In order to diagnose CLL and rule out other types of leukemia, other complementary tests should be performed such as

• physical examination and review of the patient's medical history.
• Laboratory tests à blood count to establish blood-cell counts and biochemical studies to check kidney and liver function, levels of β2-microglobulin and serology for HIV and hepatitis B and C. Diagnosis is performed using flow cytometry.
• Imaging tests à CT and MRI are not performed routinely for this disease.
• Bone-marrow biopsy and aspiration à The aspirate is used to determine whether there is lymphoid infiltration of over 30%, and the biopsy shows the pattern of infiltration, which will provide us with a prognostic value.

Once the above-mentioned additional tests are done, your medical team will set out to classify the disease based on its location and where it is spreading to. Classification helps in planning and deciding on the most appropriate treatment.