.

  1. Why are they so big?

  2. Is this patient necessarily cirrhotic?

  3. What is the major complication of these varices, and why does it happen?



Slide 98 [WebScope] [ImageScope]

Hepatoma (hepatocellular carcinoma): Also usually a complication of cirrhosis

On one side of the slide, nodules of hepatocytes separated by interconnecting scars characterize the liver. On the opposite side is a neoplasm in which the cells caricature normal hepatocytes, but the degrees of differentiation vary from one area to another.

  1. What cellular characteristics indicate that it is neoplastic?

  2. In this country, what is the most common liver disease in which a hepatoma is likely to arise?

  3. What is the pigment in the non-neoplastic hepatocytes? Does it give a clue as to the underlying liver disease?



Slide 199 [WebScope] [ImageScope]

Metastatic Colorectal Carcinoma in Liver

In this slide of liver, there are several separate masses of carcinoma.

  1. What type of carcinoma is this? How do you know?

  2. What is the differential diagnosis for this type of carcinoma when it occurs in the liver?



The answers to the path lab questions will be posted approximately 48-72 hours after the lab sessions. These are abbreviated answers, not a full discussion of the topics. You can find them in the M2 CTools site resources. In the folder for each sequence the will be a folder called 'Path Lab Resources'


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