Question 236
A 62-year-old male is mowing his lawn when he suddenly feels a pressure in his chest. He finishes mowing the lawn and then tells his wife, who calls an ambulance. He is admitted to the hospital from the emergency room. A troponin I obtained 3 hours after the episode of chest discomfort is elevated. Of the following, which would be most characteristic of the cell indicated by the yellow arrow?
A. Triglyceride accumulation
B. Swelling of rough endoplasmic reticulum
C. Plasma membrane blebs
D. Nuclear chromatin clumps
E. Fragmentation of nucleus
Answer for Question 236
Answer E (Fragmentation of the nucleus)
Explanation: The cells in the top left corner of the image, including the one at the arrow, are undergoing coagulative necrosis–which is irreversible cell injury. Comparing these cells to those in the bottom right corner, those in the top left hand corner are more eosinophilic and have lost their nucleus. Answers A-D are found with reversible cell injury; answer E is the only one listed that is characteristic of irreversible cell death. A-D can all be present in the irreversibly injured cells (since they can remain to some degree as the cells transition from reversible to irreversible injury), but the best choice to answer the question is fragmentation of the nucleus.
Question 237
A pathologist is performing an autopsy on a 9-month-old infant. Gross examination of the liver identifies the parenchyma to be slightly firm and vaguely nodular. Microscopic examination of the liver reveals the findings illustrated in the slide below. Of the following, what substance is accumulating in the liver?
A. Glucocerebroside
B. Sphingomyelin
C. Iron
D. Cholesterol
E. Thorotrast
Answer for Question 237
Answer: C (iron)
Explanation: The infant has neonatal hemochromatosis. At the white arrows (and elsewhere) are hemosiderin-laden macrophages. The blue arrow indicates fibrosis (secondary to the iron accumulation). The yellow arrows indicate extramedullary hematopoiesis. Cells with glucocerebroside, sphingomyelin, and cholesterol would be foamy in appearance.
Question 238
A forensic pathologist performs an autopsy on a 42-year-old male with a strong family history of sudden cardiac death who died unexpectedly five days after a minor surgical procedure. The pathologist identifies severe coronary artery atherosclerosis as the cause of death, but the region of the minor surgical procedure is shown below. Of the following, what was most likely present at the location of the yellow star at the time of the surgical procedure (the black line roughly outlines the rest of the pathologic process)?
A. A neoplasm
B. Deposits of hemosiderin
C. Aggregates of lymphocytes
D. Sheets of neutrophils
E. Parasites
Answer for Question 238
Answer: D (Sheets of neutrophils).
Explanation: The patient had an abscess. The area of the star is the cavity, and would have been filled with neutrophils, which would be cleaned out by surgical debridement. Now the cavity contains granulation tissue. At the edge of the cavity is a thick rim of fibrosis (outlined in white). Abscesses often have a thick fibrous rim.
Question 239
A 64-year-old male with a long-standing history of diabetes mellitus underwent an amputation of the distal portion of the right foot. Six months previously, he had undergone an amputation of the great toe and 2nd digit of the same foot. Of the following, what has occurred at the site of the first amputation?
A. Scarring by primary intention
B. Scarring by secondary intention
C. An abscess
D. Ulcer
E. Foreign body granulomas
Answer for question 239
Answer: D (Ulcer)
Explanation: Because of damage to nerves, diabetics do not feel injury to their feet, and because of damage to the blood vessels, when injury occurs, it often does not heal. At the location of the previous amputation is a deep cavitary defect in the skin–there is no scar. Diabetics often develop ulcers on the toes and foot, and, after an amputation, may not be able to heal at the site of the surgical resection, also allowing an ulcer to develop. Repeat amputations are common.
Question 240
A 34-year-old male with recently diagnosed AIDS secondary to an untreated HIV infection presents to the emergency room with complaints of malaise and decreased urine production. Laboratory testing reveals an elevated BUN and creatinine. The image illustrates the etiology of his renal abnormalities. Of the following, what is the most likely cause?
A. Cryptococcus neoformans
B. Staphylococcus aureus
C. Mycobacterium tuberculosis
D. Entamoeba histolytica
E. Cytomegalovirus
Answer for Question 240
Answer: E (Cytomegalovirus).
Explanation: The image is that of a large cell (the “megalo”) with the characteristic intranuclear inclusion of CMV; also seen are intracytoplasmic inclusions (which are not as commonly found on histologic examination as the intranuclear inclusions). The inclusion is due to a cytopathic effect produced by the virus. Cowdry A inclusions due to HSV infection look the same (i.e., an intranuclear inclusion with a clear halo), but the cells affected are not enlarged. CMV often affects endothelial cells and can cause infarcts of organs.
