Considering the possible reasons for the discrepancy in all 23 cases, we saw very abundant T-cells (six cases, five of them GCB by IHC and ABC or unclassified by Lymph2Cx), poor fixation (three cases), expression of CD5 in neoplastic cells (three cases, all GCB by IHC and ABC by Lymph2Cx), anaplastic, immunoblastic/plasmablastic morphology (two cases, both GCB by IHC and ABC by Lymph2Cx). Here, CD5 is linked to aneurysmal bone cyst.