Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
2498801 | Experimental and Toxicologic Pathology | 2016 | 6 Pages |
Histopathological and immunohistochemical characteristics of spontaneous pituitary adenomas found in dwarfs derived from Wistar Hanover GALAS are being described for the first time. The adenomas were seen in 5 males aged 48 weeks or older and in 11 females aged 34 weeks or older. Immunohistochemically, 13 cases without post-mortem changes could be evaluated; 4 Thyroid stimulating hormone (TSH)-containing adenomas, 2 TSH- and prolactin (PRL)-containing adenomas, 1 PRL-containing adenoma and 6 all-negative adenomas that did not react to any of the examined anti-hormone antibodies. The most common type were TSH-containing pituitary adenomas (a total of 6 cases; 46%) which occurred exclusively in females; the tumors consisted mainly of basophilic or amphophilic cells with bizarre nuclei and neoplastic cells and were positive for TSH in varying degrees. The TSH-containing pituitary adenomas, a characteristic of this mutant rat, could be induced by genetically-controlled hypothyroidism in dwarf rats, with higher sensitivity to possible disturbance of the pituitary–thyroid axis in females.