Resolution of insulin treated diabetes and hypertension following resection of an asymptomatic phaeochromocytoma

Abstract

The clinical and biochemical manifestations which occur in diseases associated with hormone excess, such as phaeochromocytoma, usually resolve when the hormone levels are normalised. This patient with long-standing diabetes mellitus and hypertension was incidentally found to have a completely asymptomatic phaeochromocytoma. Both hypertension and diabetes completely resolved on surgical extirpation of the tumour.We present the case of a 53-year-old male patient with diabetes and hypertension, with a blood pressure of 150/80mmHg and an HbA1c of 9% on three antihypertensive agents and insulin therapy. He was found to have a slightly raised alanine aminotransferase of 81IU/L on routine tests. An abdominal ultrasound incidentally revealed a large right adrenal mass. He had no symptoms suggestive of a phaeochromocytoma. His urinary noradrenaline excretion was raised at 4636nmol (70-580nmol/24hours). An MRI scan confirmed the right adrenal mass. He underwent an adrenalectomy and the histology confirmed a phaeochromocytoma. Subsequently, his insulin requirements fell and all therapy for diabetes and hypertension was withdrawn.While diabetes and hypertension are very common, an asymptomatic phaeochromocytoma may rarely be responsible, and its removal curative, for both conditions.