Question 216
A 43-year-old male with an HIV infection secondary to intravenous drug use and sharing of needles and who has been non-compliant with his anti-viral drug regimen presents to the emergency room because he has had a fever for several days and has felt tired. He occasionally coughs, but does not produce much sputum. The image illustrates the cause of his disease process. Of the following, what is the most likely diagnosis?
A. Coccidioides immitis
B. Blastomyces dermatitidis
C. Aspergillus fumigatus
D. Mycobacterium tuberculosis
E. Pneumocystis jiroveci
Answer for Question 216
Answer: E (Pneumocystis jirovecki)
Explanation: The stain is a GMS (Grocott methenamine silver) stain, which will stain a fungus black. Pneumocystis is described as being cup-shaped (blue arrow).
Question 217
A 51-year-old male with a history of multiple sclerosis required prolonged intubation following a cardiac arrest after aspiration of food. Although he was bed bound and expected to die, when he did, his distraught family requested an autopsy. The pathologist identified the lesion illustrated below. Of the following, what was the most likely etiology?
A. HIV infection
B. Trauma
C. Prolonged intubation
D. Retained foreign body
E. Gastric reflux
Answer for Question 217
Answer: C (Prolonged intubation)
Explanation: The pathologic lesion at the arrow is a fistula (an abnormal connection between two organs, or an organ and the skin–enterocutaneous fistulas can result from colon cancer). In this case, the fistula is between the esophagus and the trachea. A fistula results when a non-healing infection or another chronic process causes two organs to stick together and a path to develop between them. Neoplasia is a cause of fistulas also. Prolonged intubation could allow for necrosis and continued inflammation and the potential development of a fistula.
Question 218
A 53-year-old female presents to her family physician. Over the past year, she has noticed frequent burning and itching of her eyes, and, within the past several months, has had some difficulty eating, in that the swallowing of food is difficult. She is also experiencing some stiffness in the joints of her left and right hands. The image illustrates the pathologic condition causing her symptoms. Of the following, what is the antigen against which the antibodies causing her disease react?
A. Ribonucleoprotein
B. DNA
C. Centromeric protein
D. RNA
E. Phosphatidylcholine
Answer for Question 218
Answer: A (Ribonucleoprotein)
Explanation: The dry mouth and dry eyes, and the accompanying stiffness of the joints (i.e., which can occur in rheumatoid arthritis) is characteristic of Sjogren syndrome. The two antibodies characteristically seen in Sjogren syndrome are anti-Ro/SS-A and anti-La/SS-B, which are both ribonucleoproteins.
Question 219
A 43-year-old female with a history of sarcoidosis dies in a motor vehicle accident. The pathologist who performs the autopsy samples the lung for histologic examination and identifies the pathologic finding illustrated in the below image. What cell type is indicated by the yellow arrow?
A. A B lymphocyte
B. A T lymphocyte
C. A macrophage
D. An eosinophil
E. A plasma cell
Of the following, which cytokine played the largest role in activating the cell type indicated by the yellow arrow?
A. IL-1
B. TNF-β
C. Major basic protein
D. IFN-γ
E. IL-13
Answer for Question 219
Answers: C (A macrophage) and D (IFN-γ)
Explanation: The image illustrates a granuloma. The cell at the yellow arrow is an activated macrophage (i.e., a large amount of cytoplasm and the cell is referred to as epithelioid). Macrophages are activated by IFN-γ, which is secreted by T lymphocytes. The white arrows are lymphocytes and the blue arrows are multi-nucleated giant cells (produced by fusion of the activated macrophages). Sarcoidosis, among other conditions, is associated with granulomas.
Question 220
A 63-year-old male with a history of hypertension for 27 years and a 35 pack-year smoking history, is working in his backyard trimming the hedge when he suddenly losses his balance and falls down. He is unable to stand and calls for his wife to help him. Emergency medical services is called and he is transported to the hospital. Imaging studies 2 hours later reveal a pathologic lesion. The photomicrograph below illustrates the microscopic changes associated with the pathologic lesion identified on imaging. Of the following, where was the lesion located.
A. Frontal lobe
B. Parietal lobe
C. Midbrain
D. Cerebellum
E. Medulla
What pathologic process is occurring?
A. Dystrophic calcification
B. Caseous necrosis
C. Coagulative necrosis
D. Liquefactive necrosis
E. Fat necrosis
Answer for Question 220
Answer: Cerebellum (D) and Coagulative necrosis (C)
Explanation: Although review books describe coagulative necrosis as occurring below the neck and liquefactive necrosis as occurring above the neck (i.e., the brain). After a stroke or other ischemic injury to the brain, coagulative necrosis develops first (i.e., increased eosinophilia of the cells and loss of nuclear and cellular basophilia, but with retention of architecture) followed quickly by liquefactive necrosis. With coagulative necrosis, the architecture is intact and identifiable, even though the cells are dead. In the image on the left below, the blue arrow is the granular layer, the black arrows are the necrotic Purkinje cells, and the red arrow is the molecular layer.
