title: [Incidence of malignant lesions in patients with clinically benign thyroid nodules: observational and prospective study in a cohort of 50 patients followed during two years].
abstract: BACKGROUND
  To study the frequency of malignant lesions in patients with clinically benign thyroid nodules and the value of the repetition of fine needle aspiration biopsy (FNAB).
  
  
  METHODS
  Observational and prospective 2-year study in a cohort of 50 patients with clinically benign thyroid nodules. Patients were initially submitted to clinical examination, ultrasound (US) and FNAB1 patients, followed by a second FNAB and US.
  
  
  RESULTS
  Palpation is not a good test for diagnosis and follow-up of thyroid nodules. On the other hand, the initial consideration that these patients should harbor benign lesions is a very useful parameter, since 47/50 patients (94%) did not present malignant lesions during the follow-up. FNAB1 and FNAB2 were concordant in 33/39 patients when FNAB1 was negative (85%); 11 patients were operated, 8 by suspicious FNAB and 3 due to nodule growth. We observed 2 patients with non-invasive papillary microcarcinoma and 1 patient with papillary carcinoma outside of the main nodules.
  
  
  CONCLUSIONS
  there was concordance between initial clinical benign diagnosis, FNAB and the follow-up. In one case there was a papillary carcinoma. In addition, ultrasonography should be considered for all patients with suspected thyroid nodules. Finally, we demonstrated that a second cytology usually confirms the result of the first cytology in benign thyroid nodules.
authors.affiliation: Departamento de MEdicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP.
authors.forename: Claudia A
authors.initials: CA
authors.lastname: Yamazaki
authors.forename: M Conceição C
authors.initials: MC
authors.lastname: Mamone
authors.forename: Elza S
authors.initials: ES
authors.lastname: Ikejiri
authors.forename: Jairo T
authors.initials: JT
authors.lastname: Hidal
authors.forename: Luiza K
authors.initials: LK
authors.lastname: Matsumura
authors.forename: Flávio C
authors.initials: FC
authors.lastname: Hojaij
authors.forename: Onivaldo
authors.initials: O
authors.lastname: Cervantes
authors.forename: Márcio
authors.initials: M
authors.lastname: Abrahão
authors.forename: Reinaldo P
authors.initials: RP
authors.lastname: Furlanetto
authors.forename: Rui M B
authors.initials: RM
authors.lastname: Maciel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D011446:Prospective Studies; D013964:Thyroid Neoplasms / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology*; D016606:Thyroid Nodule / Q000150:complications* / Q000175:diagnosis; D013997:Time Factors