SMZL : Bone Marrow
Splenic Marginal Zone Lymphoma (SMZL) - Bone Marrow Involvement: Bone marrow is almost always involved in SMZL. The tumor infiltrates may not be easily visualized on routine stains. CD20 immunostains show intertrabecular and intrasinusoidal lymphoid aggregates. Larger tumor nodules may have architecture similar to that seen in the splenic white pulp with residual germinal centers surrounded by neoplastic cells with marginal zone differentiation.
Image courtesy of: Sanam Loghavi, MD (@sanamloghavi); used with permission.