[Paraneoplastic chorea and behavioral disorders in a patient with anti-CV2/CRMP5 antibodies and two different tumors]. / Chorée paranéoplasique et troubles du comportement chez un patient présentant des anticorps anti-CV2/CRMP5 et deux cancers différents.

INTRODUCTION: Paraneoplastic movement disorders are rare. Reported cases frequently describe association with anti-CV2/CRMP5 antibodies. CASE REPORT: We report a case of an 80-year-old man who developed sensorial neuronopathy, following by movement disorders mimicking chorea and obsessive-compulsive and behavioral disorders. These manifestations were first considered to be associated with a prostatic adenocarcinoma but PET and surgical biopsy revealed a mediastinal small cell lung carcinoma classically associated with anti-CV2/CRMP5 antibodies. CONCLUSION: This case demonstrates that in a context of paraneoplastic neurological syndrome, search for a classically associated cancer is necessary in order to institute adapted treatment early, even if another tumor is obvious.