Endocrine Abstracts

Introduction: Cushing’s syndrome is rare disease with annual incidence 2/ million. It carries a high mortality rate if untreated. ACTH independent Cushing’s with Adrenal adenoma is responsible for 10% of cases. This is a case of a young gentleman with back pain, vertebral fracture, in presence of left adrenal incidentaloma, normal MRI pituitary, and hormonal profile indicative of possible non-detectable central pituitary lesion, diagnosis of likely adrenal Cushing’s was established. Left adrenalectomy was performed with smooth recovery, histopathology has confirmed a benign nature of adrenal adenoma.

Case presentation: 37-year-old gentleman presented in A&E with chest pain, radiating to the back. PMH: hypertension on triple therapy. Family history: non-significant In view of chest pain, he had a CT Aortogram to rule out aortic dissection, this showed left adrenal incidentaloma and T7 vertebral body collapse. In view of left adrenal mass and vertebral fracture he had further investigations to rule out cortisol excess. At this point overight dexamethasone suppression test was arranged.

Investigations: CT angiogram: left adrenal mass 3.4 cm, 5 HU likely benign adenoma. MRI Spine: subacute T 7 vertebral body fracture. FSH 7.9 U/l LH 3.7 U/l Testosterone 5.3 nmol/l. Normal Prolactin, Thyroid, IGF1 and random cortisol. In view of left adrenal mass, he was referred to Endocrine clinic. Ongoing vision disturbance and weight gain was reported. On Examination: BP 137/69 BMI 35.9, evident abdominal striae. He failed to suppress high dose overnight dexamethasone suppression test. [cortisol 123 nMol/l with ACTH 19 (0-46 ng/l)], and low dose dexamethasone suppression test [(72 nMol/l with ACTH 9)]. Bone densitometry: Lumbar spine Osteopenia T-score -1.9 Z-score -1.8. Elevated UFC (107 nmol/l), and UFC excretion index (25 nmol/24 hours). MRI pituitary: normal.

Differential Diagnosis: 1. Established Cushing’s disease diagnosis with possible left adrenal driven etiology. 2. On the other hand, he had inappropriately low FSH and LH for an extremely low testosterone level, and his ACTH was not suppressed. There is a possibility of small pituitary adenoma which is non-detectable on pituitary MRI.

Treatment: 1. Metyrapone2. laparoscopic left adrenalectomy

Outcome: Metyrapone was stopped and his post-operative low dose dexamethasone suppression test confirmed his Cushing’s has now been cured. Histopathology: benign adrenal adenoma. Reduced anti-hypertensive medications to one medicine

Future Plan: 1. Blood pressure and osteopenia monitoring - expected to improve.2. Monitor for possible post-operative corticotrope tumor growth and adrenal insufficiency.3. Gonadotrophin and testosterone re-assessment.4. Genetic test to rule out MEN.