Endocrine Abstracts

Thyrotropin-secreting pituitary tumors are <1% of pituitary adenomas. Clinical manifestations are similar to other forms of hyperthyroidism. Most of them are diagnosed as macroadenoma (microadenomas <10%).

Case 1: A 48 years old woman with menopause presented 6 years ago, consulting in 2009 for weight loss and palpitations. She had elastic goiter and distal tremor. Blood test: TSH 8.66 μUI/ml (0.2–4.2), FT₄ 4.7 ng/dl (0.7–1.55), FT₃ 10 pg/ml (2–4), α-TSH 5.2 UI/l (0.02–0.9), negative antithyroid antibodies, FSH 10.2 mUI/ml, LH 4.7 mUI/ml, estradiol 28 pg/ml and the rest of pituitary hormones in normal range. Pituitary MRI: macroadenoma (2 cm) with suprasellar invasion, contacting optic chiasm. Campimetry: normal. Treatment was started: propanolol 30 mg/day and octreotide 20 mg/28 days. Six months after: clinical improvement and restoration of menstruation, TSH 0.93, FT₄ 1.22, α-TSH 0.42 and slight decrease in tumour size, respecting the optic chiasm (MRI). Transsphenoidal surgery performed (April 2010) and immunohistochemistry was positive to TSH–GH. Immediate postoperative results: TSH 0.04, FT₄ 1.1. After 8 weeks: panhypopituitarism (TSH 1.6, FT₄ 0.6, α-TSH 0.2). After 6 months, patient is stable with sustitutive treatment and there’s no tumour in MRI.

Case 2: A 49 years old woman with history of complete hysterectomy, consulting in 2008 for TSH 8, FT₄ 2.99 and positive antithyroid antibodies in a blood test. She presented irritability and irregular goiter. Pituitary MRI: microadenoma (0.6 cm). α-TSH 3.2. She started octeotride 20 mg/28 days. After 6 months TSH 1.7, FT₄ 1.08 and pituitary lesson was stable. Transsphenoidal surgery (2011) with immunohistochemistry positive to TSH. 8 weeks postsurgery: TSH 2.3, T₄ 0.88, α-TSH 0.34. 6 months after, thyroid axis is normal and there’s no tumour in MRI.

Conclusions: We present two different clinical forms of this tumor type, at initial diagnosis and in their postoperative evolution, probably related to tumor size.

However in both cases we observed clinical and analytical response to early medical treatment with somatostatin analogues.