title: Differentiating benign from malignant thyroid nodules using micro ribonucleic acid amplification in residual cells obtained by fine needle aspiration biopsy.
abstract: BACKGROUND
  Fine needle aspiration biopsy (FNAB) is the most commonly used diagnostic tool to differentiate benign from malignant thyroid nodules. Nevertheless, some FNAB cytology results are not definite. In such cases diagnostic thyroid lobectomy is performed with malignancy rate on final histopathology ranging at 15%-75%. The aim of this study was to improve on the accuracy of FNAB-based cytology by amplification of microRNAs (micro ribonucleic acids [miRs]) from the residual cells left in the FNAB needle after submission for cytology.
  
  
  METHODS
  Residual cells were collected from the needle cup after FNAB cytology of 77 consecutive patients with thyroid nodules. miR-enriched RNA was extracted for all patients with cytology showing either follicular lesion or suspicion for malignancy (n=11). The expression of miR-21, -31, -146b, -187, -221, and -222 was determined using real-time polymerase chain reaction. Results were compared with final surgical histopathology.
  
  
  RESULTS
  RNA was successfully extracted from all FNAB specimens. Five patients had FNAB cytology suspicious for malignancy. The miR panel was positive in all five (100%). Six patients had follicular lesions on FNAB. The miR panel was positive in three of four patients (75%) with confirmed malignancy and was negative in two of two (0%) patients with benign pathology results. This corresponded to a specificity of 100%, sensitivity of 88%, and accuracy of 90%.
  
  
  CONCLUSIONS
  RNA extraction from FNAB residual cells is feasible, and a miR panel amplified from the extracted RNA seems like a promising diagnostic tool in this limited number of patients.
authors.affiliation: The Surgical Oncology Laboratory, Department of Surgery, Hadassah-Hebrew University Medical Center, Mount Scopus, Jerusalem, Israel.
authors.forename: Haggi
authors.initials: H
authors.lastname: Mazeh
authors.forename: Yair
authors.initials: Y
authors.lastname: Levy
authors.forename: Ido
authors.initials: I
authors.lastname: Mizrahi
authors.forename: Liat
authors.initials: L
authors.lastname: Appelbaum
authors.forename: Nadia
authors.initials: N
authors.lastname: Ilyayev
authors.forename: David
authors.initials: D
authors.lastname: Halle
authors.forename: Herbert R
authors.initials: HR
authors.lastname: Freund
authors.forename: Aviram
authors.initials: A
authors.lastname: Nissan
mesh_terms: D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle / Q000379:methods*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000032:analysis*; D008875:Middle Aged; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D013961:Thyroid Gland / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D016606:Thyroid Nodule / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology
chemical_list: D035683:MicroRNAs