title: Proteomics for the diagnosis of thyroid lesions: preliminary report.
abstract: OBJECTIVE
  Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) is a unique proteomic technology that explores the spatial distribution of biomolecules directly in situ, thus integrating molecular and morphological information. The possibility of correlating distribution maps of multiple analyses with cytological features makes it an ideal research tool for discovering new diagnostic markers. A previous study showed that MALDI-IMS could help discrimination between different types of thyroid lesions, especially papillary thyroid carcinoma (PTC); the present feasibility study on ex vivo fine needle aspiration (FNA) smears describes its potential in detecting new proteomic targets of other thyroid lesions (follicular lesions, medullary carcinoma).
  
  
  METHODS
  MALDI-IMS was conducted on ex vivo FNAs obtained from surgical specimens and corresponding in vivo samples. Differences between proteomic profiles of different thyroid lesions were compared.
  
  
  RESULTS
  Comparing the protein profiles of hyperplastic nodules obtained from three different patients with each other, and with a new PTC, showed a high degree of concordance, indicating good reproducibility of the IMS technology on cytological samples, suggesting its potential as a tool for biomarker discovery. Furthermore, comparison of the average proteomic profiles of hyperplastic nodules with a Hürthle cell adenoma revealed significant differences, underlying the capability of MALDI-IMS to distinguish between different thyroid lesions. Finally, the proteomic profile of medullary thyroid carcinoma was also characterized.
  
  
  CONCLUSIONS
  Our results confirmed the possible role of MALDI-IMS in the search for diagnostic targets of PTC and follicular lesions, which could be applied in larger trials aimed at the identification of proteins, convertible to cost-effective diagnostic tools such as immunohistochemistry. These tests could be used to analyse in vivo cytological smears, improving the preoperative diagnosis of indeterminate thyroid nodules.
authors.affiliation: Department of Pathology, San Gerardo Hospital, University Milan Bicocca, Monza, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Pagni
authors.affiliation: Department of Health Sciences, Proteomics, University Milan Bicocca, Milan, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Mainini
authors.affiliation: Department of Surgery, San Gerardo Hospital, Monza, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Garancini
authors.affiliation: Department of Pathology, San Gerardo Hospital, University Milan Bicocca, Monza, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Bono
authors.affiliation: Department of Pathology, San Gerardo Hospital, University Milan Bicocca, Monza, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Vanzati
authors.affiliation: Department of Surgery, San Gerardo Hospital, Monza, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Giardini
authors.affiliation: Department of Surgery, San Gerardo Hospital, Monza, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Scardilli
authors.affiliation: Department of Surgery, San Gerardo Hospital, Monza, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Goffredo
authors.affiliation: Department of Health Sciences, Proteomics, University Milan Bicocca, Milan, Italy.
authors.forename: A J
authors.initials: AJ
authors.lastname: Smith
authors.affiliation: Department of Health Sciences, Proteomics, University Milan Bicocca, Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Galli
authors.affiliation: Department of Health Sciences, Proteomics, University Milan Bicocca, Milan, Italy.
authors.forename: G
authors.initials: G
authors.lastname: De Sio
authors.affiliation: Department of Health Sciences, Proteomics, University Milan Bicocca, Milan, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Magni
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D044963:Biopsy, Fine-Needle / Q000379:methods; D002277:Carcinoma / Q000378:metabolism / Q000473:pathology; D018276:Carcinoma, Medullary / Q000378:metabolism / Q000473:pathology; D018278:Carcinoma, Neuroendocrine / Q000378:metabolism / Q000473:pathology; D002291:Carcinoma, Papillary; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D040901:Proteomics / Q000379:methods; D000077273:Thyroid Cancer, Papillary; D013961:Thyroid Gland / Q000378:metabolism* / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000378:metabolism* / Q000473:pathology
chemical_list: D015415:Biomarkers
keywords: MALDI-IMS; thyroid follicular lesions; Matrix-assisted laser desorption/ionization; fine needle aspiration cytology; imaging mass spectrometry; thyroid carcinoma; proteomics