Cysts are quite common and often occur
with hormonal variation (including menstruation and
hormone replacement therapy). Of course, lumpy breast tissue can also swell as a result of hormonal variation. If you are concerned, you should see your doctor for evaluation and he/she can order an ultrasound, if appropriate. Also, just so you are aware, “natural” hormone replacement has the same risks of estrogen exposure as “clinical” HRT. Estrogen is estrogen, whether it is from soy or the lab.