title: Laser capture microdissection is a valuable tool in the preoperative molecular screening of follicular lesions of the thyroid: an institutional experience.
abstract: OBJECTIVE
  The application of molecular tests to thyroid fine needle aspiration (FNA) has been shown to be a valuable tool to better refine the pre-operative malignant risk of patients with indeterminate cytology results. In this study, we investigated the feasibility of using the laser capture microdissection (LCM) technique to obtain DNA and RNA for molecular tests in routine thyroid FNA smears.
  
  
  METHODS
  Nine coupled FNA and histological retrospective cases and 31 prospective FNA cases with a follicular neoplasm/suspicious for a follicular neoplasm (FN/SFN) diagnosis were included in this study. Both cytological and histological specimens were investigated by direct sequencing and reverse transcription-polymerase chain reaction (RT-PCR) for BRAF and RAS mutations and for PAX8/PPARG and RET/PTC rearrangements, respectively.
  
  
  RESULTS
  LCM yielded good DNA and RNA quality in all cases (100%) in both series, irrespective of the staining used (Giemsa, Papanicolaou, immunostain for thyroglobulin) and the cytology technique (conventional or liquid-based preparations). Total mutations found in the FNA and in the corresponding histological specimen in both series were: one PAX8/PPARG rearrangement in a follicular carcinoma (FC), four NRAS mutations [in two FCs, one papillary carcinoma and one follicular adenoma (FA)] and one HRAS mutation in one FA. The sensitivity was 67% and the specificity was 91%.
  
  
  CONCLUSIONS
  LCM is a valuable tool to obtain good quality DNA and RNA for molecular tests in cytological material from thyroid FNA, and can be a useful option in the management of patients with an FN/SFN FNA diagnosis.
authors.affiliation: Institute of Pathology, Locarno, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Bongiovanni
authors.affiliation: Institute of Pathology, Locarno, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Molinari
authors.affiliation: Division of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Eszlinger
authors.affiliation: Division of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Paschke
authors.affiliation: Institute of Pathology, Locarno, Switzerland.
authors.forename: J
authors.initials: J
authors.lastname: Barizzi
authors.affiliation: Institute of Pathology, Locarno, Switzerland.
authors.forename: E
authors.initials: E
authors.lastname: Merlo
authors.affiliation: Department of Nuclear Medicine and Thyroid Centre, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Giovanella
authors.affiliation: Department of Surgery, Ente Ospedaliero Cantonale, Mendrisio, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Fasolini
authors.affiliation: Private Practice Endocrinologist, Lugano, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Cattaneo
authors.affiliation: Private Practice Endocrinologist, Locarno, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Ramelli
authors.affiliation: Institute of Pathology, Locarno, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Mazzucchelli
authors.affiliation: Institute of Pathology, Locarno, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Frattini
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology*; D000236:Adenoma / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology*; D044963:Biopsy, Fine-Needle / Q000379:methods; D003581:Cytodiagnosis / Q000379:methods; D004247:DNA / Q000235:genetics; D005260:Female; D006801:Humans; D061346:Laser Capture Microdissection / Q000379:methods; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods; D009154:Mutation / Q000235:genetics; D000072636:PAX8 Transcription Factor; D047495:PPAR gamma / Q000235:genetics; D051761:Paired Box Transcription Factors / Q000235:genetics; D011446:Prospective Studies; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D051096:Proto-Oncogene Proteins c-ret / Q000235:genetics; D012313:RNA / Q000235:genetics; D012189:Retrospective Studies; D013961:Thyroid Gland / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology*; D018631:ras Proteins / Q000235:genetics
chemical_list: D000072636:PAX8 Transcription Factor; C083325:PAX8 protein, human; D047495:PPAR gamma; D051761:Paired Box Transcription Factors; D012313:RNA; D004247:DNA; D051096:Proto-Oncogene Proteins c-ret; C099282:RET protein, human; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D018631:ras Proteins
keywords: BRAF; PAX8/PPARG; RAS; RET/PTC; fine needle aspiration; laser-capture microdissection; molecular analysis; thyroid follicular lesions