title: Suspected phenobarbital-induced pseudolymphoma in a cat.
abstract: METHODS
  A 4.5-year-old spayed female domestic shorthair cat was evaluated because of a generalized seizure disorder that developed after an anesthesia-related hypoxic event.
  
  
  RESULTS
  Following administration of phenobarbital, the seizures stopped but the cat developed severe generalized lymphadenopathy. Results of a CBC and serum biochemical analysis were unremarkable. Cytologic examination of the lymph nodes revealed a reactive lymphocyte population. Differential diagnoses included neoplasia and infection, but results of related diagnostic tests were all negative.
  
  
  RESULTS
  Treatment was changed from phenobarbital to levetiracetam. Ten days following discontinuation of phenobarbital, the lymph node enlargement resolved, and the cat remained free of seizures with levetiracetam as treatment.
  
  
  CONCLUSIONS
  Pseudolymphoma and anticonvulsant hypersensitivity syndrome are recognized potential sequelae to anticonvulsant administration in humans. However, a pseudolymphoma-like reaction to anticonvulsants in veterinary species has not previously been reported. This case highlighted a potentially serious yet reversible sequela to phenobarbital treatment that may have been mistaken for more severe illness such as neoplasia.
authors.affiliation: Medvet Center for Pets, 300 E Wilson Bridge Rd, Worthington, OH 43085, USA. megvet@earthlink.net
authors.forename: Meg J
authors.initials: MJ
authors.lastname: Baho
authors.forename: Roger
authors.initials: R
authors.lastname: Hostutler
authors.forename: William
authors.initials: W
authors.lastname: Fenner
authors.forename: Stephanie
authors.initials: S
authors.lastname: Corn
mesh_terms: D000818:Animals; D000927:Anticonvulsants / Q000009:adverse effects* / Q000627:therapeutic use; D002371:Cat Diseases / Q000139:chemically induced*; D002415:Cats; D004827:Epilepsy / Q000188:drug therapy / Q000662:veterinary*; D005260:Female; D000077287:Levetiracetam; D010634:Phenobarbital / Q000009:adverse effects* / Q000627:therapeutic use; D010889:Piracetam / Q000031:analogs & derivatives / Q000627:therapeutic use; D019310:Pseudolymphoma / Q000139:chemically induced / Q000662:veterinary*
chemical_list: D000927:Anticonvulsants; D000077287:Levetiracetam; D010634:Phenobarbital; D010889:Piracetam