I would recommend that the mother and her doctor explore other ways of
diagnosing this lump.  I realize the issue here is if it is a "cold"
nodule (doesn't pick up isotope), there is more concern that it might
be cancer, but surely a biopsy might be a way to deal with this.  In
any case, after a scan it is sometimes necessary to do a biopsy
anyhow, depending on what they find.  For the breastfeeding mother and
baby, especially in this circumstance, wouldn't it be better to skip
the scan and do something else?

Jack Newman, MD, FRCPC