Welcome to the twentieth part of a series on Hemato-oncology.
Question: Dr. Chiragbhai, thank you for explaining us about CML – chronic myeloid leukemia, the first disease to have underlying genetic defect identified and then a medicine developed based on that target. Also, the CML tree is a wonderful way of explaining pathophysiology and the goal of therapy.
Now can you tell us something about the second type of chronic leukemia i.e. CLL – chronic lymphocytic leukemia.
Answer: Yes, thank you for your interest and thank you readers for your feedback.
CLL as we learned in medical school is generally an indolent disease. However, there are few people who progress fast. This is an interesting disease as it is now officially considered a lymphoma, and yet is named as leukemia. Also, most readers may be aware of Rai staging system for CLL, but may not know that this system was developed by Dr. Kanti Rai, who became a doctor in India and then settled in USA. He has done a lot of pioneering work on CLL, and is still one of the most respected hematologists in USA.
Que: How do patients present with this type of leukemia or should we say lymphoma?
Ans: Yes, we should probably start saying lymphoma. Well most patients actually do not present with any symptoms. Increasingly people are diagnosed on routine laboratory tests done for health check up or for unrelated symptoms or preoperative work up.
High lymphocyte percentage and often high total white cell count as well are noted, and evaluation leads to diagnosis of CLL. Most patients are not ready to believe as they are absolutely asymptomatic at this stage, known as Rai stage 0.
Some present with weakness, fever, lymphadenopathy, splenomegaly.
Que: Ok. So how do you confirm the diagnosis?
Ans: Once high lymphocyte count is detected, one should rule out obvious infections based on history and examination. Then repeat count after few days to weeks, if patient is not anxious. When it is obvious that patient is not suffering from any viral or other obvious self limiting infection, next best test is Immunophenotyping by Flow Cytometry, from peripheral blood.
This is the CONFIRMATORY test. Bone marrow aspiration or biopsy is not required for this diagnosis. Also, CLL diagnosis is not possible without immunophenotyping. There is no value of performing other indirect tests, as many of them have overlapping features with other lymphomas.
A small number of patients have absolute lymphocyte count higher than normal limit (and monoclonal by flow cytometry), but less than 5000, and are otherwise normal and asymptomatic. Such patients are diagnosed as MBL – monoclonal B lymphocytosis. This condition is similar to MGUS in myeloma, which is left untreated. A small number develop CLL over many years.
Dr. Chirag A. Shah; M.D. Oncology/Hematology (USA), 98243 12144, 98988 31496
Diplomate American Board of Oncology and Hematology. Ahmedabad. firstname.lastname@example.org
Shyam Hem-Onc Clinic. 402 Galaxy, Near Shivranjani, Opp Jhansi ki Rani BRTS, Ahmedabad. www.shyamhemoncclinic.com