title: Metastases to the thyroid gland: prevalence, clinicopathological aspects and prognosis: a 10-year experience.
abstract: BACKGROUND
  Metastases to thyroid (TM) are rarely observed in the clinical practice.
  
  
  OBJECTIVE
  To assess the prevalence, clinicopathological aspects and prognosis of TM, and to evaluate the role of thyroidectomy in the management of TM.
  
  
  METHODS
  The pathology files (databases) of two Italian Pathology Units were searched for thyroid cytology (FNAC) and histology reports covering the time period January 1993 through December 2003.
  
  
  RESULTS
  Thirty-six cases of TM were found, accounting for 0.13% of thyroidectomies and 0.07% of FNAC. The main site of origin of TM was the lung, followed by oesophagus, breast and kidney. TM patients were divided into two groups, based on whether they were (Group 1) or were not (Group 2) submitted to surgery. Thirty-five subjects diagnosed with the same primary tumours as TM patients, but without TM, served as controls. The mean patient age, the mean time from diagnosis of primary tumour to TM detection, and the mean survival time did not significantly differ in Group 1 and Group 2 (63.2 +/- 1.6 vs. 66.6 +/- 2.9 years, 24.7 +/- 8.6 vs. 19.7 +/- 4.4 months and 24.3 +/- 4.9 vs. 39 +/- 9.9 months, respectively). In contrast, the mean time from detection of TM to death was longer in Group 1 than in Group 2 (14.3 +/- 2.5 vs. 4.5 +/- 0.5 months, respectively; P = 0.002). The overall survival of TM patients and control subjects was not significantly different (33.7 +/- 6.6 vs. 32.3 +/- 6 months).
  
  
  CONCLUSIONS
  TM is a rare event, is more frequent in patients older than 60 years, and has the same impact on prognosis as nonthyroidal metastases. Although thyroidectomy may be useful to avoid further dissemination of the primary tumour in case of solitary TM, it does not contribute to prolonging patient's life.
authors: Department of Internal Medicine, Endocrinology Unit, University of Modena and Reggio Emilia, Italy.
authors: Giampaolo
authors: G
authors: Papi
authors: Guido
authors: G
authors: Fadda
authors: Salvatore Maria
authors: SM
authors: Corsello
authors: Stefania
authors: S
authors: Corrado
authors: Esther Diana
authors: ED
authors: Rossi
authors: Elena
authors: E
authors: Radighieri
authors: Antonella
authors: A
authors: Miraglia
authors: Cesare
authors: C
authors: Carani
authors: Alfredo
authors: A
authors: Pontecorvi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001707:Biopsy, Needle; D001943:Breast Neoplasms / Q000473:pathology / Q000601:surgery; D002114:Calcinosis; D002292:Carcinoma, Renal Cell; D003110:Colonic Neoplasms / Q000473:pathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology / Q000601:surgery; D008175:Lung Neoplasms / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating; D015995:Prevalence; D011379:Prognosis; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D013965:Thyroidectomy; D016896:Treatment Outcome