BMS Pathology and Microbiology 4 — Questions and Answers
Question 1: At autopsy, diffuse alveolar damage with hyaline membrane formation is the hallmark lesion of:
- Acute respiratory distress syndrome (Correct answer)
- Emphysema
- Pulmonary fibrosis
- Lobar pneumonia
Correct answer: Acute respiratory distress syndrome
ARDS is characterized histologically by diffuse alveolar damage with protein-rich hyaline membranes lining alveolar ducts.
Question 2: Which type of emboli is most commonly found at autopsy in cases of sudden death following long bone fractures?
- Fat emboli (Correct answer)
- Thromboembolism
- Air emboli
- Amniotic fluid emboli
Correct answer: Fat emboli
Long bone fractures release bone marrow fat globules that can embolize to the pulmonary vasculature, causing fat embolism syndrome.
Question 3: Pseudomembranous colitis, diagnosed at autopsy, is most commonly caused by:
- Clostridioides difficile (Correct answer)
- Salmonella typhi
- Campylobacter jejuni
- Shigella dysenteriae
Correct answer: Clostridioides difficile
C. difficile toxins A and B cause mucosal damage and characteristic pseudomembrane formation, usually following antibiotic therapy.
Question 4: Which staining method best demonstrates fungal organisms such as Histoplasma capsulatum in postmortem tissue?
- Gomori methenamine silver (GMS) (Correct answer)
- Gram stain
- Congo red
- Prussian blue
Correct answer: Gomori methenamine silver (GMS)
GMS stain colors fungal cell walls black against a green background, making it the standard method for detecting fungi in tissue.
Question 5: The presence of Negri bodies in Purkinje cells of the cerebellum at autopsy is diagnostic of:
- Rabies (Correct answer)
- Herpes simplex encephalitis
- Creutzfeldt-Jakob disease
- West Nile encephalitis
Correct answer: Rabies
Negri bodies are eosinophilic intracytoplasmic inclusions containing viral nucleocapsid material, pathognomonic for rabies virus infection.
Question 6: Which postmortem artifact can mimic ante-mortem petechial hemorrhage in the conjunctiva?
- Postmortem lividity
- Tardieu spots (Correct answer)
- Vitreous potassium increase
- Corneal clouding
Correct answer: Tardieu spots
Tardieu spots are subpleural and conjunctival petechiae from asphyxia but can also occur postmortem from mechanical pressure, potentially mimicking ante-mortem findings.
Question 7: A decedent's kidney shows bilateral cortical pallor with medullary hyperemia at autopsy. This pattern is most consistent with:
- Acute tubular necrosis (Correct answer)
- Chronic pyelonephritis
- Renal cell carcinoma
- Polycystic kidney disease
Correct answer: Acute tubular necrosis
ATN from ischemia or nephrotoxins causes tubular epithelial death with cortical pallor and preserved medullary blood flow.
BMS Pathology and Microbiology 4
At autopsy, diffuse alveolar damage with hyaline membrane formation is the hallmark lesion of: