title: Frozen section in a cytological diagnosis of thyroid follicular neoplasm.
abstract: OBJECTIVE
  Fine-needle aspiration biopsy is the most accurate diagnostic test for thyroid nodules, its only limitation being the diagnosis of follicular neoplasm that does not distinguish between benign and malignant follicular lesions.
  
  
  METHODS
  To determine the utility of intraoperative frozen-section analysis in cases of a cytological diagnosis of follicular neoplasm, a retrospective review of 66 patients with a solitary thyroid nodule and follicular neoplasm who underwent thyroid surgery was carried out.
  
  
  METHODS
  Fine-needle aspiration was classified following the Papanicolaou Society of Cytopathology Classification, and frozen section was defined as malignant or "deferred." If a malignant diagnosis was made by frozen-section analysis, a total thyroidectomy was carried out. The extension of thyroid surgery in the deferred cases was based on the definitive histological diagnosis.
  
  
  RESULTS
  Sixty-four cases were classified as deferred, and two as suspect for malignancy. Among the 64 deferred cases, 15 were malignant in the final pathological findings, and 49 were benign. The two suspect cases were papillary carcinoma. Frozen-section analysis classified 2 of 17 (11.7%) cases as follicular variant of papillary carcinoma that could not be diagnosed by cytological study. However, these two cases had a strong clinical evidence of malignancy.
  
  
  CONCLUSIONS
  The routine use of frozen-section analysis is useless in cases of cytological diagnosis of follicular neoplasm on fine-needle aspiration biopsy, because of the low probability of achieving the diagnosis of follicular carcinoma and the inability to provide additional information apart from the clinical and the cytological data.
authors.affiliation: Endocrinology Service, Hospital Universitari Germans Trias I Pujol, Carretera Canyet s/n, 08916 Badalona, Catalonia, Spain.
authors.forename: Núria
authors.initials: N
authors.lastname: Alonso
authors.forename: Anna
authors.initials: A
authors.lastname: Lucas
authors.forename: Isabel
authors.initials: I
authors.lastname: Salinas
authors.forename: Eva
authors.initials: E
authors.lastname: Castella
authors.forename: Anna
authors.initials: A
authors.lastname: Sanmartí
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000473:pathology*; D000328:Adult; D001707:Biopsy, Needle; D002291:Carcinoma, Papillary / Q000473:pathology*; D005260:Female; D005629:Frozen Sections / Q000379:methods; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000473:pathology*