Thanks for your query. CHEMOTHERAPY
can be TERATOGEN for the developing fetus, as it is in remission stage, hence it is advisable not to take any ALL medications. The lump could be developing breast glands, which gets hypertrophied during pregnancy
. Its better you get her evaluated from hemato oncologist
I hope this information has been both informative and helpful for you. In case of any doubt, I will be available for follow ups.
Wish you good health.