Flow diagram depicting the diagnosis of IVLBCL using RSB. Among the 111 patients, 27 had IVLBCL lesion detected on the first RSB; the remaining 84 did not have any IVLBCL lesions. Two patients with negative first RSB findings subsequently had IVLBCL lesions detected on their second and third RSBs. Among the 82 remaining patients with negative RSB, 5 were diagnosed with IVLBCL lesions using bone marrow biopsy (n = 4) and adrenal biopsy (n = 1). One patient with positive RSB findings had concomitant large cardiac B-cell lymphoma and adrenal swelling and therefore was not considered have IVLBCL based on the World Health Organization definition of IVLBCL. In total, 33 patients were diagnosed with IVLBCL; the remaining 78 patients tested negative for IVLBCL. POEMS, polyneuropathy, organomegaly, endocrinopathy, monoclonal paraprotein, skin changes syndrome.