Inflammation Case Studies


CASE 2: Acute appendicitis


Clinical History:

Over an 18 hour period, a 24-year-old man noticed increasing abdominal pain which was first centered in the periumbilical region, but later localized in the right lower abdominal quadrant. Physical examination demonstrated involuntary guarding and rebound tenderness in the right lower quadrant. A CBC revealed a WBC count of 18,550/microliter with a left shift. He was taken to surgery and an appendectomy was performed. The appendix examined in surgical pathology was swollen and covered with a purulent exudate. (image 2.1 is the peripheral blood smear; image 2.2 is the gross appearance of the appendix, and images 2.3 through 2.5 are the microscopic appearance).
  1. Sections of the appendix show what predominant inflammatory cell type in the wall?

    2. There are numerous PMN's present, typical of acute inflammation. Also seen are marked vascular dilation with congestion and tissue edema (leading to the swollen appearance of the appendix). A fibrinopurulent exudate is present on the surface, producing the gross appearance noted in surgical pathology.

  2. Through what series of steps are these inflammatory cells undergoing to reach the wall?

    3. Chemotactic factors (such as C5a and leukotriene) are drawing in the neutrophils. The neutrophils are undergoing margination in blood vessels (mainly venules) and emigrating into the tissues.

  3. In some places the wall shows disruption of the tissue. What is this process?

    4. This is suppurative necrosis (a form of liquefactive necrosis) resulting from the action of the PMN's on the tissue.

  4. How does the CBC relate to the findings in the appendix?

    5. Leukocytosis and a left shift are typical of many acute inflammatory processes.