Block 9 Cellular Pathology Dr Johnson

1. •A 65-year-old man presents with crushing chest pain. Physical examination reveals that he is pale and diaphoretic. EKG and laboratory findings suggest ischemic heart disease. Which of the following would be seen in his myocardium after 15 hours without treatment?

Caseous necrosis

Coagulation necrosis

Liquefaction necrosis

Fibrinoid necrosis

Gangrene

After 15 hours without treatment, the myocardium in a 65-year-old man with ischemic heart disease would show coagulation necrosis. Coagulation necrosis occurs due to ischemia, which leads to the denaturation of proteins and loss of cell structure. This type of necrosis is characterized by the preservation of tissue architecture, with the affected area appearing pale and firm. In this case, the patient's symptoms of crushing chest pain, pallor, and diaphoresis, along with the EKG and laboratory findings, suggest that he is experiencing a myocardial infarction, which is commonly associated with coagulation necrosis.

Explanation

After 15 hours without treatment, the myocardium in a 65-year-old man with ischemic heart disease would show coagulation necrosis. Coagulation necrosis occurs due to ischemia, which leads to the denaturation of proteins and loss of cell structure. This type of necrosis is characterized by the preservation of tissue architecture, with the affected area appearing pale and firm. In this case, the patient's symptoms of crushing chest pain, pallor, and diaphoresis, along with the EKG and laboratory findings, suggest that he is experiencing a myocardial infarction, which is commonly associated with coagulation necrosis.

2. •Reactive oxygen species (ROS) are very important in inflammation and neoplasia as well as the aging process. Which of the following best describes the mechanism of action of ROS?

Increase permeability of cell membranes, but leaves them intact.

Enhance mitosis

Lipid peroxidation of cell membranes

Stabilize DNA

Enhance glycolysis

Reactive oxygen species (ROS) can cause lipid peroxidation of cell membranes. This process involves the oxidation of lipids in the cell membrane by ROS, leading to the formation of lipid peroxides. This can disrupt the integrity and function of the cell membrane, potentially causing damage and inflammation. Lipid peroxidation is implicated in various pathological conditions, including inflammation, neoplasia, and the aging process.

Explanation

Reactive oxygen species (ROS) can cause lipid peroxidation of cell membranes. This process involves the oxidation of lipids in the cell membrane by ROS, leading to the formation of lipid peroxides. This can disrupt the integrity and function of the cell membrane, potentially causing damage and inflammation. Lipid peroxidation is implicated in various pathological conditions, including inflammation, neoplasia, and the aging process.

3. •A 50-year-old woman with a history of unstable angina suffers an acute myocardial infarction. Thrombolytic therapy with tissue plasminogen activator (tPA) is administered to restore coronary blood flow early in the course of this myocardial infarction. In spite of this therapy, the degree of myocardial fiber injury may increase because of which of the following?

Increased intracellular pH

Detachment of proteins from ribosomes

Release of neutrophil proteases

Production of reactive oxygen species

Activation of caspases

Thrombolytic therapy with tissue plasminogen activator (tPA) is used to dissolve blood clots in the coronary arteries and restore blood flow to the heart. However, during an acute myocardial infarction, there is an increased production of reactive oxygen species (ROS) in the damaged heart tissue. These ROS can cause oxidative stress and damage to the myocardial fibers, leading to an increase in the degree of myocardial fiber injury. Therefore, despite the administration of tPA, the production of reactive oxygen species can further contribute to the damage caused by the myocardial infarction.

Explanation

Thrombolytic therapy with tissue plasminogen activator (tPA) is used to dissolve blood clots in the coronary arteries and restore blood flow to the heart. However, during an acute myocardial infarction, there is an increased production of reactive oxygen species (ROS) in the damaged heart tissue. These ROS can cause oxidative stress and damage to the myocardial fibers, leading to an increase in the degree of myocardial fiber injury. Therefore, despite the administration of tPA, the production of reactive oxygen species can further contribute to the damage caused by the myocardial infarction.

4. A 40-year-old homeless woman presents to a free clinic. She is incoherent, but mentions something about her feet. Her shoes and socks are removed and reveal these lesions. What is the pathogenesis of these lesions?

Coagulation necrosis plus bacterial infection

Liquefaction necrosis plus viral infection.

Caseation necrosis plus fungal infection

Fibrinoid necrosis plus autoimmune disease

The lesions on the woman's feet suggest a combination of coagulation necrosis and bacterial infection. Coagulation necrosis occurs when there is tissue death due to the interruption of blood supply, typically caused by bacterial toxins. Bacterial infection further exacerbates the tissue damage and inflammation. This explanation is supported by the woman's incoherence and her mention of her feet, indicating a possible systemic infection.

Explanation

The lesions on the woman's feet suggest a combination of coagulation necrosis and bacterial infection. Coagulation necrosis occurs when there is tissue death due to the interruption of blood supply, typically caused by bacterial toxins. Bacterial infection further exacerbates the tissue damage and inflammation. This explanation is supported by the woman's incoherence and her mention of her feet, indicating a possible systemic infection.

5. •A study is performed involving the microscopic analysis of tissues obtained from surgical procedures. In some of the heart biopsy specimens the myocardial cells were large because of an increase in the amount of cytoplasm and slightly enlarged nuclei. Which of the following conditions is most likely to have resulted in this finding?

Patient with hypertension

Patient with gastro-esophageal reflux

Patient with long standing ischemia

Breast tissue of nursing mother

The finding of large myocardial cells with increased cytoplasm and slightly enlarged nuclei is consistent with hypertrophy, which is often seen in patients with hypertension. Hypertension leads to increased workload on the heart, causing the myocardial cells to enlarge in order to meet the increased demand. This is a compensatory mechanism to maintain cardiac function. The other options, such as gastro-esophageal reflux, long standing ischemia, and breast tissue of a nursing mother, are not associated with this specific histological finding.

Explanation

The finding of large myocardial cells with increased cytoplasm and slightly enlarged nuclei is consistent with hypertrophy, which is often seen in patients with hypertension. Hypertension leads to increased workload on the heart, causing the myocardial cells to enlarge in order to meet the increased demand. This is a compensatory mechanism to maintain cardiac function. The other options, such as gastro-esophageal reflux, long standing ischemia, and breast tissue of a nursing mother, are not associated with this specific histological finding.

6. •A 45-year-old man, an ultimate fighter, is injured in a match. His left arm dislocated and became quite swollen and turned purple and then black. Which of the following will ultimately be present in this lesion?

Bilirubin

Hemosiderin

Melanin

Lipofuscin

Biliverdin

The correct answer is Hemosiderin. Hemosiderin is a pigment that is derived from the breakdown of red blood cells. In this case, the injury caused the blood vessels to rupture, leading to bleeding and the accumulation of blood in the tissues. As the blood breaks down, hemosiderin is formed and deposited in the lesion. This explains the discoloration of the swollen arm, starting with purple and eventually turning black.

Explanation

The correct answer is Hemosiderin. Hemosiderin is a pigment that is derived from the breakdown of red blood cells. In this case, the injury caused the blood vessels to rupture, leading to bleeding and the accumulation of blood in the tissues. As the blood breaks down, hemosiderin is formed and deposited in the lesion. This explains the discoloration of the swollen arm, starting with purple and eventually turning black.

7. •A 79-year-old man has a large myocardial infarction involving much of the left ventricular free wall. He develops decreased cardiac output leading to congestive heart failure (CHF). Five years later he presents with dyspnea and lethargy. An echocardiagram reveals cardiomegaly and a large area of akinesia. As a result the affected myocardium is thin and bulges beyond the surface of normal musculature. A diagnosis of ventricular aneurysm is made. Which of the following laboratory tests would best indicate poor peripheral tissue perfusion in this patient?

Elevated glucose

Elevated lactic acid

Elevated creatinine

Elevated Troponin

Elevated Glycogen

In this patient with ventricular aneurysm, the thin and bulging myocardium indicates poor cardiac function and decreased cardiac output. Poor peripheral tissue perfusion can result from this decreased cardiac output. Elevated lactic acid levels would indicate anaerobic metabolism and tissue hypoperfusion, as lactic acid is produced as a byproduct of anaerobic metabolism. Therefore, elevated lactic acid would best indicate poor peripheral tissue perfusion in this patient.

Explanation

In this patient with ventricular aneurysm, the thin and bulging myocardium indicates poor cardiac function and decreased cardiac output. Poor peripheral tissue perfusion can result from this decreased cardiac output. Elevated lactic acid levels would indicate anaerobic metabolism and tissue hypoperfusion, as lactic acid is produced as a byproduct of anaerobic metabolism. Therefore, elevated lactic acid would best indicate poor peripheral tissue perfusion in this patient.

8. This photomicrograph was taken from a lung biopsy. The patient had multifocal lesions in the lung and liver. He was 75-years-old and had moderately productive cough and a low grade fever. Special stains of this tissue are pending. Which of the following best describes the image shown?

Caseous necrosis

Coagulative necrosis

Abscess

Liquefactive necrosis

Apoptosis

The image shown in the photomicrograph is consistent with caseous necrosis. This can be inferred from the presence of multifocal lesions in the lung and liver, along with the patient's symptoms of cough and fever. Caseous necrosis is a form of necrosis characterized by a cheese-like appearance and is commonly associated with tuberculosis. The special stains of the tissue are pending, which may further confirm the diagnosis.

Explanation

The image shown in the photomicrograph is consistent with caseous necrosis. This can be inferred from the presence of multifocal lesions in the lung and liver, along with the patient's symptoms of cough and fever. Caseous necrosis is a form of necrosis characterized by a cheese-like appearance and is commonly associated with tuberculosis. The special stains of the tissue are pending, which may further confirm the diagnosis.

9. A 45-year-man complains of nausea and vague abdominal discomfort. He is slightly jaundiced. Oil Red O and PAS stains are negative. Which of the following best describes the cells noted in the center of this slide?

They are necrotic

They are apoptotic

They are filled with fat

They are filled with glycogen and protein

They are filled with sodium and water

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Explanation

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10. •A sample of liver is sent to a pathology laboratory for diagnostic purposes. It is characterized by scattered loss of individual cells, with the microscopic appearance of nuclear and cell fragmentation surrounded by membrane. The overall tissue structure remains intact. Which of the following best describes the outcome of this lesion?

Inflammation

Phagocytosis

Fibrosis

Abscess formation

Liquefactive necrosis

The outcome of the described lesion is phagocytosis. Phagocytosis is the process by which cells engulf and digest cellular debris or foreign substances. In this case, the scattered loss of individual cells with nuclear and cell fragmentation is being cleared by phagocytic cells, such as macrophages, without causing significant damage to the overall tissue structure.

Explanation

The outcome of the described lesion is phagocytosis. Phagocytosis is the process by which cells engulf and digest cellular debris or foreign substances. In this case, the scattered loss of individual cells with nuclear and cell fragmentation is being cleared by phagocytic cells, such as macrophages, without causing significant damage to the overall tissue structure.