گزارش يك مورد هيپرپلازي منتشره تيروييد (گواتر مادرزادي) در جنين بز از كلينيك تخصصي دانشكده دامپزشكي دانشگاه آزاد اسلامي واحد گرمسار

A case report of diffuse hyperplasia of thyroid (congenital goiter) in goat fetus from clinic of faculty of veterinary science, Azad Islamic University, Garmsar

Nonneoplastic and noninflammatory enlargement of the thyroid gland develops in all domestic animals, birds, and other submammalian vertebrates. In March 2008 a native female goat which died before clinical examination because of severe disease was refered to postmortem hall of the faculty of veterinary science, Azad Islamic University Garmsar for postmortem examination. While conducting internal examination , two fetuses were evacuated from the uterus of carcass which were significant because of enlarged thyroid glands. In internal examination of fetuses two swellen lobes of thyroid gland with approximate dimentions of 8.5x3.5x3 cm located symmetrically on both sides of the cranial aspect of trachea were observed. The two affected lobes removed from carcase were dark red in color and hard in texture. In histopathological studies , an extensive interfollicular capillary network developed under the influence of longterm TTH stimulation. Follicles were irregular in size and shape in hyperplastic goiter because they contained varying amounts of colloid that was highly eosinophilic and vacuolated. Some follicles were collapsed from the lack of colloid. Their lining epithelial cells were columnar and had a deeply eosinophilic cytoplasm and small hyperchromatic nuclei that often were situated in the basilar portion of the cell. The follicles were lined by single or multiple layers of hyperplastic follicular cells , that in some follicles , may form papillary projections into the lumen. On the basis of macroscopic and microscopic findings in thyroid glands of fetuses , the defect was diagnosed as diffuse hyperplastic goiter. VetJ.of Islamic.Azad. Univ., Garmsar Branch. 4,3:111-117,2008.