Diagnosis of Hodgkins Lymphoma
Hodgkins lymphoma must be singled out from diseases with similar symptoms, such as benign lymph node swellings, caused by infections, and also from other forms of cancer.
Blood tests are carried out as part of investigations to detect lymphoma. However, these tests are not totally reliable and have to be supported by other tests. Blood tests are done for the following reasons:
► Count the red and white blood cells and platelets. Hodgkins lymphoma can cause reduction in the blood cell numbers.
► In Hodgkins disease, the malignant cells, now identified to be a type of B-lymphocytes, are called Reed-Sternberg cells. (RSC), after the two doctors who first identified and described them. When seen under the microscope, they look different from non-Hodgkins lymphoma cells and other cancers.
► Blood tests are also done to evaluate the changes, brought on by the disease, in the functions of certain vital organs.
Lymph node biopsy- For a definitive diagnosis, a sample of the lymph node tissue is removed (biopsy) for pathological evaluation in a laboratory. This microscopic analysis helps to diagnose the lymphoma, to assess its type and stage and also to plan the type of treatment.
Staging the Disease before commencing the treatment is most crucial and for this various imaging investigation are used. Sometimes surgery maybe necessary.
Imaging studies,- such as Chest X-ray, Computed Tomography (CT or CAT) scan or, Magnetic Resonance imaging (MRI) or Positron Emission Tomography or a Gallium scan can be done.
Of all the imaging studies, Positron Emission Tomography (PET) scanning is the most sensitive in determining the stage of the disease and also on follow up to look at the response to treatment. The advantage with PET scan is that it gives images of areas which are still living and differentiate it from areas which are dead or scarred after the treatment.
In the Gallium scanning that is used for staging and to look at the effects of treatment, a small dose of Gallium (radioactive material) is first injected into the bloodstream and a special camera is used to look at its uptake by living tissues after a period of 3 to 4 days.
If staging is required to stage the disease, spleen is removed and biopsy of the liver is done to look at its spread. This is doine either by open technique or laparoscopically.
Lumbar puncture or a spinal tap may be done to see if lymphoma has spread to the central nervous system.
Depending on these tests the doctor will:
► Confirm the diagnosis
► Identify the stage of the disease, how far it has spread within the body
► Assess Degree and speed of growth of the tumor
► Assess the risk and the patient’s chances of survival