I was rather surprised to hear Dr John Byrd mention a lymphocyte count of a million in the presentation he gave last May, see:
While I've quite often heard of people with counts in the hundreds (or hundred thousands in the USA) and still on watch and wait (remember for a CLL diagnosis you only need to be above 5 (5,000 in the USA), today I came across Dr Hamblin's blog on Leukostasis (see later for definition) and thrombosis (blood clots) in CLL where he discusses whether there are any risks associated with having high white cell counts in CLL patients. He opens with "The highest white count that I have seen in CLL is 800,000/cu mm though Tom Kipps told me of a patient with 1,400,000/cu mm. The odd thing is that neither of us has ever seen leukostasis in CLL. This is the condition, often seen in myeloid malignancies where sludging of white cells in blood vessels cuts off the circulation to a particular organ."
In short, because the B-lymphocytes in CLL are smaller than can occur with other leukaemias, having health problems due to the absolute volume of lymphocytes in the blood isn't something we need be too concerned about.
Hallek says it well in his paper "Guidelines for the diagnosis and treatment of CLL":
"Patients with CLL may present with a markedly elevated leukocyte count; however, the symptoms associated with leukocyte aggregates that develop in patients with acute leukemia rarely occur in patients with CLL. Therefore, the absolute lymphocyte count should not be used as the sole indicator for treatment."
What is more important is how quickly the lymphocytes are growing (the doubling time) and even this isn't something to be concerned about until your lymphocyte count exceeds 30. Knowing this would have saved me some anxious moments a few years back when my counts changed fairly rapidly as I went from a SLL to a CLL presentation.
Chaya Venkat has covered how to understand your blood tests and how to monitor changes in your Absolute Lymphocyte Counts in her usual thorough manner in her article below:
In particular, read the section "Treating the numbers” is not smart"
I hope this reassures those newly diagnosed with high lymphocyte counts. It can be rather confronting to find the normal ALC range is between 1 and 3.5 (or 1,000 and 3,500 in the USA) and find your count is 20, 30, 50 or more! (or 20,000, 30,000 or 50,000 in the USA.)
Update May 2015
Since writing this, I've noticed that it is becoming more common among world renown CLL experts to more openly question the validity of a decision to treat purely on the basis of a high lymphocyte count. Basically the prevailing wisdom gained from observing thousands of CLL patients is that if a patient is otherwise well, just keep monitoring the patient.
Chris (Cllcanada) has just posted about a paper from the study of Israeli patients that further presents this case:
and the paper: ar.iiarjournals.org/content...
From the discussion section of that paper: "Although hyperleukocytosis is an obvious reflection of the tumor burden in CLL, it is not considered a prognostic parameter in CLL and does not necessarily dictate treatment decisions."
"In general, symptomatic hyperleukocytosis is more common in acute leukemias but several reports have concentrated on cases of CLL presenting with symptoms related to leukostasis. In CLL, cellular hyperviscosity and leukostasis (caused by the formation of WBC aggregates and thrombi) are rare complications, probably due to the small size of circulating lymphocytes and their rheological characteristics, which are very different from those of neutrophils. Occasionally, cases of CLL with extreme hyperleukocytosis >1000×10^9/l have been reported to develop neurological abnormalities, retinal hemorrhages, lung infiltrates or thrombosis."