Cushing's syndrome with mediastinal lipomatosis.

ediastinal lipomatosis is a rare benign condition characterized by deposition of a large amount of mature adipose tissue within the mediastinum. The common etiologies are obesity, exogenous or endogenous Cushing’s syndrome, alcohol abuse and rarely it can be idiopathic.1 It is more common now than thought previously, as imaging modalities like computerized tomography (CT) and magnetic resonance imaging (MRI) decisively diagnose this condition. Imaging features include smooth bilateral widening of the superior mediastinum with relative lucency and no definable mass in the lateral x-ray. It is usually asymptomatic, but may sometimes present with compressive symptoms, and often poses a diagnostic dilemma. A 27-year-old male was admitted with excessive weight gain, typical purple striae on the abdomen, generalized increased pigmentation, proximal muscle weakness and psychotic behavior. He had no history of steroid abuse. On examination, he had centripetal obesity, buffalo hump, broad purple striae on the abdomen, pulp atrophy and generalized increased pigmentation. He was hypertensive with blood pressure of 190/110 mm Hg. Biochemical parameters were: serum sodium 135 meq/L; potassium 2.7 meq/L; fasting blood glucose 294 mg/dl; 0800h cortisol, 1000 nmol/L; 2100h cortisol, 640 nmol/L; and adrenocorticotrophic hormone at 2100h 138 pg/ml. Cortisol levels after overnight in low dose and high dose dexamethasone suppression were 520, 960 nmol/L and 780 nmol/L; suggestive M