[Hyperthyroidism caused by non-neoplastic inappropriate TSH secretion]

We report a case of hyperthyroidism due to non-neoplastic inappropriate thyrotrophin secretion in a 31 year old woman. Increased T3 and THS levels after thyroidectomy led us to suspect the diagnose. Serum levels were further increased by TRH and only partially suppressed by triiodothyronine and computerised axial tomography showed a normal sellar region. These features are characteristic of inappropriate TSH secretion due to thyrotroph resistance to thyroid hormones. Bromocriptine and octreotide were ineffective in lowering TSH levels. Pregnancy and breastfeeding postponed 3,5,3'-triiodothyroacetic acid therapy.