What happened, in summary

A 52-year-old woman presented with a lump in her left breast. Biopsy showed grade 3 invasive ductal carcinoma that was ER-negative, PR-negative, and HER2 3+. She received 3 cycles of neoadjuvant cyclophosphamide, doxorubicin, and fluorouracil, followed by modified radical mastectomy. Postoperative treatment included locoregional radiation, 4 more chemotherapy cycles, and trastuzumab.

Two years later, she developed subtle speech and walking problems that progressed rapidly over 20 days until she needed a wheelchair. Examination showed severe loss of coordination. Anti-Yo antibody was positive. PET imaging also found a chest-wall nodule and lymph-node disease, while brain MRI showed no metastasis. Biopsies confirmed recurrent grade 3, ER-negative, PR-negative, HER2-positive breast cancer.

She received 5 days of methylprednisolone for paraneoplastic cerebellar degeneration. Intravenous immunoglobulin was advised but was unaffordable. The recurrent nodule was removed and the right axillary nodes were dissected, followed by 14 cycles of trastuzumab and paclitaxel. Her neurological disability continued to progress despite treatment.