title: Ectopic expression of follicle-stimulating hormone receptors in thyroid tumors.
abstract: BACKGROUND
  In normal conditions follicle-stimulating hormone receptors (FSHR) are expressed in the ovary and the testis. They can also be expressed in gonadal tumors. However, recently we have found FSHR immunostaining in pituitary adenomas, adrenal tumors and neuroendocrine tumors (carcinoids). The aim of this study was to determine whether the same occurs in thyroid tumors.
  
  
  METHODS
  Thirty-six samples of surgically excised thyroids were examined. Follicle-stimulating hormone receptors immunostaining was performed on paraffin sections using the rabbit anti-human FSHR polyclonal antibody raised against a 1-190 amino acid sequence from the human FSHR (sc-13935, Santa Cruz).
  
  
  RESULTS
  Normal thyroid follicles do not show immunopositivity for FSHR. The same concerns the majority of benign lesions, diagnosed as hyperplasia nodularis or thyroid adenomas. However, positive FSHR immunostaining in some follicles was observed. In all but one thyroid cancer (15 papillary, 10 follicular cancers and one case of anaplastic thyroid cancer) 10-100% of tumor cells exhibit positive FSHR immunostaining. In about 40% of samples FSHR immunoreactivity can be observed also in the endothelia of intrathyroidal blood vessels. This immunopositivity was more frequent in the samples of thyroid cancers (13/27) than in benign lesions (2/9).
  
  
  CONCLUSIONS
  Ectopic positive FSHR immunostaining is also present in thyroid cancers, and, to a lesser degree, in benign lesions but not in the normal thyroid epithelium.
authors.affiliation: Department of Immunoendocrinology, Chair of Endocrinology, Medical University of Lodz, Lodz, Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Pawlikowski
authors.affiliation: Department of Neuroendocrinology, Chair of Laboratory Medicine, Medical University of Lodz, Lodz, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Jaranowska
authors.affiliation: Department of Neuroendocrinology, Chair of Laboratory Medicine, Medical University of Lodz, Lodz, Poland.
authors.forename: Hanna
authors.initials: H
authors.lastname: Pisarek
authors.affiliation: Department of Pathology of Tumors, Chair of Oncology, Medical University of Lodz, Lodz, Poland.
authors.forename: Robert
authors.initials: R
authors.lastname: Kubiak
authors.affiliation: Department of Neuroendocrinology, Chair of Laboratory Medicine, Medical University of Lodz, Lodz, Poland.
authors.forename: Julita
authors.initials: J
authors.lastname: Fuss-Chmielewska
authors.affiliation: Department of Neuroendocrinology, Chair of Laboratory Medicine, Medical University of Lodz, Lodz, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Winczyk
keywords: follicular cancer; nodular hyperplasia; papillary cancer