Transient Thyrotoxicosis Accompanied by Panhypopituitarism Caused by Ruptured Rathke's Cleft Cyst

We describe a rare case of transient thyrotoxicosis secondary to painless thyroiditis accompanied by panhypopituitarism caused by ruptured Rathke's cleft cyst. A 32-year-old man presented with vomiting and diarrhea. Laboratory data showed that he had transient hypercalcemia, primary thyrotoxicosis due to painless thyroiditis and panhypopituitarism. The sellar magnetic resonance imaging showed cystic macroadenoma. He underwent surgical exploration. Histological examination showed a ruptured Rathke's cleft cyst. Our case suggests that, although rare, it is important to recognize the possibility of coexistence of hypopituitarism in patients with primary thyrotoxicosis.