title: Secondary tumours revealed during fine needle aspiration of the thyroid--analysis of prevalence and characteristics of ultrasound image.
abstract: BACKGROUND
  Metastases to the thyroid are revealed at autopsy with a frequency of 2-24%; however, clinically they appear less frequently, at 0.1-3%. The aim of the study was analysis of the frequency of revealing metastases to the thyroid (TM) and to the regional lymph nodes (NM) (neoplasms other than primary thyroid tumours) in preoperative diagnostics of the thyroid in patients with positive (C+) and negative (C-) history of cancer; analysis of ultrasound (US) images of metastases.
  
  
  METHODS
  Results of US/fine needle aspiration (FNA) of the thyroid in 1276 C+ patients and 18,947 C- patients.
  
  
  RESULTS
  TM and NM were diagnosed/suspected in 57 patients (0.3% of all examined; 40 TM, 22 NM, 5 both), and their frequency was higher in the C+ group (2.9% vs. 0.1% in C-, p < 0.0001). In the C+ group, diagnosis of metastasis accounted for 72.3% of FNA results from the category "malignant neoplasm"; in the C- group it was 9.5% (p < 0.0001). The highest relative frequency of TM was found for cancers infiltrating thyroid by direct extension (> 10%), lymphomas (7.7%), and kidney (5.3%) and lung (4.9%) cancers. The mean age of patients with metastasis (63.9 ± 11.7 years) was similar to that of the C+ group and higher than the C- group (53.9 ± 14.8 years, p < 0.0001). The proportion of males among the patients with metastasis was three-fold higher than in the patients without metastasis (p < 0.0001). TM lesions presented suspicious borders in US twice as often as primary cancers .
  
  
  CONCLUSIONS
  Metastases to the thyroid are rare; however, for patients with a history of cancer, their presence is more likely than primary thyroid cancer. US/FNA imaging of metastases allows the selection of patients requiring further diagnostics and treatment.
authors.forename: Kamila
authors.initials: K
authors.lastname: Wysocka
authors.forename: Aneta
authors.initials: A
authors.lastname: Małyska
authors.forename: Damian
authors.initials: D
authors.lastname: Zadworny
authors.forename: Stanisław
authors.initials: S
authors.lastname: Sporny
authors.forename: Mariusz
authors.initials: M
authors.lastname: Klencki
authors.forename: Ewa
authors.initials: E
authors.lastname: Woźniak-Oseła
authors.forename: Włodzimierz
authors.initials: W
authors.lastname: Koptas
authors.forename: Bożena
authors.initials: B
authors.lastname: Popowicz
authors.affiliation: Department of Morphometry of Endocrine Glands, Chair of Endocrinology, Medical University of Lodz. dsk@tyreo.umed.lodz.pl.
authors.forename: Dorota
authors.initials: D
authors.lastname: Słowińska-Klencka
mesh_terms: D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000556:secondary*
keywords: fine needle aspiration biopsy; metastasis; thyroid; thyroid cancer; ultrasound