Lymphoid neoplasms with plasmablastic differentiation
Lymphoid neoplasms with plasmablastic differentiation were classified by the World Health Organization, 2017 as a sub-grouping of several distinct but rare lymphomas in which the malignant cells are B-cell lymphocytes that have become plasmablasts, i.e. immature plasma cells. Normally, B-cells take up foreign antigens, move to the germinal centers of secondary lymphoid organs such the spleen and lymph nodes, and at these sites are stimulated by T-cell lymphocytes to differentiate into plasmablasts and thereafter mature plasma cells. Plasmablasts, and to a greater extent, plasma cells make and secrete antibodies that bind the antigens to which their predecessor B-cells were previously exposed. Antibodies function, in part, to neutralize harmful bacteria and viruses by binding antigens that are exposed on their surfaces. Due to their malignant nature, however, the plasmablasts in lymphoid neoplasms with plasmablastic differentiation do not mature into plasma cells or form antibodies but rather uncontrollably proliferate in and damage various tissues and organs. The individual lymphomas in this sub-group of malignancies have heterogeneous clinical, morphological, and gene findings that often overlap with other members of the sub-group. In consequence, correctly diagnosing these lymphomas has been challenging. Nonetheless, it is particularly important to diagnose them correctly because they often have very different prognoses and treatments. The lymphoid neoplasms with plasmacytic differentiation are:
1) Plasmablastic lymphoma: The most common of these lymphoid neoplasms.
4) Primary effusion lymphoma, human herpes virus-negative: Also termed primary effusion lymphoma, type II; it is characterized by having effusions in body cavities.
5) Anaplastic lymphoma kinase-positive large B-cell lymphoma: An anaplastic large cell lymphoma in which the malignant cells have plasmablastic features and a distinguishing mutation in the anaplastic lymphoma kinase gene.
