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6 slides generated from the cancer page, with a quiz from the open benchmark and speaker notes that cite the sources. Arrow keys move between slides; Print gives one slide per page.
An aggressive lymphoma whose cells have taken on the appearance of plasma cells, so they no longer carry the CD20 marker that most B-cell lymphoma treatments aim at. It most often starts in the mouth or jaw, and about half of people diagnosed with it have HIV.
What it is. A large B-cell lymphoma whose cells have travelled most of the way to becoming plasma cells, the antibody factories that B cells turn into at the end of their life. That matters practically rather than philosophically: a plasma cell has switched off CD20, so rituximab and the antibody treatments that follow it cannot see the tumour. Instead the cells carry plasma cell markers, CD138 and MUM1, and the diagnosis is made on that pattern together with a very high proliferation index.
Who gets it. In the largest United States analysis, 1,153 patients in SEER and 1,822 in the National Cancer Database diagnosed between 2010 and 2020, the incidence was 0.07 cases per 100,000 people a year, 77 per cent were men, and half had HIV. In an earlier SEER analysis of 248 treated patients, 82 per cent were men and 71 per cent were under 60, with the mouth and the gastrointestinal tract the commonest starting points at 23 and 19 per cent. It also occurs after organ transplant and in older people with age-related decline in immunity.
| Setting | Approach | Guideline |
|---|---|---|
| Making the diagnosis, and why it is missed | The cells look like plasma cells and the surface markers agree with that appearance, so the differential diagnosis includes myeloma with plasmablastic features rather than other lymphomas. What separates them is the clinical picture: a rapidly growing mass, usually in the mouth or jaw or the gut, in a younger person, often with HIV, with Epstein-Barr virus in the cells and a very high proliferation index. HIV testing belongs in every work-up. | not mapped |
| Treatment | Combination chemotherapy more intensive than standard immunochemotherapy, because there is no CD20 for rituximab to attach to, together with antiretroviral therapy where there is HIV. In the two large United States analyses, HIV status did not affect survival once treatment was given. Drugs used in myeloma, such as bortezomib and lenalidomide, have been added in case series on the basis of the phenotype rather than on randomised evidence. The regimens are in the treatment layer of this family and on the HIV-associated lymphoma page. | not mapped |