Abstract Context.—The World Health Organization classification recommends categorizing grade 3 follicular lymphomas based on the presence of centrocytes (grade 3A) or of sheets of centroblasts (grade 3B). The clinical significance of this practice is not known. Objective.—To determine whether grade 3 follicular lymphoma subtype is associated with prognosis. Design.—Multi-institutional retrospective case series. Main Outcome Measure.—Overall survival. Results.—Forty-five cases of grade 3 follicular lymphoma without diffuse large B-cell lymphoma were studied (35 cases of grade 3A, 10 cases of grade 3B) from 21 men and 24 women (median age, 67 years; mean age, 63.8 years; range, 26–86 years). Follow-up information from the time of diagnosis was available in all patients, with a median follow-up time of 24 months (mean, 34 months; range, 2– 115 months). Treatment information was available in 40 patients. There was no difference in age (P = .45, Wilcoxon test) or stage (P = .76, Fisher exact test) between pati...