Well, this issue is very interesting as gray zone between classification of CML phases. Some issues are very old and belong to CML past but they still have some value. According to WHO 2016 myeloid neoplasm classification large foci of blasts are considered as advanced disease (at least acceleration) but this criteria is weaken by last ELN criteria for chronic phase. Unfortunately percentage of blasts and basophils in peripheral blood and bone marrow are lacking in description. It would be nice also to have data about karyotype if performed, to be sure that there is no additional aberrations. If percentage of blast within marrow and/or PB is less than 10% (ELN says even 20% but I do not like this high value for safety reasons) and no additional karyotype aberrations this biopsy finding definitely is irrelevant in case of imatinib treatment and I will use standard dose imatinib frontline. In the opposite case (high percentage of blast or basophils, or additional karyotype abnormalities), than I will consider it very relevant and the patients would be classified as at least accelerated phase and I will use imatinib 600mg (especially if large spleen is present).
Best regards
Andrija Bogdanovic (ebogdano@eunet.rs), Belgrade

ORIGINAL CASE:
What would the phase of a patient diagnosed with CML if the bone marrow biopsy shows FOCI OF BLASTS and if the other parameters meet the chronic phase criteria?

Respected sir/madam,

What would the phase of a patient diagnosed with CML if the bone marrow biopsy shows FOCI OF BLASTS and if the other parameters meet the chronic phase criteria.

Thank you.