title: Proteomic approach used in the diagnosis of Riedel's thyroiditis: a case report.
abstract: BACKGROUND
  Riedel's thyroiditis, a rare thyroid disease, can be difficult to diagnose prior to surgical removal and can be confused with malignancy both clinically and cytologically.
  
  
  METHODS
  We report the case of a 72-year-old Caucasian woman who presented with a goiter, which showed a rapid increase in size at ultrasound check, suggesting malignancy. Because of inconclusive cytology, a total thyroidectomy was performed. Fine-needle aspiration of the removed thyroid was processed by two-dimensional electrophoresis, and the proteome was compared with both anaplastic cancer and control samples. Significant differentially expressed protein spots were identified by Western blot analysis by using specific antibodies.
  
  
  CONCLUSIONS
  The protein pattern of Riedel's fine-needle aspiration revealed a superimposition with that of the control samples. The comparison of the protein pattern of Riedel's thyroiditis fine-needle aspiration with that of anaplastic cancer showed evidence of a different expression of ferritin heavy chains, ferritin light chains, and haptoglobins, as previously reported in thyroid cancers. Therefore, we performed Western blot analysis of these proteins and validated that their expression levels were low or absent in Riedel's thyroiditis and control samples despite the high concentrations present in fine-needle aspiration anaplastic samples. The concurrent absent or low expression levels of haptoglobin, ferritin light chain, and ferritin heavy chain in Riedel's thyroiditis fine-needle aspiration samples strongly indicate the benign nature of the thyroid lesion. These results suggest the potential applicability of fine-needle aspiration proteome analysis for Riedel's thyroiditis diagnosis.
authors.affiliation: Department of Psychiatry, Neurobiology, Pharmacology and Biotechnology, Via Bonanno 6, University of Pisa, 56126 Pisa, Italy. lucas@farm.unipi.it.
authors.forename: Pietro
authors.initials: P
authors.lastname: Iacconi
authors.forename: Laura
authors.initials: L
authors.lastname: Giusti
authors.forename: Ylenia
authors.initials: Y
authors.lastname: Da Valle
authors.forename: Federica
authors.initials: F
authors.lastname: Ciregia
authors.forename: Gino
authors.initials: G
authors.lastname: Giannaccini
authors.forename: Liborio
authors.initials: L
authors.lastname: Torregrossa
authors.forename: Agnese
authors.initials: A
authors.lastname: Proietti
authors.forename: Gianluca
authors.initials: G
authors.lastname: Donatini
authors.forename: Salvatore
authors.initials: S
authors.lastname: Mazzeo
authors.forename: Fulvio
authors.initials: F
authors.lastname: Basolo
authors.forename: Antonio
authors.initials: A
authors.lastname: Lucacchini