Agree with Bepe. If this is extramedullary disease, it should be considered like blast crisis. Would consider radiating the lesion and if otherwise responding to TKI, go to allografting in a young person

To answer this question I have to go back to the opinion of John Goldman (as well as of other experts); extra-medullary CML has to be considered a progression and transformation of CML similar to blast crisis, in particular if the patient was already in TKI therapy. Is this the case?
Yours, Beppe Saglio

We have a young male with muscle lesion which on biopsy is CML.
He is CML in CP on BM studies.
Cytogenetics: no other abnormalities other than PH chromosome

Is extramedullary CML (without any increase in blasts) be considered as blast crisis?

Regards
Saurabh