Primary Adrenal Insufficiency: a diagnostic challenge

• Published in: Acta clinica belgica (English ed. Online) 2016-05, Vol.71 (S3), p.7
• Main Authors: Wierckx, K, Vandecasteele, S J, Van den Bruel, A
• Format: Article
• Language: English
• Subjects: Adrenal glands; Skin; Tuberculosis
• ISSN: 1784-3286; 2295-3337

We present a case of a 42-year-old man who was referred to the Department of Endocrinology because of muscle soreness and increased skin pigmentation with suspicion of adrenal insufficiency. No other complaints were present. The patient had a history of arterial hypertension, at the moment well-controlled despite of stopping antihypertensive medication and gastroesophageal reflux disease with daily use of a proton pump inhibitor (Esomeprazole 20 mg). There was no relevant family history apart from tuberculosis (TB) of his mother. He denied travel to the tropics or drug use. Physical examination showed a normal blood pressure, increased pulse rate and a marked hyperpigmentation of the skin and mucosa. Laboratory findings showed low morning cortisol of 2 pig/dl (6.2-18 (pg/dL), low DHEAS of 67 pg (88.9-427 pg), high renine of 15187 plU/ml (2.8-39.9 plU/ml) and high ACTH level of > 1250 pg/l (< 46 ng/L). Short corticotrophin test did not evoke a marked increase in serum cortisol. The diagnosis of primary adrenal insufficiency (PAI) was made and the patient was started on hydrocortisone and fludrocortisone therapy. Assessment for anti-adrenal antibodies and catecholamine secretion were negative. 17-OH progesterone levels and very long chain fatty acids were normal. A computed tomography (CT) scan of the abdomen demonstrated bilateral adrenal enlargement with one nodule in each adrenal gland (right: nodule with maximum diameter 44 mm, Hounsfield Units (HU): 40; left: maximum diameter 14 mm, HU: 37). Further assessment with whole-body fluorine-18 fluorodeoxyglucose positron emission tomography-CT (FDG PET-CT) examination showed increased FDG uptake at both adrenals (more pronounced in the right adrenal gland) as well as an increased uptake at some axillary lymph nodes. A tuberculin skin test showed to be positive and may reflect co-existence of TB carriage or TB of the adrenal glands. Due to absence of extra-adrenal TB, further work-up with ultrasonic guided puncture of one adrenal gland is planned 17th of August. PAI is a rare disease with a reported prevalence of about 100-140 cases per million in Western Societies. The most common cause of PAI is auto-immunity (up to 90% in Western countries). Adrenal TB is a relatively infrequent cause of PAI in developed countries, whereas in developing countries, TB remains a major cause of PAI. However, recent increases in human migration have contributed to increased rates of TB in Western Societies. The differential dia