title: Thyroglobulin measurement in fine-needle aspiration biopsy of metastatic lymph nodes after rhTSH stimulation.
abstract: BACKGROUND
  Thyroglobulin measurement in the washout of the needle used in fine-needle aspiration cytology (FNAC) has been proposed for the early detection of lymph node metastasis both in patients with or without serum thyroglobulin antibodies; however, up to now, there have been no reports that recombinant human thyrotropin (rhTSH) stimulation modifies thyroglobulin measurement in lymph node aspirates.
  
  
  METHODS
  We described, after rhTSH stimulation, the switching from undetectable to detectable levels of thyroglobulin in fine-needle aspiration fluid from a suspected metastatic lymph node in 2 patients.
  
  
  RESULTS
  We hypothesized that thyroglobulin levels in the lymph node increased after rhTSH stimulation. The excess thyroglobulin saturates all thyroglobulin antibody binding sites and becomes detectable, explaining why it was undetectable when TSH was suppressed.
  
  
  CONCLUSIONS
  On the basis of our experience, we suggest submitting to thyroglobulin measurement in the washout of the needle used in FNAC all patients with detectable serum thyroglobulin antibody after rhTSH stimulation.
authors.affiliation: Department of Medical and Surgical Sciences, Internal Medicine and Endocrinology Unit, University of Brescia, Brescia, Italy. cappelli@med.unibs.it
authors.forename: Carlo
authors.initials: C
authors.lastname: Cappelli
authors.forename: Ilenia
authors.initials: I
authors.lastname: Pirola
authors.forename: Elvira
authors.initials: E
authors.lastname: De Martino
authors.forename: Elena
authors.initials: E
authors.lastname: Gandossi
authors.forename: Elena
authors.initials: E
authors.lastname: Cimino
authors.forename: Francesca
authors.initials: F
authors.lastname: Samoni
authors.forename: Barbara
authors.initials: B
authors.lastname: Agosti
authors.forename: Enrico Agabiti
authors.initials: EA
authors.lastname: Rosei
authors.forename: Claudio
authors.initials: C
authors.lastname: Casella
authors.forename: Maurizio
authors.initials: M
authors.lastname: Castellano
mesh_terms: D044963:Biopsy, Fine-Needle; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D013954:Thyroglobulin / Q000032:analysis* / Q000097:blood; D013964:Thyroid Neoplasms / Q000097:blood / Q000473:pathology*; D013972:Thyrotropin / Q000032:analysis* / Q000097:blood
chemical_list: D013972:Thyrotropin; D013954:Thyroglobulin