title: Intrathyroidal differentiated thyroid carcinoma: tumor size-based surgical concepts.
abstract: BACKGROUND
  Total thyroidectomy (TT) remains the treatment of choice for differentiated thyroid carcinomas (DTCs), but a limited approach can be proposed when tumors are at an early stage and limited to a single lobe. The aim of this study was to analyze the pathologic and clinical aspects of a retrospective series of DTCs in an attempt to determine whether these features might prove useful for limiting the surgical strategy in selected cases.
  
  
  METHODS
  From 2000 to 2005, a total of 2798 patients (637 males, 2161 females; mean age 44.6 years) underwent TT for papillary thyroid carcinoma in our department. The histologic features considered were size, histologic subtype and capsule of the tumor, its multifocality/bilaterality, infiltration of the thyroid capsule, and the presence of nodal metastases.
  
  
  RESULTS
  Statistical analysis revealed that among tumors < or = 1 cm the presence of the tumor capsule, infiltration of the thyroid capsule, bilaterality, and the presence of node metastases were all significantly lower when the tumor size was < or = 0.5 cm (p < 0.0001). Furthermore, patients with bilateral carcinomas demonstrated a significantly higher presence of a tumor capsule (p = 0.012), infiltration of the thyroid capsule (p < 0.0001), and node metastases (p < 0.0001) and a higher incidence of the "tall-cells" variant (p < 0.0001) when compared to the unilateral population.
  
  
  CONCLUSIONS
  Based on these data it is suggested that tumors < or = 1 cm cannot be considered a homogeneous class of DTCs. Nevertheless, in tumors < or = 0.5 cm the absence of a "tall-cells" variant and the absence of infiltration of the thyroid capsule might be useful for avoiding an unnecessary completion thyroidectomy after lobectomy.
authors.affiliation: Department of Surgery, University of Pisa, Via Roma 67, 56100, Pisa, Italy, p.miccoli@dc.med.unipi.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Miccoli
authors.forename: Michele N
authors.initials: MN
authors.lastname: Minuto
authors.forename: Clara
authors.initials: C
authors.lastname: Ugolini
authors.forename: Erica
authors.initials: E
authors.lastname: Panicucci
authors.forename: Piero
authors.initials: P
authors.lastname: Berti
authors.forename: Marco
authors.initials: M
authors.lastname: Massi
authors.forename: Fulvio
authors.initials: F
authors.lastname: Basolo
mesh_terms: D000328:Adult; D002291:Carcinoma, Papillary / Q000473:pathology* / Q000601:surgery*; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery*; D013965:Thyroidectomy / Q000379:methods*; D016896:Treatment Outcome