A lymphoma is a tumour of lymph nodes. It is a malignant clonal expansion of lymphocytes and generally of T-lymphocyte or B-lymphocyte origin, although haematolymphoid cells of other derivation are also referred to as lymphoma (e.g. NK cell lymphoma).
Leukaemia indicates the presence of clonal haematolymphoid cells in the blood. This can overlap with lymphoma and the same disease may be classified into lymphoma or leukaemia depending on which component is predominant (e.g. chronic lymphocytic leukaemia vs small cell lymphoma).
It is usually suspected as part of the clinical assessment for non specific symptoms or lymphadenopathy.
- Routine bloods indicated by presentation
- Imaging based on symptoms
- Biopsy Tissue required for diagnosis. Morphology + molecular + cytogenetics.
- FBC (to identify leukaemic component; cytopenias may reflect bone marrow disease)
- LDH (rapidly turning over cells release LDH)
- CXR (if chest disease suspected)
- Cross-sectional imaging is generally used for staging, e.g. CT or CT/PET
- Hodgkin's disease (HD)
Non-Hodgkin's lymphoma (NHL) is such a catch all that it is uninformative and better sub-divided. Even a division into B-cell non-Hodgkin’s lymphoma and T-cell non-Hodgkin’s lymphoma is pretty uninformative.
Indeed the subdivision in terms of diagnosis, prognosis and treatment can be exceedingly fine and is evolving with further cytogenetic refinement. Classification is based mainly on the WHO 'blue book':