Question 199
A 72-year-old male suddenly loses strength and sensation in his right upper extremity. His family takes him to the hospital where he is then admitted. Despite treatment, he dies 6 days later and an autopsy is performed. The pathologist identifies a lesion in the lateral aspect of his left frontal and parietal lobes at the central sulcus. The lesion is exhibited below. Of the following, what process is occurring?
A. Coagulative necrosis
B. Liquefactive necrosis
C. Caseous necrosis
D. Gangrenous necrosis
E. Fat necrosis
Answer For Question 199
Answer: B (Liquefactive necrosis)
Explanation: In liquefactive necrosis, there is rapid break-down of the tissue after injury and the architecture is not identifiable (unlike in coagulative necrosis, in which the overall architecture of the organ is identifiable despite the death of the cells). In patients who sustain a stroke, liquefactive necrosis of the brain will quickly develop. Phagocytic cells (activated microglial cells and blood-derived macrophages (yellow arrows are examples)) will engulf the myelin and cellular debris
Question 200
A 31-year-old male with a past history of chronic alcoholism presents to the emergency room with a three-day history of abdominal pain. Despite therapeutic measures, he dies and an autopsy is performed, which reveals the finding illustrated in the image. Of the following, what was the mechanism for the pathologic change illustrated?
A. Widely disseminated metastatic tumor
B. Release of gastric contents
C. Release of pancreatic enzymes
D. Bacterial sepsis
E. Undiagnosed tuberculosis
Answer for Question 200
Answer: C ( Release of pancreatic enzymes)
Explanation: The image illustrates fat necrosis–white-yellow deposits in the greater omentum caused by lipases released from a damaged pancreas (e.g., in patients with acute pancreatitis) that cleave triglyceride esters in adipocytes. The subsequent linking of released fatty acids to calcium produces the deposits. Alcohol use is a major cause of pancreatitis as are gallstones in the duct.
Question 201
A pathology resident is completing his autopsy report and describing the microscopic appearance of lesions he identified during the exam. While viewing the section of the heart, which included a lesion he identified grossly, he found the features illustrated in the image below. Of the following, what would be the best description for the yellow star (first) and blue star areas (second) respectively?
A. Coagulative necrosis/coagulative necrosis
B. Coagulative necrosis/liquefactive necrosis
C. Dry gangrene/wet gangrene
D. Coagulative necrosis/abscess
E. Caseous necrosis/abscess
Answer for Question 201
Answer: B (Coagulative necrosis/liquefactive necrosis)
Explanation: At the yellow arrow, the nuclei are absent, but the architecture is preserved; at the blue arrow, the architecture is completely disrupted and the tissue type is not identifiable. There are no granulomas; and, at the blue arrow are only maybe a few scattered inflammatory cells and not a collection of neutrophils, as would characterize an abscess. Wet and dry gangrene are normally used in the context of the extremities and not the heart.
Question 202
A pathologist is examining histologic sections from an autopsy when he identifies the pathologic lesion illustrated below. There are numerous such lesions in the organ being examined under the microscope. Of the following, what is the most likely etiology?
A. Bacterial infection
B. Viral infection
C. Parasitic nematode infection
D. Neoplastic proliferation
E. Trauma
F. Mycobacterial infection
Answer for Question 202
Answer: F (Mycobacterial infection)
Explanation: The lesion is a granuloma, which is composed of epithelioid histiocytes (macrophages), which are macrophages with prominent cytoplasm (which is why there is alot of pink and not as much blue associated with the cell). The granuloma is outline below with the white lines. Giant cells (yellow arrow) are often found in granulomas, but are not required for the diagnosis. Of the conditions listed, granulomas are most often associated with a mycobacterial infection, such as tuberculosis. Although tuberculosis is normally associated with caseating granulomas and the granuloma below has no caseation, the history of numerous granulomas in the organ (which is the liver) is consistent with miliary tuberculosis, and non-caseating granulomas do occur in patients with tuberculosis
Question 203
A researcher in a medical school laboratory is studying the effects of introducing an infectious organism to a mouse model. Following the infection of the mouse, a short time period is allowed and then the mouse is sacrificed and the tissue studied microscopically. Assuming the mouse model mimics a human reaction (i.e., similar cellular mediators are involved), of the following, which chemokine played the largest role in producing the illustrated image?
A. C-X-C chemokine
B. C-C chemokine
C. C chemokine
D. CX3C chemokine
E. C-D-C chemokine
Answer for Question 203
Answer: B (C-C chemokine)
Explanation: The prominent cell type in the image is an eosinophil (blue arrows). Eotaxin, which is specific for eosinophils, is a C-C chemokine. C-X-C chemokines are chemoattractants for neutrophils; C chemokines for lymphocytes, and CX3C chemokines are chemoattractants for monocytes and T-cells.
Question 204
An 18-month-old child dies due to cardiorespiratory failure following a lengthy disease course dating back to near his time of birth and characterized by muscular hypotonia. An autopsy is performed and the pathologist identifies a markedly enlarged heart and a mildly enlarged liver. A microscopic section of the heart reveals the finding illustrated below. Of the following, what is the most likely enzyme deficiency causing the disease process?
A. Glucose-6-phosphatase
B. Muscle phosphorylase
C. Lysosomal glucosidase
D. Glucocerebrosidase
E. Sphingomyelinase
Answer for Question 204
Answer: C (Lysosomal glucosidase).
Explanation: The clinical scenario, autopsy findings, and image indicate Pompe disease, which is due to a deficiency of lysosomal glucosidase. Essentially the only glycogen storage disease that primary involves the heart is Pompe disease. Glucose-6-phosphatase is deficient in vonGierke disease, which primarily involves the liver and muscle phosphorylase is deficient in McArdle disease, which involves the skeletal muscles and presents in adults. Glucocerebrosidase is deficient in Gaucher disease, which primarily involves the liver and spleen in the most common form; and sphingomyelinase is deficient in Niemann-Pick disease, which primarily involves the liver and spleen, but also the CNS in the most common form.
Question 205
A 53-year-old chronic alcoholic who is homeless was brought to the emergency room by his friends because he has been coughing up blood for two days. His friends also report that he has had a chronic cough and has been losing weight. He does smoke cigarettes. Physical examination reveals him to be cachectic. Despite treatment in the hospital, he dies and an autopsy is performed, which reveals a 7.3 cm soft friable area in the upper lobe of the right lung and numerous small (few millimeter) soft white-yellow nodules in the liver and spleen. The image below depicts one of the small nodules in the spleen. Of the following, what is the most likely etiology for this change?
A. Giant cell neoplasia
B. Infection with gram positive bacilli
C. Infection with gram negative bacilli
D. Infection with acid-fast bacilli
E. Aspiration of food
F. Methanol poisoning
Answer for Question 205
Answer: D (Infection with acid-fast bacilli)
Explanation: The lesion is a caseating granuloma. The central area is caseous necrosis (yellow arrow), which appears grossly as soft yellow, white-yellow, or yellow-tan material, and can be referred to as “cheesy”. The architecture is not identifiable. Surrounding the caseous necrosis are inflammatory cells–epithelioid macrophages (blue arrows) and often multi-nucleated giant cells (red arrows). The lesions in the liver and spleen came from blood-borne spread of the bacillus from the lesion in the lung (the lesions in the spleen and liver would be called miliary TB). Tuberculosis is an acid fast bacillus and is most commonly associated with caseous necrosis. Other conditions can cause caseous necrosis, and tuberculosis infections can produce non-caseous necrosis.
