title: CD98 expression is decreased in papillary carcinoma of the thyroid and Hashimoto's thyroiditis.
abstract: OBJECTIVE
  CD98 is a component of the large neutral amino acid transporter (LAT), which is a cell surface amino acid transporter. CD98 also binds to and activates beta(1)-integrin, promoting anchorage-independent growth. CD98 expression is increased in a variety of carcinomas but its distribution in the normal and neoplastic thyroid gland has not been reported. The aim was to examine the immunohistochemical expression of CD98 in normal and diseased thyroid tissue.
  
  
  RESULTS
  One hundred and forty thyroid cases were selected from the archives of the Department of Pathology, including normal controls, neoplasms (follicular adenoma, follicular carcinoma and papillary carcinoma) and non-neoplastic conditions (multinodular goitre, Graves' disease and Hashimoto's thyroiditis). Immunohistochemistry for CD98 was performed and each case was scored for proportion of cells and intensity of immunoreactivity. In normal thyroid, there was moderately strong expression of CD98 in the lateral cell membranes of follicular cells. A similar pattern of expression was seen in follicular adenoma, minimally invasive follicular carcinoma, multinodular goitre and Graves' disease. In most cases of papillary carcinoma and in the inflamed areas of Hashimoto's thyroiditis, expression of CD98 was decreased.
  
  
  CONCLUSIONS
  CD98 expression is down-regulated in thyroid papillary carcinoma; this may relate to the better prognosis associated with many of these tumours.
authors.affiliation: Department of Pathology, Royal Infirmary of Edinburgh, Edinburgh, UK.
authors.forename: Catriona E
authors.initials: CE
authors.lastname: Anderson
authors.forename: Catriona
authors.initials: C
authors.lastname: Graham
authors.forename: Michael M
authors.initials: MM
authors.lastname: Herriot
authors.forename: Hassan M
authors.initials: HM
authors.lastname: Kamel
authors.forename: Donald M
authors.initials: DM
authors.lastname: Salter
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000378:metabolism; D000236:Adenoma / Q000378:metabolism; D002291:Carcinoma, Papillary / Q000378:metabolism*; D015536:Down-Regulation; D027261:Fusion Regulatory Protein-1 / Q000378:metabolism*; D006111:Graves Disease / Q000378:metabolism; D050031:Hashimoto Disease / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D011379:Prognosis; D013961:Thyroid Gland / Q000378:metabolism*; D013964:Thyroid Neoplasms / Q000378:metabolism*
chemical_list: D027261:Fusion Regulatory Protein-1