The Sentient Propagation-Reactive B Cell-Rich Lymphoid Proliferation

Abstract

Reactive B cell-rich lymphoid proliferation is a heterogeneous group of non-neoplastic lymphoid cell proliferation recapitulating diverse B cell lymphomas. The lesion is commonly categorized as nodal and extra-nodal follicular proliferations, nodal and extra-nodal nodular proliferations or nodal and extra-nodal immunoblastic proliferations. Florid follicular hyperplasia is comprised of quantifiably enhanced, disseminated primary and secondary lymphoid follicles with irregular outlines. Hyperplastic Germinal Centres (GCs) are comprised of admixed centroblasts and centrocytes, reactive T cells, Follicular Dendritic Cells (FDCs) and tingible body macrophages. Lymph node architecture depicts lymphoid follicles comprised of cells expressing B cell antigens wherein primary follicles are pre-eminently constituted of small lymphocytes BCL2+, BCL6- and CD10- immune reactivity. Progressive Transformation of Germinal Centre (PTGC) is constituted of singular or few enlarged lymphoid follicles of 4x to 5x magnitude wherein mantle zone cells display extensive invagination into adjacent germinal centres. Hyaline Vascular Castleman’s Disease (HVCD) delineates innumerable lymphoid follicles confined to the lymph node cortex and medulla or diverse extramedullary sites.