CD23 expression in follicular lymphoma: Clinicopathologic correlations

Follicular lymphoma (FL) is typically a CD10+/ CD5-/FMC-7+ B-cell lymphoma with variable CD23 expression. The clinical significance of CD23 expression in FL is uncertain. We studied the expression of CD23 by flow cytometry in 69 lymph nodes (LNs) and correlated it with pathologic and clinical parameters. Of 69 FLs, 48 (70%) were CD23+. Grade 3 FLs were CD23- more often (12/16 [75%]) than grade 1 and 2 cases (9/53 [17%]; P < .001). CD23 expression was more common in FLs in inguinal LNs than in other sites: 20 of 23 (87%) vs 28 of 46 (61%; P = .029). Overall survival (P = .002) and event-free survival (P < .0001) were longer in the CD23+ group than in the CD23- FLs. Our study shows that grade 3 FLs are more often CD23- than lower grade FLs and that FLs in inguinal LNs are more frequently CD23+ than in LNs from other sites. Furthermore, our findings also indicate that survival is significantly better in CD23+ FLs.