Partial LN involvement by FL. (A-B) In distinction from FLIS, the follicles are expanded in size (A), and clustered in 1 portion of the LN, as highlighted by CD20 immunohistochemistry (B). (C) CD10 staining shows that the margins of the atypical follicles are slightly blurred and not sharply defined. (D) The BCL2 stain is more variable in intensity than is typical for FLIS. Original magnification ×20.