Sweat gland breast cancer underarm

Had tumor taken out underarm sweat gland 2 years ago .Mayo said breast tissue origin but not any thing else found in body so far. Had many glands removed . Put on tomoxifen . Now it came back in the same place 2 years later . I don't see any follow ups from people that posted about this in the two years that have past . Is anyone else dealing w this ?Hidradenocarcinoma .