Most non-Hodgkin lymphomas affect B cell lymphoid cells, but some affect T cell lymphoid cells.
The most important distinction, in terms of treating each patientâ€™s lymphoma, is the speed at which the tumours grow. Fast growing tumours are called aggressive or high grade, lymphomas. About half of all non-Hodgkin lymphoma patients have an aggressive lymphoma called diffuse large cell B lymphoma. Aggressive lymphomas are easier to treat and cure, but need immediate treatment.
Slow growing tumours are called indolent or low grade, lymphomas. The most common form of indolent lymphoma is a type called follicular lymphoma, which affects about one in five of all patients with non-Hodgkin lymphoma.
Patients with indolent lymphomas may not need any treatment, and can lead a good quality of life without treatment for many years. Indolent lymphomas can, rarely, also develop into aggressive lymphomas.