Endocrine Abstracts

Introduction

Thyrotropin-secreting pituitary adenoma is a rare cause of hyperthyroidism which must be differentiated from other etiologies of inappropriate TSH secretion.

Observation:

We report the case of a 49 years old male patient with no particular pathological history, addressed for thyrotoxicosis (weight loss, irritability, thermophobia, dyspnea and palpitation) with no goiter or ophtalmopathy. Echocardiography showed dilated cardiomyopathy and pulmonary arterial hypertension. Hormonal testing revealed elevated TSH levels 27 and 69 mUI/l, associated with elevated FT4 level 29 pmol/l. Pituitary MRI showed intra and suprasellar expansive process, invading the base of the skull, measuring 46.7 × 67.9 × 50.5 mm with moderate hydrocephalus. Neurological examination revealed frontal syndrome and damage to the left nerve III. Exploration of the other pituitary axes concluded to central adrenal insufficiency and central hypogonadism with elevated GH levels; IGF1 and prolactin levels were not elevated. Surgical resection of adenoma was rejected by neurosurgeons due to its large size and operative risk. The evolution under hydrocortisone, treatment of heart failure including beta blocker, bromocriptin and somatostatin analogs was initially favorable with amelioration of hyperthyroidism symptoms and regression of behavioral disorder. However, control MRI revealed an increase in the volume of the adenoma 76 × 66 × 67 mm with significant loco regional invasion. Patient’s evolution was marked by death secondary to cerebral herniation.

Conclusion

Invasive Thyrotropin-secreting pituitary adenomas are a therapeutic management problem. If pituitary surgery is contraindicated or declined, medical treatment reduces the symptoms of hyperthyroidism but tumor evolution is unpredictable.