Endocrine Abstracts

Introduction: While iatrogenic Cushing’s syndrome is common, acquired isolated ACTH deficiency is a rare condition. Hypophysitis is the most common cause, and while most recently published cases are associated with immunotherapy, it may also be idiopathic. Hereby we present a case of cortical adrenal atrophy secondary to idiopathic acquired ACTH deficiency, in order to raise awareness about this condition.

Material and Methods: Review of the patient’s clinical record and the relevant literature.

Results: A non-smoking 49-year old man complained of progressive weakness in the last 6 months, being presently unable to climb a flight of stairs or to stand from the sitting position without arm support. He had a history of iron deficiency anaemia, B12 vitamin deficiency, sporadic use of nasal decongestant, a head trauma at the age of 15 without any known sequelae, and a lack of any significant glucocorticoid intake. He reported no personal or family history of autoimmune disease. The patient was initially assessed by a cardiologist who could not find any cardiological reason that justified the symptoms. Therefore, he was referred to the Endocrinology and Internal Medicine departments. He also complained of progressive asthenia, frequent headaches and loss of about 10% of his previous body weight. He had no sexual dysfunction and his physical examination showed no hyperpigmentation, his BP was 136/78 mmHg, HR 69 bpm, and the rest of the examination was unremarkable as well. His lab test showed normal natremia, kalemia and blood count. Free T4, TSH, LH, FSH, testosterone, aldosterone, plasma renin activity and metanephrines were normal. Plasma cortisol was undetectable, and ACTH was 2.5 pg/ml (inadequately low). Anti-adrenal and anti-hypophysis antibodies were both negative. A CT scan showed marked bilateral cortical atrophy of both adrenals, without any other abnormalities. An MRI scan of the hypophysis and hypothalamus was normal. The patient’s clinical condition improved markedly with standard oral hydrocortisone substitution (30 mg per day).

Conclusions: Acquired isolated clinical deficiency of ACTH is an elusive clinical condition that can be caused by hypophysitis in the absence of glucocorticoid intake, whose origin might be related to autoimmunity. In this clinical case hypophysitis could be excluded, and therefore the most likely diagnosis would be idiopathic acquired isolated ACTH deficiency, as the head trauma he suffered may play a role in the development of this condition. We recommend follow-up with lab and imaging tests in order to find new possible deficiencies and/or abnormalities.