title: Multicentric Castleman's disease with voltage-gated potassium channel antibody-positive limbic encephalitis: a case report.
abstract: BACKGROUND
  Castleman's disease is a rare lymphoproliferative disorder which occurs in localized and multicentric forms and can mimic lymphoma. Despite its well-known association with certain autoimmune diseases, including paraneoplastic pemphigus and myasthenia gravis, Castleman's disease has not previously been associated with limbic encephalitis.
  
  
  METHODS
  We report the case of a 47-year old Caucasian man who presented with subacute onset of constitutional symptoms, diffuse lymphadenopathy, and stereotyped spells involving olfactory aura, nausea, disorientation, and unresponsiveness. He was found to have focal dyscognitive seizures of temporal lobe origin, cerebrospinal fluid with lymphocytic pleocytosis, hyponatremia, and serum positive for voltage-gated potassium channel antibodies, consistent with limbic encephalitis. An extensive infectious workup was unrevealing, but lymph node biopsy revealed multicentric Castleman's disease. His symptoms improved with antiepileptic drugs and immunotherapy.
  
  
  CONCLUSIONS
  This case highlights the clinical diversity of voltage-gated potassium channel autoimmunity and expands the association of Castleman's disease and autoimmune syndromes to include limbic encephalitis. Clinicians should be aware that paraneoplastic disorders of the central nervous system can be related to underlying hematologic disorders such as Castleman's disease.
authors: Department of Neurology, University of California, San Francisco, 400 Parnassus Ave, 8th Floor, San Francisco, CA, 94143, USA. vikram.rao@ucsf.edu.
authors: Vikram R
authors: VR
authors: Rao
authors: Neurology Service, Department of Veteran Affairs, Palo Alto Health Care System, 3801 Miranda Avenue, Palo Alto, CA, 94304, USA. leland.lim@va.gov.|Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, 94305, USA. leland.lim@va.gov.
authors: Leland E
authors: LE
authors: Lim
authors: Pathology and Laboratory Medicine Service, Department of Veteran Affairs, Palo Alto Health Care System (113), 3801 Miranda Avenue, Palo Alto, CA, 94304, USA. dean.fong@va.gov.
authors: Dean
authors: D
authors: Fong
authors: Epilepsy Center of Excellence, San Francisco Veteran Affairs Medical Center, 4150 Clement Street, Box 127E, San Francisco, CA, 94121, USA. nina.garga@va.gov.
authors: Nina I
authors: NI
authors: Garga
authors: Epilepsy Center of Excellence, San Francisco Veteran Affairs Medical Center, 4150 Clement Street, Box 127E, San Francisco, CA, 94121, USA. karen.parko@va.gov.
authors: Karen L
authors: KL
authors: Parko
mesh_terms: D000906:Antibodies / Q000097:blood*; D005871:Castleman Disease / Q000175:diagnosis*; D006801:Humans; D020363:Limbic Encephalitis / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D024642:Potassium Channels, Voltage-Gated / Q000276:immunology*; D012640:Seizures / Q000209:etiology
chemical_list: D000906:Antibodies; D024642:Potassium Channels, Voltage-Gated
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