title: TSH levels are associated with increased risk of thyroid carcinoma in patients with nodular disease.
abstract: BACKGROUND
  Several studies have shown an increased risk of thyroid malignancies in patients with elevated TSH levels, even if these levels fell within the normal range. The aim of this study was to evaluate the relationship between TSH and risk of malignancy in patients with thyroid nodules.
  
  
  METHODS
  We included 622 patients with thyroid nodules evaluated by fine needle aspiration and/or thyroidectomy and diagnosed by cytology or histology. Clinical and laboratory data, such as gender, weight, ultrasound findings, serum TSH, and free T4, were obtained from medical records or collected during each patient's first visit to our centre, prior to any intervention.
  
  
  RESULTS
  Thyroid cancer was more prevalent in males (p = 0.012) and in patients with a solitary nodule (p < 0.01). Malignant tumours were predominantly solid, whereas benign tumours were solid or mixed (p = 0.053). The carcinoma risk in patients with thyroid nodules increased with increasing serum TSH concentration, with a significant elevation in patients with serum TSH levels above 1.64 mU/L (p < 0.001). This relationship persisted even when the subgroup of patients undergoing thyroidectomy was analysed separately. Patients with follicular lesions presented with significantly higher TSH levels compared to patients with benign cytology (p < 0.001). We also found correlation between elevated TSH and tumour size (p = 0.005).
  
  
  CONCLUSIONS
  Our results suggest that in patients with nodular thyroid disease the carcinoma risk rose in parallel with serum TSH concentration, with significant increases evident in patients with serum TSH greater than 1.64 mU/L.
authors.affiliation: Endocrinology Division, Hospital de Clinicas, Federal University of Parana (SEMPR). tayfighera@yahoo.com.br.
authors.forename: Tayane Muniz
authors.initials: TM
authors.lastname: Fighera
authors.forename: Camila Luhm Silva
authors.initials: CL
authors.lastname: Perez
authors.forename: Nadia
authors.initials: N
authors.lastname: Faris
authors.forename: Patricia Cristina
authors.initials: PC
authors.lastname: Scarabotto
authors.forename: Thamires Tixiliski
authors.initials: TT
authors.lastname: da Silva
authors.forename: Teresa Cristina Santos
authors.initials: TC
authors.lastname: Cavalcanti
authors.forename: Cleo Otaviano
authors.initials: CO
authors.lastname: Mesa Junior
authors.forename: Fabiola
authors.initials: F
authors.lastname: Miasaki
authors.forename: Gilberto Jorge
authors.initials: GJ
authors.lastname: da Paz Filho
authors.forename: Gisah Amaral
authors.initials: GA
authors.lastname: de Carvalho
mesh_terms: D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012306:Risk; D013964:Thyroid Neoplasms / Q000097:blood* / Q000453:epidemiology; D013965:Thyroidectomy; D013972:Thyrotropin / Q000097:blood*
chemical_list: D013972:Thyrotropin
keywords: TSH; malignancy; thyroid nodules