Five months ago, my annual mammogram and an ultrasound showed a fibroadenoma in my right breast. I went to a surgeon, and he confirmed the diagnosis and told me to have another mammogram and ultrasound in six months. Meanwhile I'm a nervous wreck, even though I've been told this is benign. How common are these growths in women my age (42)? Does this increase my chances of getting breast cancer? Am I likely to get more of them? I've been told that I won't be able to feel this growth on self-exams.

--A.T.

Fibroadenomas are the most common solid breast masses. They are benign and are most often found in younger women (less than 25 years old). They are more common in African-Americans than in Caucasians. On mammograms and ultrasound, they appear smooth, with sharp, distinct margins. Most fibroadenomas get smaller with time; slightly more than one-third will get larger. Fibroadenomas do not increase the risk of breast cancer.

Because most masses in young women are benign, watchful waiting is acceptable. In older women, biopsy is often recommended. In any event, if you are uncomfortable with observation, you should discuss surgical removal of the lump with a surgeon. Following with mammography in six months is a recommendation, not the only choice. Most likely, the mass really is a benign fibroadenoma, but if you are going to be at your wit's end for the next six months, you might want to consider having the lump removed.