Dear DHINSB: Breast cancer can develop anywhere there is breast tissue. A mammogram is an appropriate first step. Standard xrays do not differentiate fluid as well as some other tests. Depending on the mammogram results, an ultrasound or biopsy may be the next step.
male breast cancer can form anywhere in the breast region. Mammogram won't tell more than what is known: there's a lump (or lumps) there. Statistically it's most likely innocent, but since cancer needs to be ruled out, it either needs surgical biopsy (or removal) or extremely close followup for awhile, no matter what the mammogram shows.