Post-treatment swelling

My wife had neoadjuvant chemo starting a year ago, a lumpectomy in December, more chemo starting around Christmas and a full course of radiation that ended in May.  Recently the breast that had the cancer has become swolen. She occassionally gets sharp pains near the surgical scars (she also had all of her lymph node removed, and later, a re-excision). The texture of the breast if firm when compared to her other breast and the surface of the skin looks and feels different.  Is this something to be worried about? Could it just be a buildup of lymph fluid?
Thanks,
Neal

[CCF-RN,MSN-rf]

Dear Neal:  This could be as simple as lymphedema that has settled in the breast but it is important to have this examined to be sure that it does not represent a recurrence.

[surgeon]

a radiated breast very often feels firmer than the other, and the skin can be thicker and darker. It's not common for lymph to build up in the breast; lymphedema most typically occurs in the arm. What you describe sounds as if it's within the spectrum of post radiation result.