A 62 year old diabetic with weight loss and lung lesions

Case history A 62 year old retired paratrooper was referred by his general practitioner with new onset diabetes and a 13 year history of hypertension, which had recently been difficult to treat. He complained of frequent headaches, ankle swelling, thirst and urinary frequency. Previously, he had received various antihypertensive treatments, including diuretics, β-blockers, calcium channel antagonists, and angiotensin-converting enzyme (ACE) inhibitors. He was currently taking prazosin 1.5 mg and bendrofluazide 5 mg daily. He smoked 20 cigarettes·day-1, and had been diagnosed as suffering from chronic obstructive pulmonary disease, for which he took inhaled salbutamol as required. His alcohol intake was 80 g·week -1 . On examination, the only abnormal findings were a blood pressure of 190/110 mmHg, and mild pitting-oedema of both ankles. Fundoscopy showed grade I hypertensive changes, and his urine tested positive for glucose only. Initial investigations showed a normal full blood count, sodium 140 mmol·L -1 , potassium 2.6 mmol·L -1 , urea 6.2 mmol·L-1, creatinine 71 µmol·L-1. Random serum glucose was 12 mmol·L -1 , and the major fraction of glycosylated haemoglobin (HbAIC) 10.2% (normal range up to 5.9%). Chest radiography showed a small left-sided pleural effusion. A resting electrocardiogram (ECG) indicated left ventricular hypertrophy, and an echocardiograph revealed moderately good left ventricular function, with normal valves. A diagnosis of diabetes mellitus was made, and dietary treatment initiated. When this failed, gliclazide 80 mg b.d. was added. The patient's hypertension was treated with bendrofluazide 2.5 mg and enalapril 10 mg daily, and the hypokalaemia was corrected with Sando-K. On review 1 month later, blood sugars were still high, HbAIC was still 10.2%, and blood pressure 170/100 mmHg. Because of tiredness, general malaise and weakness, the patient was then prescribed twice daily insulin. After another month, the patient returned complaining of weight loss and depression. Oral candidiasis, balanitis, and generalized pigmentation were now apparent. The ankle oedema was much worse, and a proximal myopathy was noted. Hypokalaemia was still present. Tests were performed and gave the following results: Random cortisol, 2,000 mmol·L-1 (normal <800 mmol·L-1); high dose dexamethasone suppression test, no suppression; adrenocorticotrophic hormone (ACTH), 161 ng·L-1 (normal <100 ng·L-1); computed tomography (CT) of the pituitary gland, partially empty sella, no mass lesion; CT of the abdomen, a 1 cm mass in the right adrenal gland, otherwise normal.