<unk>  <unk>  is a type of large B-cell lymphoma recognized by the World Health Organization (WHO) in 2017 as belonging to a subgroup of lymphomas termed lymphoid neoplasms with<unk>  differentiation. The other lymphoid neoplasms within this subgroup are:<unk>  plasma cell lymphoma (or the plasmacytoma variant of this disease); primary effusion lymphoma that is Kaposi's sarcoma-associated herpesvirus positive or Karposi's sarcoma-associated Herpesvirus negative; anaplastic lymphoma kinase-positive large B-cell lymphoma; and human herpesvirus 8-positive diffuse large B-cell lymphoma, not otherwise specified. All of these lymphomas are malignancies of plasmablasts, i.e. B-cells that have differentiated into plasmablasts but because of their malignant nature: fail to differentiate further into mature plasma cells; proliferate excessively; and accumulate in and injure various tissues and organs. The lymphomas in the lymphoid neoplasms with<unk>  differentiation sub-group that are not<unk>  have sometimes been incorrectly considered to be variants of<unk> . Each of the lymphomas in this subgroup of malignancies have distinctive clinical, morphological, and abnormal gene features. However, key features of these lymphomas sometime overlap with other lymphomas including those that are in this sub-group. In consequence, correctly diagnosing these lymphomas has been challenging. Nonetheless, it is particularly important to diagnose them correctly because they can have very different prognoses and treatments than the lymphomas which they resemble.<unk> s are aggressive and rare malignancies that usually respond poorly to chemotherapy and carry a very poor prognosis. They occur predominantly in males who have HIV/AIDS, had a solid organ transplant, or are immunosuppressed in other ways; ~5% of all individuals with<unk>  appear to be immunocompetent, i.e. to have no apparent defect in their immune system. The malignant plasmablasts in more than half the cases of<unk>  are infected with a potentially cancer-causing virus, Epstein Barr virus (EBV), and rare cases of<unk>  appear due to the<unk>  transformation of a preexisting low-grade B-cell lymphoma. One variant of<unk> , sometimes termed<unk>  of the elderly, has a significantly better prognosis than most other cases of<unk> . The development of this variant appears due, at least in part, to immunosenescence, i.e. the immunodeficiency occurring in old age.
Plasmablastic lymphoma
Diffuse large B-cell lymphoma
Mixed-cell lymphoma
Marginal zone B-cell lymphoma
Aggressive lymphoma
Gray zone lymphoma
Follicular lymphoma
Anaplastic large-cell lymphoma