Ilene: It sounds as though you are right on top of things, but I would make a few more comments. First, breast tissue, including lactiferous ducts, extend up under the armpit. This is the reason that Breast Self Exam should include an exam under the arm pit. Second, I would check out what type of bra she is wearing. Underwires can cause the underarm ducts to plug. If this is truly a plugged duct, uncomplicated by infection, then going braless, deep massage--including breast compression during nursing, using gravity while feeding and changing feeding positions freqently should help. Of course there's always cabbage leaves too. If this is not a ductal issue and really is a lymph node, I would see if mom shaves her arm pits. This practice can cause minor infections which cause lymph nodes to flare up (I've personally experienced this). If that isn't the case, then check out her other lymph nodes on that side of the body, especially in the neck region. If the lump just appeared over night, the likelihood of cancer is miniscule (but not zero). In any case, this mom can increase her vitamin C consumption and start echinacea. If plugged ducts become a repeated problem, then B-Complex, thyme, and lecithin can also be added. I hope this helps. : )Chris Hafner-Eaton, PhD, MPH, CHES, IBCLC email: [log in to unmask] : ) : )HSR & Health Educational Consultant voice/fax: 541 753 7340 : ) : )LLLLLLLLLLLLL**CHANGE THE WORLD, NURTURE A CHILD!**LLLLLLLLLLLLLLLLLL : )