title: Surgical treatment for dominant malignant nodules of the isthmus of the thyroid gland: A case control study.
abstract: BACKGROUND
  Appropriate surgical treatment of papillary thyroid carcinomas (PTC) located in the isthmus remains controversial. The aim of this study was to evaluate the clinicopathological characteristics of PTC of the isthmus compared to tumors located in the thyroid lobes, to identify differences between PTC and microcarcinomas of the isthmus, and to use these findings to establish total thyroidectomy as an appropriate surgical resection for treating these tumors.
  
  
  METHODS
  We retrospectively analyzed 2239 patients subjected to total thyroidectomy. PTC was diagnosed in 575 patients, of whom 521 had dominant malignant nodule located in thyroid lobes and 54 had a dominant carcinoma located in the isthmus. Patients with isthmic PTC were divided in Group A (n = 27) with PTC >10 mm and Group B (n = 27) with microcarcinoma ≤ 10 mm.
  
  
  RESULTS
  In univariate analysis, multifocality (p = 0.019), lymph node metastasis (p < 0.001), mean tumor size (p = 0.028) and age ≥ 45 (p = 0.036) were significantly associated with PTC with dominant nodule in the isthmus. Additional analysis of PTC groups (>10 mm vs ≤ 10 mm) in isthmus showed that multifocality, bilaterality, histological subtype and lymph node metastasis were not significantly different between the two groups.
  
  
  CONCLUSIONS
  Our results suggest that PTCs located in the isthmus were more likely to be associated with multifocal disease, lymph node involvement and capsule invasion, than carcinomas in other thyroid regions. Therefore, total thyroidectomy could be considered as an appropriate surgical treatment for papillary carcinomas located in the isthmus regardless of size.
authors.affiliation: Second Department of Propedeutic Surgery, School of Medicine, University of Athens, Laikon General Hospital, 17 Ag. Thoma Str., 11527 Athens, Greece.
authors.forename: Theodore
authors.initials: T
authors.lastname: Karatzas
authors.affiliation: Department of Anatomy, Medical School of Alexandroupolis, Democritus University of Thrace, Greece.
authors.forename: Georgios
authors.initials: G
authors.lastname: Charitoudis
authors.affiliation: Department of Anatomy, Medical School of Alexandroupolis, Democritus University of Thrace, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Vasileiadis
authors.affiliation: Department of Anatomy, Medical School of Alexandroupolis, Democritus University of Thrace, Greece.
authors.forename: Stylianos
authors.initials: S
authors.lastname: Kapetanakis
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, Venizeleio-Pananeio Hospital, Herakleion, Greece; Department of Otolaryngology - Head and Neck Surgery, Royal London Hospital, Barts and the London Trust, London, United Kingdom. Electronic address: j.vasileiadis@yahoo.gr.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Vasileiadis
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000473:pathology / Q000601:surgery*; D002291:Carcinoma, Papillary / Q000473:pathology / Q000556:secondary / Q000601:surgery*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000473:pathology / Q000601:surgery*; D013965:Thyroidectomy / Q000379:methods*; D055815:Young Adult
keywords: Malignant; Nodule; Surgical treatment; Thyroid isthmus; Total thyroidectomy