Answer and Discussion of Quiz Set: A-004
2. Which of the following immunohistological stains would most likely be negative in Kaposi sarcoma?
A. HHV8
B. CD31
C. CD34
D. S-100
E. D2-40
Answer and Discussion:
The answer is (D).
Kaposi sarcoma usually shows positive immunoreactivity for vascular endothelial
markers (CD31, CD 34, and factor VIII), and HHV-8. Report showed that Kaposi
sarcoma was also positive for D2-40, a marker of lymphatic differentiation.
Immunohistochemical detection of HHV-8 LNA-1 and D2-40 could be useful tools to
differentiate Kaposi sarcoma from other vascular tumors.