Demyelinating neuropathy with anti-CRMP5 antibodies predating diagnosis of breast carcinoma: favorable outcome after cancer therapy

Abstract

Introduction: Breast cancer is exceptionally associated with anti-collapsin response mediator protein 5 (anti-CRMP5) antibody or demyelinating neuropathy. This paraneoplastic antibody is itself not associated with demyelinating neuropathy.

Methods: Herein we describe a patient with a predominantly sensory ataxic demyelinating neuropathy associated with an IgG-kappa monoclonal gammopathy of uncertain significance (MGUS). Further investigations led to identification of anti-CRMP5 antibodies. An initial search for a malignancy proved negative. No immunomodulatory therapy was administered.

Results: The patient developed breast carcinoma 2 years after the initial neurological symptoms, which was effectively treated by surgery, chemotherapy, hormone therapy, and radiotherapy. At neurological follow-up, 16 months after cancer treatment, she remained in remission and had made substantial neurological recovery. Electrophysiology showed significant amelioration, and serum anti-CRMP5 antibodies were undetectable. MGUS paraprotein level was unchanged.

Conclusion: This case widens the range of paraneoplastic manifestations of breast carcinoma to include anti-CRMP5 antibody-positive sensory ataxic demyelinating neuropathy, which, in this patient, improved after cancer treatment.