Spleen	•White pulp atrophy or depletion •Absence of marginal zones •Increased ratio of red: white pulp •Lymphoplasmacytic infiltrates •Immunoblast infiltrates •Red pulp necrosis •Red pulp congestion •Hemorrhage	•Defective germinal centers •Absence of TFH cells •Altered lymphocyte subsets •Hemophagocytosis •Extramedullary megakaryocytes
Lymph nodes	•Lymphocyte depletion •Absent or hypoplastic germinal centers •Sinus histiocytosis •Increased immunoblasts and plasmablasts •Vascular congestion with vascular transformation of sinuses •Hemorrhage