title: A case of good syndrome presumed secondary to metastatic pancreatic thymoma in a patient presenting with a myasthenic crisis postthymectomy.
abstract: BACKGROUND
  Myasthenia gravis (MG) is an autoimmune disorder characterized by autoantibodies against the postsynaptic nicotinic acetylcholine receptors, muscle-specific tyrosine kinase, low-density lipoprotein receptor-related protein 4, and agrin. The incidence of thymoma in MG is reported as ∼10%-15%. The incidence of extrathoracic metastatic thymoma is exceedingly rare and may present years after resection. Associations between thymoma and immunodeficiency have also been described, including Good syndrome.
  
  
  RESULTS
  We describe the clinical course, investigations, and treatments performed in a patient presenting with a myasthenic crisis in the setting of acetylcholine receptor antibody-positive generalized MG 10 years postthymectomy. Computed tomography imaging revealed 2 pancreatic lesions, but no residual thoracic thymoma. Biopsy confirmed metastatic pancreatic thymoma, which was successfully resected. His course was further complicated by cytomegalovirus retinitis with a depressed CD4 count and perniosis.
  
  
  CONCLUSIONS
  This presentation was felt to be consistent with Good immunodeficiency syndrome.
authors.affiliation: *Division of Neurology, The University of British Columbia, Vancouver, British Columbia, Canada; and †Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Kristin L
authors.initials: KL
authors.lastname: Jack
authors.forename: Matt
authors.initials: M
authors.lastname: Kula
authors.forename: Julia D
authors.initials: JD
authors.lastname: Flint
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Mezei
mesh_terms: D001323:Autoantibodies / Q000097:blood; D002647:Chilblains / Q000175:diagnosis / Q000209:etiology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000175:diagnosis / Q000209:etiology* / Q000276:immunology / Q000503:physiopathology; D010179:Pancreas / Q000473:pathology*; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology*; D011950:Receptors, Cholinergic / Q000276:immunology; D013934:Thymectomy / Q000009:adverse effects*; D013945:Thymoma / Q000175:diagnosis* / Q000601:surgery; D013953:Thymus Neoplasms / Q000175:diagnosis / Q000276:immunology / Q000601:surgery*; D015898:Tomography Scanners, X-Ray Computed
chemical_list: D001323:Autoantibodies; D011950:Receptors, Cholinergic