European Congress of Endocrinology 2009
Istanbul, Turkey
25 April 2009 - 29 April 2009
European Society of Endocrinology
Somatostatin receptor 2 expression in cold thyroid nodules exceeds that of hot thyroid nodules, papillary thyroid carcinoma and Graves’ disease
1Section of Endocrinology and Metabolism of Marmara Medical School, Altunizade/Istanbul, Turkey; 2Third Medical Department, University of Leipzig, Leipzig, Germany; 3University Clinic Schleswig-Holstein, Schleswig-Holstein, Germany; 4Department of Pathology of Marmara Medical School, Altunizade/Istanbul, Turkey; 5General Surgery Department of Marmara Medical School, Altunizade/Istanbul, Turkey.
Objective: The specificity and cellular origin of the SSRS findings in CN, HN, PC and GD is currently unclear and partially contradicts the well defined action of somatostatin on thyroid cell signaling. Therefore, we systematically evaluated SSTR2 expression in benign cold (CN) and hot thyroid nodules (HN), papillary carcinomas (PCs) and Graves’ disease (GD) in comparison with intraindividual control surrounding tissues (ST) by means of immunohistochemistry.
Design and methods: Tissue sections from 29 HN, 22 CN, 19 PC and their surrounding tissues and 8 GD thyroids were immunostained for SSTR2. with an affinity-purified rabbit polyclonal antibody against SSTR2 (Bio Trend, Cologne, Germany) in a final dilution of 1:1000. Membranous SSTR2 staining was quantitated by evaluating 10 high power fields (HPF) systematically distributed along the largest diameter of the tissue section.
Results: The area covered by thyroid epithelial cells in 10 HPF expressed as median in mm2 was 0.53 for CN, 0.44 for HN, 1.5 for PC, 1.3 for GD and 0.3 for the surrounding tissues. The percentage of SSTR2 positive thyroid epithelial cells/area covered by thyroid epithelial cells in 10 HPF expressed as % was 16.6% for CN, 2.0% for HN, 3.7% for PC and 3.9% for GD and 2.4% for the ST of all groups.
Conclusions: Our study shows that SSTR2 can be immunohistochemically demonstrated in normal, hyperplastic and neoplastic thyroid cells. In addition to the immunocompetent cells infiltrating the thyroid gland in Graves’ disease also the thyroid epithelial cells in Graves’ disease express SSTR2 receptors. The repeated SSRS detection in PC is mostly related to SSTR2 expression on thyroid epithelial cells and not dependent on their lymphocytic infiltration. The highest density of SSTR2 receptors was detected in CN. This has to be considered when using SSRS for the diagnosis and localisation of radioiodine negative thyroid cancer.
Endocrine Abstracts (2009) 20 P82