title: Thyroid C-cell hyperplasia in an adolescent with neurofibromatosis type 1.
abstract: BACKGROUND
  Subjects with neurofibromatosis type 1 (NF1) show an increased risk of endocrine tumors, especially pheochromocytoma, whereas thyroid C-cell hyperplasia (CCH) and medullary thyroid carcinoma (MTC) are very rare events described only in adult patients.
  
  
  METHODS
  A case of CCH diagnosed in a 14-year-old girl affected with NF1 is reported. Calcitonin serum level after pentagastin was elevated (286 pg/ml). Genetic testing was performed in order to rule out mutations in the RET proto-oncogene.
  
  
  RESULTS
  No germline mutation previously reported in MEN2 was detected. Multifocal and bilateral CCH was demonstrated by immunohistochemistry.
  
  
  CONCLUSIONS
  It is suggested that in such a genetic background of high risk for malignancy, CCH could be considered as an extremely rare condition likely preceding MTC.
authors.affiliation: Department of Pediatrics, University 'La Sapienza', Rome, Italy. m.segni@mclink.it
authors.forename: M
authors.initials: M
authors.lastname: Segni
authors.forename: R
authors.initials: R
authors.lastname: Massa
authors.forename: V
authors.initials: V
authors.lastname: Bonifacio
authors.forename: F
authors.initials: F
authors.lastname: Tartaglia
authors.forename: I
authors.initials: I
authors.lastname: Pucarelli
authors.forename: A
authors.initials: A
authors.lastname: Marzullo
authors.forename: A M
authors.initials: AM
authors.lastname: Pasquino
mesh_terms: D002648:Child; D005260:Female; D006801:Humans; D006965:Hyperplasia; D007150:Immunohistochemistry; D009456:Neurofibromatosis 1 / Q000473:pathology*; D000090063:Proto-Oncogene Mas; D013961:Thyroid Gland / Q000473:pathology*