Lymphomas Flashcards
Reed-Sternberg cells are derived from ____.
Reed-Sternberg cells are derived from germinal center B cells.
The inflammatory response to Reed-Sternberg Cells (RSC) in Hodgkin Lymphoma is the product of ___.
The inflammatory response to Reed-Sternberg Cells (RSC) in Hodgkin Lymphoma is the product of cytokines expressed by the RSC.
Most Non-Hodgkins lymphomas involve. . .
. . . recombination involving the IgH promoter
Follicular lymphoma
- Arises in germinal center of lymphoid follicle
- Recombination of IgH promoter and Bcl2
- Oncogenesis by “failure to die”
Diffuse large B cell lymphoma
- IgH promoter and Bcl6 recombination
Burkitt’s Lymphoma
- Very deadly - put down your sandwich
- IgH promoter and myc recombination
- Large, irregular, highly euchromatic nuclei
SVC syndrome
Compression of the SVC by a retrosternal mass may result in facial redness and facial edema.
Secondary symptoms of lymphoma
- B symptoms
- Immunosuppression
- Loss of tolerance
HHV-8 (Kaposi’s Sarcoma Virus)
Strongly associated with primary effusion lymphoma, a rare, aggressive, B-cell lymphoma that arises within chronic effusions, typically in the pleural or peritoneal spaces.
HTLV-1
Human T-cell Lymphotrophic Virus-1
A retrovirus directly associated with adult T-cell leukemia/lymphoma (ATLL).
Much like HIV, integrates into CD4 T cell DNA.
HIV and lymphomas
While HIV itself does not cause lymphomas directly, it degrades the immunity to existing viruses within hosts that can cause lymphoma, like EBV. It also causes a strong mononucleusos-like reaction in its acute phase, which puts stress on germinal centers and may precipitate a B cell lymphoma.
It is not at all uncommon for someone infected with HIV with poor management to develop an EBV-positive tumor from an EBV infection in their distant past that was previously under check by their immune system.
H. pylori and lymphoma
H. pylori infection causes chronic gastric inflammation that may precipitate a gastric extranodal marginal zone lymphoma, aka MALT lymphoma.
This mechanism is similar to how MALT lymphoma is produced in Sjogren syndrome and Hashimoto’s thyroiditis.
CLL / SLL
Chronic lymphocytic leukemia / small lymphocytic lymphoma
Two manifestations of the same disease. Unlike many lymphomas, does not involve translocation or the IgH promoter.
Characterized by overwhelming numbers of small, fragile lymphocytes with packed chromatin and scant cytoplasm either in peripheral blood or in bone marrow, with “proliferation centers” in the lymph nodes. Prolymphocytes are actively dividing cells in proliferation centers have especially large nuclei with very prominent nucleoli. Image of proliferation center is shown below.
Diagnosing CLL/SLL
- CLL will present with lymphocytosis while otherwise asymptomatic
- SLL will often present with diffuse lymphadenopathy while otherwise asymptomatic
- Unlike most cancers, does not produce B symptoms. Thus, associated fevers should be assumed to be due to infection
- Diagnosis established by flow cytometry
- Tissue biopsy of marrow or lymph node usually unnecessary for CLL, but often is for SLL.
Flow features of CLL/SLL
- pan-B cell markers: CD20, CD23
- CD5, usually T cell marker, misexpressed in CLL/SLL
- Exhibit kappa/lambda clonality
- Usually low level of surface IgM
When to Treat CLL/SLL
- As many as 60% of patients do not need treatment, but indications for those that do include:
- Cytopenias (myelophthesis)
- Symptomatic lymphadenopathy and organomegaly
- Symptomatic autoantibodies
- Appearance of B symptoms (not usually present in this disease)
- Richter transformation (5% of patients, transformation to an aggressive lymphoma resembling diffuse large B-cell lymphoma, poor prognosis)