Subclinical Cushing's disease accompanied by malignant hypertension and diabetes mellitus

A 53-year-old woman was admitted because of hypertension and diabetes mellitus. Elevated diastolic blood pressure, hypertensive retinopathy and renal dysfunction indicated malignant hypertension. Adrenocorticotropic hormone (ACTH) and cortisol levels were high although there were no Cushingoid features. One mg dexamethasone administration decreased neither ACTH nor cortisol levels. Brain magnetic resonance imaging revealed a left pituitary tumor (7 mm x 6 mm). Upon removal, the tumor showed positive ACTH staining by immnohistochemistry, and was diagnosed as pituitary ACTH-secreting adenoma (Cushing's disease). Her blood pressure, renal function, blood glucose and hormone levels subsequently improved. Malignant hypertension and deteriorated diabetes mellitus may have been due to subclinical Cushing's disease.