A Case of Myelitis due to Paraneoplastic Neurological Syndrome after Mastectomy

Abstract

A 54-year-old woman with right breast cancer underwent right mastectomy with axillary lymph node dissection (level II dissection). She was diagnosed with invasive ductal carcinoma, solid type (ER (-), PgR (-), HER2 (0), MIB-1 labeling index > 90%, and T2N0M0, stage IIA). Her symptoms included vomiting and numbness/weakness in her bilateral upper extremity within 4 weeks after surgery. She was referred to the Department of Neurology to check for non-surgery-related causes. She was positive for anti-Zic4 antibody and was diagnosed with myelitis due to paraneoplastic neurologic syndrome. On admission, she was initiated on steroid pulse therapy. Her neurological symptoms gradually improved, and she was discharged approximately 1 month later. Her prednisolone dosage was gradually tapered until 10 months later. She underwent adjuvant chemotherapy 5 months after mastectomy, and no recurrence or metastasis was observed 1 year later. Paraneoplastic neurological syndrome requires prompt diagnosis and treatment. In patients showing unexplained postoperative neurological symptoms, the possibility of paraneoplastic neurological syndrome should be considered.