Endocrine Abstracts

Introduction: Although Graves’ disease is often accompanied by other autoimmune diseases, only a few cases of Graves’ disease accompanied by pheochromocytoma have been described.

Herein we report a rare case of coexisting Graves’ disease and pheochromocytoma.

Observation: A 50-year-old male patient was referred to our department for the evaluation of right adrenal incidentaloma of 80*66 mm. He had a history of coronary disease and he presented with heat intolerance, diaphoresis, palpitations, intense headaches, excessive nervousness, mood disturbances as well as a rapid weight loss of 30 kg during the last one year.

On physical examination, he had a body weight of 53 kg, a body mass index of 16.5 kg/m² and a blood pressure (BP) of 120/75 mm Hg in supine position and 95/60 in standing position.

However his blood profile showed paroxysmal hypertension with peaks of 160/110 mm Hg. The pulse rate was 132 beats per minute (bpm). He had neither goiter nor exophthalmos. Electrocardiogram (ECG) showed a regular sinus tachycardia at 138 bpm with signs of left ventricular hypertrophy.

Laboratory tests indicated diabetes mellitus with a fasting blood sugar of 2.86 g/l and a glycated hemoglobin of 7.9%, hyperthyroidism with a low TSH of 0.05 μIU/ml, an elevated free T4 of 1.96 ng/dl and urinary metanephrines and normetanephrines were greater than 20 time normal values. TSH receptors antibodies were positive.

Thyroid scintigraphy showed homogeneous increased uptake involving the whole thyroid gland.

The diagnosis of coexisting Graves’ disease and pheochromocytoma was established. Treatment with prazosin, benzylthiouracil and insulin was then initiated. Propranolol was added progressively. The patient was planned for right adrenalectomy after achieving euthyroid state.

Conclusion: Pheochromocytoma and Graves’ disease are known by their similar clinical features making their differential diagnosis difficult. In our case, adrenal incidentaloma evaluation had revealed the pheochromocytoma. Otherwise, a meticulous physical examination and detailed laboratory investigations are needed in order to make a precise diagnosis.