Lymphomas are a large group of blood cancers in which there is a malignant proliferation of lymphoid-derived cells within extramedullary lymphatic and extralymphatic tissues.
- They generally create swellings, hence the “oma” in lymphoma.
- Compared to leukemias (where cells are in the bone marrow and blood), lymphomas are found in lymphatic and extra-lymphatic tissues with a relatively scarce appearance of malignant cells in the circulation.
- Generally classified into Hodgkin's and Non-Hodkin's lymphomas.
Non-Hodkin's lymphomas
- Generally, NHLs are divided into indolent (slow-growing but incurable) and aggressive (rapidly-growing but curable).
- Waldeyer's tonsillary ring and diffuse lymphadenopathy, as well as extra lymphatic involvement (bone marrow, liver, GI, skin, brain, testis), are common.
- Associated with a variety of infections (EBV, HHV8, HTLV1, HIV).
Cells
85% are B-cell tumors; 15% are T and NK.
- B-cell lymphomas can be divided into those resembling precursor B cells, those