ABPath Anatomic Pathology 3 — Questions and Answers
Question 1: Which marker is a sensitive indicator of vascular/endothelial differentiation?
- CD31 (Correct answer)
- CK7
- CDX2
- GFAP
Correct answer: CD31
CD31 is a highly specific and sensitive endothelial marker used in vascular tumors.
Question 2: Barrett esophagus is defined histologically by replacement of squamous epithelium with:
- Transitional epithelium
- Intestinal-type columnar epithelium with goblet cells (Correct answer)
- Keratinizing squamous cells
- Ciliated respiratory epithelium
Correct answer: Intestinal-type columnar epithelium with goblet cells
Barrett esophagus shows intestinal metaplasia with goblet cells in the distal esophagus.
Question 3: Which tumor characteristically shows a 'starry sky' appearance on low power?
- Burkitt lymphoma (Correct answer)
- Small cell carcinoma
- Chronic lymphocytic leukemia
- Hodgkin lymphoma
Correct answer: Burkitt lymphoma
Tingible-body macrophages among densely packed cells create the starry sky pattern in Burkitt lymphoma.
Question 4: Councilman (apoptotic) bodies are typically seen in:
- Renal tubules
- Viral hepatitis (Correct answer)
- Alveolar walls
- Cardiac myocytes
Correct answer: Viral hepatitis
Councilman bodies are apoptotic hepatocytes seen in viral hepatitis and yellow fever.
Question 5: Which immunostain is the most widely used marker for gastrointestinal stromal tumors (GIST)?
- S100
- CD117 (c-KIT) (Correct answer)
- Desmin
- TTF-1
Correct answer: CD117 (c-KIT)
Most GISTs express CD117 (c-KIT), reflecting activating KIT mutations.
Question 6: Caseating granulomas are most characteristic of infection with:
- Staphylococcus aureus
- Mycobacterium tuberculosis (Correct answer)
- Escherichia coli
- Candida albicans
Correct answer: Mycobacterium tuberculosis
Caseating (necrotizing) granulomas are the hallmark of tuberculosis.
Question 7: Which stain best demonstrates iron (hemosiderin) in tissue?
- Prussian blue (Correct answer)
- Congo red
- Silver stain
- Oil red O
Correct answer: Prussian blue
Prussian blue (Perls) stain highlights iron deposits as blue.
ABPath Anatomic Pathology 3
Which marker is a sensitive indicator of vascular/endothelial differentiation?