P11.71.B Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) in a patient with blastic plasmacytoid dendritic cell neoplasm: a rare neurologic manifestation in a rare disease

Abstract Background Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare aggressive myeloid hematological malignancy. Skin lesions, bone marrow, lymph nodes or visceral organs can be involved. 30% of patients will have infiltration to the nervous system,occult asymptomatic frequent. Immunophenotype express CD4, CD56, and CD123, flow cytometry essential. Material Methods 70-yo Hispanic male with 1-month history multiple violaceous cutaneous nodules adenopathies.Neurological complaints included diplopia, hypoesthesia in left face, dysphagia, gait difficulties, generalized weakness distal hypoesthesia. Examination revealed cranial neuropathy (bilateral VI VII nerve palsies, V3 VIII palsies IX, X involvement), global areflexia, length-dependent weakness, ataxic cerebellar syndrome. An inguinal ganglionar biopsy retrieved cells positive for TCL1, CD68 whereas CD3, CD20, CD7, CD8, CD30 myeloperoxidase were negative. PET/CT showed supra infradiaphragmatic adenopathies, bilateral pleural, pericardial abdominal implants. Bone marrow was Brain MRI contrast enhancement folia roots nerves clinically Multiple CSFs demonstrated high protein count (281- 310mg/dl), normal glucose count; CSF cytology reported no blastic (negative CD56 CD123), onconeuronal antibodies Nerve conduction studies fulfilled definite electrodiagnostic EFNS criteria CIDP. Sural inflammatory demyelination without infiltration. Systemic chemotherapy (Cyclophosphamide/Vincristine) intrathecal cytarbine/methotrexate administered. Results Favorable initial, but brief response noticed gait. He had neurological relapse impossibility. Neuraxis brain new lumbosacral roots. severe worsening The complete response. Five days methylprednisolone (1gr IV) followed by oral prednisone prescribed (50 mg qd). However, two weeks later he suffered clinical respiratory failure. IVIg started (.4g/kg/day 5 days) improvement; palliative care decision consented. Conclusion We report case an adult palsy, syndrome refractory rapidly progressive asymmetric polyneuropathy BPDCN. CIDP absence attempts demonstrate system led us consider this as paraneoplastic phenomenon treatment. To our knowledge has been disease