What happened, in summary

A 50-year-old woman developed progressive neurological symptoms before her breast cancer was diagnosed. She had been unsteady while walking for 4 months, had tremors in both hands for 4 months, slurred speech for 2 months and drooling for 1 month. Examination showed severe coordination problems, bilateral facial weakness and a Karnofsky performance score of 50. She also had a painless 5 × 5 cm lump in the right breast and a 2 × 2 cm right axillary lymph node.

Further evaluation identified Stage II invasive right breast cancer alongside paraneoplastic cerebellar degeneration. She underwent a right modified radical mastectomy. Pathology showed infiltrating ductal carcinoma with clear surgical margins, extensive lymphovascular invasion and cancer in 8 of 18 lymph nodes. Her postoperative recovery was uncomplicated.

She was referred to medical oncology to consider adjuvant chemotherapy and radiation. Because her functional status remained poor, with a Karnofsky score of 50, both treatments were deferred and she received symptomatic care instead. No specific treatment was given for the neurological condition.

She attended surgical follow-up for 2 months, after which her son provided monthly updates by telephone. At 6 months after surgery, the neurological symptoms had not improved, but they had also not deteriorated further. She continued to need help with self-care, and the neurological disability remained the main problem affecting her daily life.