Pituitary Adenoma Recurrence Suspected on Central Hyperthyroidism Despite Empty Sella and Confirmed by 68Ga-DOTA-TOC PET/CT.

Thyrotropin-secreting pituitary adenomas are very rare tumors, known to present overexpression of somatostatin receptor subtype 2 and which may consequently demonstrate abnormal uptake on Ga-DOTA-TOC PET/CT. A 67-year-old woman with a history of operated pituitary macroadenoma presented with symptoms of hyperthyroidism including a large goiter. Her serum thyroid hormone levels were in favor of central hyperthyroidism. Pituitary MRI depicted an empty sella but visualized an ambiguous lesion centered on the left sphenoidal sinus. Complementary Ga-DOTA-TOC PET/CT finally demonstrated intense uptake by the sphenoidal lesion, confirming recurrence of the pituitary adenoma.