title: Necessity for long-term follow-up of patients with head and neck paraganglioma and mutation in the succinate dehydrogenase genes: an index case report and literature review.
abstract: OBJECTIVE
  To describe a patient with hereditary head and neck paraganglioma (HNPGL) and to review the literature on these rare tumors.
  
  
  METHODS
  We review the English-language literature regarding SDH mutations, HNPGL, hereditary paraganglioma-pheochromocytoma syndrome, and the role of functional imaging in the follow-up of these tumors. We also describe the clinical findings, imaging results, and follow-up of a man who initially presented with HNPGL and subsequently developed metastatic pheochromocytoma 20 years later.
  
  
  RESULTS
  A 66-year-old man presented with a history of hypertension, palpitations, sweating, and elevated urinary norepinephrine. Iodine-123-metaiodobenzylguanidine (123I-MIBG) scan demonstrated a left suprarenal mass and multiple avid lesions in the abdomen, chest, and posterior cranial fossa. Histologic examination confirmed a metastatic pheochromocytoma, and molecular genetic testing revealed a mutation in the SDHD gene. The patient had had surgery 20 years earlier for HNPGL. Although most HNPGLs arise sporadically, susceptibility genes have been identified in approximately one-third of cases. Optimal follow-up remains controversial. We reiterate a need for long-term follow-up of patients with a mutation in an SDH gene. 123I-MIBG, highly specific for identifying ectopic neuroendocrine tissue, may have a role in long-term follow-up.
  
  
  CONCLUSIONS
  Although HNPGLs rarely metastasize, their malignant potential is difficult to predict. Routine surveillance for at-risk patients is recommended. Patients with a mutation in an SDH gene should therefore undergo regular surveillance.
authors.affiliation: Department of Nuclear Medicine, Sussex University Hospitals NHS Trust, Brighton, United Kingdom. karimsamji@gmail.com
authors.forename: Karim B
authors.initials: KB
authors.lastname: Samji
authors.forename: Anna L
authors.initials: AL
authors.lastname: Crown
authors.forename: Muriel S
authors.initials: MS
authors.lastname: Buxton-Thomas
authors.forename: Simon J B
authors.initials: SJ
authors.lastname: Aylwin
authors.forename: Klaus-Martin H
authors.initials: KM
authors.lastname: Schulte
authors.forename: Sabina
authors.initials: S
authors.lastname: Dizdarevic
mesh_terms: D000368:Aged; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000235:genetics*; D006801:Humans; D008297:Male; D009154:Mutation; D010235:Paraganglioma / Q000175:diagnosis* / Q000235:genetics*; D013385:Succinate Dehydrogenase / Q000235:genetics*
chemical_list: D013385:Succinate Dehydrogenase