Endocrine Abstracts

Background: Autoimmune polyendocrinopathy-candidiasis–ectodermal dystrophy (APECED) is a rare monogenic disorder characterized by various loss-of-function mutations in the AIRE gene. Clinical manifestations in this case included chronic mucocutaneous candidiasis, hypoparathyroidism, primary adrenal insufficiency, type 1 diabetes, and vitiligo. Additionally, the patient had a history of primary hypothyroidism and epilepsy.

Clinical Case: Hypopituitarism was first suspected based on routine follow up bloods showing a low TSH (0.01 mU/l) with stable free T4 (14.50 pmol/l) on unchanged thyroxine dose and low ACTH (3.6 pg/ml) with no clinical evidence of glucocorticoid over-replacement. A subsequent pituitary panel revealed hypogonadotropic hypogonadism, with FSH 0.3 IU/l (1.5 - 12.4), LH 0.3 IU/l (1.7 - 8.6), and testosterone levels at <0.09 nmol/l (7.98 - 29.14). Additionally, growth hormone of 0.5, and IGF-1 68 µg/l (88.3 - 246) and a prolactin of 343 mU/l (86 - 324). The patient reported low energy, low libido and erectile dysfunction. Visual field testing revealed a left eye temporal hemianopia, however this was complicated by a right vitreous haemorrhage due to diabetes, causing a near complete loss of vision in the right eye. MRI of the pituitary gland revealed a 2.9 cm T1 bright, non-enhancing cystic lesion extending from a normally sized pituitary fossa into the suprasellar cistern, with signal characteristics suggestive of proteinaceous material. Review of historical record revealed an MRI brain done 5 years previously which did not show any obvious pituitary abnormality. Given visual fields defect, the patient underwent transphenoidal resection. Histological diagnosis confirmed a Rathke’s cleft cyst. High index of suspicion is required to diagnosed hypopituitarism in patients with multiple endocrinopathies on long term hormonal replacement.