What happened, in summary

Goodie16 found a lump in the left breast in April 2014. Mammography did not show the lump, but ultrasound and biopsy confirmed invasive ductal carcinoma. They underwent mastectomy, and the lymph nodes were clear. The cancer was staged as IA, the Oncotype DX recurrence score was 12, and chemotherapy and breast radiation were not recommended. They began tamoxifen.

A brain MRI performed during the initial workup had shown a small abnormality in the right temporal lobe. Four specialists believed it was a benign cavernoma. In February 2015, Goodie16 had a grand mal seizure after the lesion bled. During a craniotomy three days later, the lesion was removed and pathology showed that it was a breast-cancer metastasis measuring less than one centimeter. They then received Gamma Knife radiation to the tumor bed.

Tamoxifen was stopped in November 2015 because of side effects. They later started Lupron injections and planned to add Arimidex. The September 2015 PET scan showed no evidence of disease, and the March 2016 brain MRI was clear. The experience shows how an apparently early-stage breast cancer diagnosis changed after a brain lesion originally thought to be benign was correctly identified.