Discordant histology vs discordant clonality. For patients with DLBCL at a nodal site, lymphomatous BMI may be either histologically concordant large B-cell involvement or histologically discordant small B-cell involvement, which suggests an indolent BCL involving the BM. Histologically discordant BMI may be either clonally related or clonally unrelated to the nodal DLBCL with molecular analysis.