Paraneoplastic diseases of peripheral and central nervous systems are rare manifestations of malignancies. Here we report a rare case of 51 year old male who presented with symmetrical progressive sensory and motor deficit over the course of one year. His past medical history included a malignant melanoma excised 5 years ago from the skin of interscapular region.
His nerve conduction studies showed evidence of severe, symmetrical, predominantly sensory, axonal peripheral neuropathy. He under-went CT chest-abdomen-pelvis which showed large right axillary lymph nodes. Axillary Lymph node biopsy contained metastatic melanoma cells positive with MelanA and HMB 45. Analysis of the BRAF gene from biopsy sample cells revealed the presence of a mutation within codon 600 of the BRAF gene. All further investigations did not show evidence of any other type of tumour.
Paraneoplastic syndromes can affect the motor, sensory and autonomic nervous systems and are associated with lung cancer, especially small-cell lung cancer, lymphoma and gynecological tumors. To our knowledge our case is the first report of paraneoplastic polyneuropathy secondary to malignant melanoma.
The presence of paraneoplastic neuropathy should be considered in all patients with malignancy and can happen at any point in the disease prior or after induction of any treatment. We report rare case of malignant melanoma presenting with paraneoplastic polyneuropathy.