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
Authors: Garcilazo-Reyes Y , Zapata-Canto N , Cacho-Díaz B , Navarro-Fernández O , Espinoza-Zamora R , Bonilla-Navarrete A , Avilés-Salas A 
Published: September 2022

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 infiltration is frequent. Immunophenotype express CD4, CD56, and CD123, and flow cytometry is essential.

Material and Methods
70-yo Hispanic male with a 1-month history of multiple violaceous cutaneous nodules and adenopathies.Neurological complaints included diplopia, hypoesthesia in the left face, dysphagia, gait difficulties, and generalized weakness with distal hypoesthesia. Examination revealed multiple cranial neuropathy (bilateral VI and VII nerve palsies, left V3 and VIII palsies and IX, X involvement), global areflexia, length-dependent weakness, ataxic gait and cerebellar syndrome. An inguinal ganglionar biopsy retrieved cells positive for CD4, TCL1, CD68 and CD123, whereas CD3, CD20, CD7, CD8, CD30 and myeloperoxidase were negative. PET/CT showed multiple supra and infradiaphragmatic adenopathies, bilateral pleural, pericardial and abdominal implants. Bone marrow biopsy was negative. Brain MRI showed contrast enhancement in the cerebellar folia and in the roots of the cranial nerves clinically involved. Multiple CSFs demonstrated high protein count (281- 310mg/dl), normal glucose and cell count; CSF flow cytometry and cytology reported no blastic infiltration (negative CD4, CD56 and CD123), CSF onconeuronal antibodies were negative. Nerve conduction studies fulfilled definite electrodiagnostic EFNS criteria for CIDP. Sural nerve biopsy reported inflammatory demyelination without infiltration. Systemic chemotherapy (Cyclophosphamide/Vincristine) with intrathecal cytarbine/methotrexate was administered.

Results
Favorable initial, but brief response was noticed for the cranial nerves and gait. He had neurological relapse with gait impossibility. Neuraxis MRI showed no contrast enhancement in the brain but new contrast enhancement of lumbosacral roots. Nerve conduction studies reported severe worsening criteria of CIDP. The PET/CT demonstrated complete response. Five days of methylprednisolone (1gr IV) followed by oral prednisone were prescribed (50 mg qd). However, two weeks later he suffered clinical neurological worsening with respiratory failure. IVIg was started (.4g/kg/day for 5 days) with no improvement; palliative care decision was consented.

Conclusion
We report the case of an adult male with multiple cranial nerve palsy, cerebellar syndrome and refractory rapidly progressive asymmetric polyneuropathy with BPDCN. CIDP in the absence of multiple attempts to demonstrate nervous system infiltration led us to consider this as a paraneoplastic phenomenon refractory to treatment. To our knowledge no CIDP has been reported in this rare disease