Anti-Yo antibody–mediated paraneoplastic cerebellar degeneration associated with cognitive affective syndrome in a patient with breast cancer: a case report and literature review

摘要

Breast cancer is the most common cancer in women, with 15%–25% of those tumours overexpressing the human epidermal growth factor receptor 2 (her2), which is associated with more aggressive disease. On rare occasions, patients present with a paraneoplastic syndrome months to years before their cancer diagnosis. Paraneoplastic cerebellar degeneration (pcd) is associated with fewer than 1% of cancers and is strongly associated with breast and gynecologic malignancies. Anti-Yo antibody is the antibody most frequently identified with the syndrome, and it is associated with a very poor prognosis. Recent studies have implicated a relationship between overexpression of her2 and anti-Yo–mediated pcd. Current pcd treatments include tumour removal, chemotherapy, targeted therapy, and immune-suppressive treatments. Outcomes of pcd are typically poor, and no guidelines for treatment currently exist. Early recognition followed by rapid initiation of treatment remains the cornerstone of therapy.Here, we present a case of anti-Yo-antibody pcd secondary to estrogen and progesterone receptor–negative, her2-positive breast cancer. Despite treatment with mastectomy, chemotherapy, and her2-targeted therapy, no significant neurologic improvement was achieved, and cerebellar cognitive affective syndrome subsequently developed.