What percentage of malignant cells typically express CD10 in follicular lymphoma?

• A. 0%
• B. 30%
• C. 70%
• D. 100%

Answer: (C)

In follicular lymphoma, it is characteristic for the majority of malignant B cells to express CD10. This protein is a marker commonly found on germinal center B cells and is often associated with follicular structures in lymphoid tissues. The expression of CD10 is a defining feature of follicular lymphoma, confirming its derivation from the germinal center B-cell lineage.

Typically, studies show that around 70% of malignant cells in follicular lymphoma express CD10. This expression helps in the diagnosis and classification of the lymphoma type and can be an important factor in determining the treatment course. Given the established association of CD10 expression with follicular lymphoma pathology, the correct answer reflects the common phenotypic characteristic of these malignant B cells.