I had the FISH test done in September 2007, and it showed normal. The rest of the tests showed CLL. Why did this test not show CLL, and should I get it done again?

Fluorescence in situ hybridization (FISH) looks for very specific large genetic abnormalities in the DNA inside the cancer cells. It is important to know about some of these large gene changes because they have both impact on how your disease is treated, and how fast it might progress.

However, a person with chronic lymphocytic leukemia can have normal results on the FISH test, meaning that the changes in the genes simply cannot be detected with this method. Your doctor or oncologist might have FISH test performed again on your CLL cells if there is change in the status of your disease (recurrence or increased aggressiveness, for example).

Learn more in the Everyday Health Leukemia Center.