Is it possible to have bone marrow blasts in CMML without blasts in peripheral blood?

Question

Hello doctor,

I was initially diagnosed with AML at a hospital, but later the diagnosis was changed to CMML. Since then, I have been undergoing treatments of Decitabine every 28 days. Recently, I moved to another country and resumed my treatment. However, my platelets have not fully recovered to normal levels. During my last treatment, my platelets dropped to 23000, and even after a couple of weeks, they only rose to 33000. As a result, my doctor decided to halt the next Decitabine treatment and ordered a bone marrow biopsy to investigate further.

My concern is whether it is possible to have blasts in the bone marrow, such as 20% in AML, and not have blasts in the peripheral blood. Additionally, during the biopsy, my doctor attempted to obtain an aspirate three times but was unsuccessful, describing it as a dry tap. However, he was able to obtain a good bone marrow sample. This has left me quite worried. I would appreciate any advice or insights you may have on this matter.

Thank you.

Answer 1

Hello,

Welcome to icliniq.com.

I read your query and understand your concern.

For the diagnosis of acute leukemia, the blast count should be more than 20%. In cases of sub-leukemic or aleukemic leukemia, blasts may not be visible in the peripheral blood, even if the blast count in the bone marrow is more than 20%. Therefore, a bone marrow biopsy will help in confirming whether acute leukemia is present or not. In chronic leukemia, there is a possibility of a blast crisis, where chronic leukemia transforms into an acute form. So, awaiting the bone marrow report is crucial as it will guide further treatment decisions. Regarding bone marrow aspiration, it can be performed in either a prone or semiprone position based on the doctor's expertise.

I hope your concerns are addressed.

Thank you.