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Path Laboratory Case Studies Inflammation. CASE 1:. HISTORY:
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CASE 1: HISTORY: • A 19 year old woman presented to the emergency room with severe left lower quadrant abdominal pain. Physical examination revealed extreme tenderness in the left lower quadrant. Her WBC count showed a leukocytosis (19,200) with a "left shift" (75% segs and 10% bands). She was taken to surgery and a laparotomy revealed that the left fallopian tube and ovary were adherent and dilated and filled with yellow purulent material that was spilling into the peritoneal cavity from a site of rupture. Culture of this material grew Neisseria gonorrheae. (Slides 1.1 through 1.3 are the microscopic appearance of the tube, and Slide 1.4 is the gross).
PMNs Fibrin
Questions • Grossly the tube and ovary are adherent. What is demonstrated on sectioning? • 2. A microscopic cross section shows fallopian tube with a thickened wall and dilated lumen. What is the predominant inflammatory cell type seen in the wall and filling the lumen of the tube? • 3. What has happened to the vascular structures (blood vessels, lymphatics) in the tube? • 4. What is the process that is leading to the appearance of pink, homogenous material separating tissue structures and layered on the serosa? • 5. What is the diagnosis?
Answers • Grossly the tube and ovary are adherent. What is demonstrated on sectioning? The lumen is dilated and filled with purlent exudate. • A microscopic cross section shows fallopian tube with a thickened wall and dilated lumen. What is the predominant inflammatory cell type seen in the wall and filling the lumen of the tube? These cells are neutrophils (PMN's, polys). They are forming a purulent exudate. The localized collection of pus is an abscess. • What has happened to the vascular structures (blood vessels, lymphatics) in the tube? They are dilated. The blood vessels are congested (filled with blood). Lymphatics are not normally seen unless there is inflammation or obstruction. • What is the process that is leading to the appearance of pink, homogenous material separating tissue structures and layered on the serosa? The inflammation has led to exudation. The pink material is fibrin. Thus, there is a fibrinous exudate. • What is the diagnosis? Acute salpingitis with tubo-ovarian abscess. N. gonorrheae can lead to chronic inflammation of the tube with scarring, upon which an acute process can be superimposed.
CASE 2: 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 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. (Slide 2.1 is the peripheral blood smear; Slide 2.2 is the gross appearance of the appendix, and Slides 2.3 through 2.5 are the microscopic appearance).
Questions: 1. Sections of the appendix show what predominant inflammatory cell type in the wall? 2. Through what series of steps are these inflammatory cells undergoing to reach the wall? 3. In some places the wall shows disruption of the tissue. What is this process? 4. How does the CBC relate to the findings in the appendix?
ANSWERS: ACUTE APPENDICITIS • 1. Sections of the appendix show what predominant inflammatory cell type in the wall? • 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? • Chemotactic factors (such as C5a and leukotriene) are drawing in the neutrophils. They are undergoing margination in blood vessels and emigration into the tissues. • In some places the wall shows disruption of the tissue. What is this process? • 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? • Leukocytosis and a left shift are typical of many acute inflammatory processes.
@ CASE 3: HISTORY: • Following left anterior descending coronary artery thrombosis with an acute myocardial infarction involving most of the free wall of the left ventricle, a 73 year old man experienced partial paralysis of his right side. He also developed acute renal failure and hematuria. He died a short time later. (Slide 3.1 is the gross appearance of the cardiac lesion; Slides 3.2 is the gross appearance of the renal lesion, and Slides 3.3 and 3.4 demonstrate the lesion's microscopic findings).
Necrosis Hemorrhage
Normal (alive) Necrotic
Normal Dead
Questions 1. Describe the lesion in the heart at autopsy. 2. Diagnose and describe the lesion in the kidney removed at autopsy. What would be the typical gross appearance? 3. How did the renal lesion result from the myocardial infarction? 4. What was the probable cause of his paralysis?
Answers: Acute myocardial infarction, acute renal infarction • Describe the lesion in the heart at autopsy. An area of coagulative necrosis is present in the anterior left ventricular free wall and septum. • Diagnose and describe the lesion in the kidney removed at autopsy. What would be the typical gross appearance? The section of kidney shows a triangular-shaped zone, with its base at the capsular surface and its apex pointed at the medulla, that has loss of cellular detail: the nuclei are gone (karyolysis) and the cytoplasm shows enhanced red staining (eosinophilia). Note that the ghosts of tubules and glomeruli are preserved. Some sections actually show the cause, a thrombus in an artery near the apex of the area of necrosis. This necrosis is the result of ischemia, leading to an infarction (coagulative necrosis). It is very recent, so that little inflammatory infiltrate is present. • How did the renal lesion result from the myocardial infarction? A mural thrombus developed on the endocardium over the area of myocardial infarction. A portion of this thrombus broke off and was sent out into the systemic circulation, eventually going out the renal artery and lodging in a small branch to occlude the blood supply and cause an infarct. • What was the probable cause of his paralysis? A thrombus probably travelled to a cerebral artery, leading to brain infarction (a "stroke").
@ CASE 4: HISTORY: • An 83 year old woman experienced cough, fever, and shaking chills for two days prior to admission. Physical examination revealed rales in the right lung base. She was coughing up a small amount of yellowish sputum. Chest x-ray initially showed a right lower lobe infiltrate, but several days later showed infiltrates throughout the right lung. Sputum culture grew Streptococcus pneumoniae. (Slide 4.1 demonstrates the gross appearance of the lung, and Slides 4.2 through 4.4 illustrate the microscopic findings).
Normal lung with air space Air sacs filled with pus
(Bacterial) Neutrophils
Questions 1. How would you describe the gross appearance of the lung? 2. What do you see in the alveolar spaces in the lung? 3. How would this differ from a causative agent such as influenza virus? 4. What chemical mediators are responsible for fever? 5. What is the diagnosis?
Answers: Acute pneumonia • How would you describe the gross appearance of the lung? Patchy areas of yellowish tan consolidation are present, consistent with bacterial pneumonia. • What do you see in the alveolar spaces in the lung? The alveolar spaces are filled with an exudate containing numerous neutrophils along with some macrophages and pink strands of fibrin. Alveolar capillaries are congested and filled with RBC's. • How would this differ from a causative agent such as influenza virus? Inflammation caused by viruses is typically interstitial and mostly composed of mononuclear cells. However, the damage done by viral inflammation in the lung can predispose to bacterial infection. • What chemical mediators are responsible for fever? Interleukin-1 (IL-1) and tumor necrosis factor (TNF). • What is the diagnosis? This is an acute pneumonia. Streptococcus pneumoniae typically produces a lobar pattern of involvement. A more virulent organism (usually seen in hospitalized patients) is Staphylococcus aureus which can cause abscess formation.
CASE 5: HISTORY: • A 35 year old male had a history of intravenous drug use. Over several days' time, he developed a high fever, then dyspnea. On physical examination, his temperature was 103o F, and a heart murmur was heard. Needle tracks and a red, tender, fluctuant area were noted near the left antecubital fossa. A blood culture grew Staphylococcus aureus. Despite antibiotic therapy, he died three days later. The aortic valve is shown in Slide 5.1. Sectioning of the myocardium revealed multiple small soft yellow foci (Slide 5.2). The epicardium showed a shaggy appearance (Slide 5.3).
Questions 1. What is the appearance of the aortic valve (Slide 5.1)? 2. Note the dark purple focus in this section of myocardium. Describe what you see in these foci (Slide 5.2). 3. How do these foci in the myocardium relate to the lesions on the aortic valve? 4. Bacteria are being phagocytozed because what agents are acting as opsonins? 5. What is the diagnosis? What is the pathogenesis of this process? 6. What is the process involving the epicardium (Slide 5.3)?
Answers: Acute bacterial endocarditis • What is the appearance of the aortic valve? At autopsy, the aortic valve showed extensive necrosis with vegetations composed of yellowish-red, friable material. • Note the dark purple foci in this section of myocardium just by viewing the slide without the microscope. Under the microscope, describe what you see in these foci. These foci are small abscesses filled with neutrophils. The myocardium and adjacent epicardial fat show suppurative necrosis. • How do these foci in the myocardium relate to the lesions on the aortic valve? The vegetations on the aortic valve break off and embolize. Some may go out the coronary arteries to myocardium. These are "septic" emboli because they contain bacteria. • Bacteria are being phagocytozed because what agents are acting as opsonins? Immunoglobulin (IgG) and complement C3b. • What is the diagnosis? What is the pathogenesis of this process? This is acute bacterial endocarditis with septic emboli and myocardial and epicardial abscesses. Most IV drug users do not use sterile needles, so are at risk for infection (his antecubital lesion was probably an abscess at the site of injection). • What is the process involving the epicardium (Slide 5.3)? The inflammation has led to exudation of fibrin, which has organized into a fibrinous pericarditis. The pink strands of fibrin gave the grossly shaggy appearance.
CASE 6: • HISTORY: • A 53 year old man was the driver of a car involved in a head-on collision with another vehicle at 45 mph. He was not wearing a seat belt and his 1969 Chevy did not have an airbag. He sustained blunt trauma to the upper abdomen. On admission to hospital, he complained of severe abdominal and mid-back pain. He appeared gravely ill. A peritoneal lavage revealed bloody abdominal fluid. Serum lipase was 7500 U/L. At surgery, multiple liver lacerations were noted, and there were flecks of white, chalky material in adipose tissue adjacent to a slightly swollen pancreas.
Infiltrating FAT replacing normal tissue *Enzymes are digesting pancreatic tissue*
Questions 1. Diagnose and describe what you see grossly (Slide 6.1) and microscopically (Slide 6.2). 2. How does this lesion occur? 3. Name another site at which trauma can produce this lesion.
Answers: Fat necrosis of pancreas 1. Diagnose and describe what you see grossly and microscopically. This is fat necrosis. Scattered tan areas are seen throughout the pancreas. There is not much of a neutrophilic exudate, but the adipose tissue shows areas of necrosis that are smudgy, amorphous, and pink to violaceous (compare with normal adipose tissue). • How does this lesion occur? The blunt force traumatic injury (probably from the steering wheel) damaged the pancreas so that pancreatic enzymes (lipases) were released and began to digest surrounding tissues. Thus, fatty acids released from triglycerides combined with calcium to produce the white, chalky, soap-like material typical of fat necrosis. • Name another site at which trauma can produce this lesion. Trauma to the breast may produce fat necrosis.
@ CASE 7: HISTORY: • A 42 year old woman underwent hysterectomy because of pelvic pain and irregular menstrual cycles associated with heavy menstrual bleeding. She also complained of an intermittent, whitish mucoid vaginal discharge between period for several months.
Questions 1. What is the gross appearance of the cervix (Slide 7.1)? 2. Microscopically, the uterine cervix at the squamocolumnar junction has ectocervix lined by glycogen rich, non-keratinizing stratified squamous epithelium. The endocervical canal is lined by a layer of columnar mucinous epithelial cells. At the squamocolumnar junction, the mucinous epithelium exhibits focal squamous metaplasia. What do you see adjacent to this area in the fibromuscular stroma (Slides 7.2 and 7.3)? 3. Why is there metaplasia (Slide 7.4)? 4. What is the diagnosis?
Answers: Chronic cervicitis • What is the gross appearance of the cervix? The epithelium is red (hyperemic) with dilated blood vessels. • What do you see adjacent to this area in the fibromuscular stroma? There is a moderate chronic inflammatory cell infiltrate. This infiltrate consists of lymphocytes, plasma cells, macrophages, and a few neutrophils. • Why is there metaplasia? The columnar epithelium has undergone squamous metaplasia in response to the chronic irritation. This process is reversible. • What is the diagnosis? Chronic cervicitis. This inflammation led to the discharge noted by the patient. Etiologic agents could include: yeast (Candida), trichomonas, Gardnerella, chlamydia, or N. gonorrheae.
CASE 8: HISTORY: • A 45 year old man had a 30 year history of alcohol abuse. He died from head trauma in a motor vehicle accident. At autopsy, the liver showed a diffusely nodular, firm surface. (Slide 8.1 demonstrates a normal liver in situ for comparison; Slide 8.2 shows the gross appearance of the liver in this case, and Slides 8.3 and 8.4 show the microscopic findings).
