Endogenous Cushing syndrome from an ectopic adrenocorticotropic hormone production as a rare cause of ocular hypertension

Ocular hypertension secondary to high endogenous steroid load in Cushing's disease

This case report describes a 35-year-old Caucasian man who was referred to the glaucoma clinic with high intraocular pressure (IOP) after routine optometrist assessment. He was diagnosed with ocular hypertension (OHT) and the management plan was for monitoring without treatment. Three months later, he presented to the endocrine clinic with symptoms of Cushing's disease and was diagnosed with an adrenocorticotropic hormone secreting pituitary microadenoma. His symptoms preceded his presentation at both departments by 5 years. He underwent definitive surgical treatment of his adenoma via transsphenoidal resection. At 1-year follow-up in glaucoma clinic, it was noted that his IOP had normalised. Due to his high endogenous cortisol level at diagnosis, long disease duration, the pattern of IOP rise and subsequent normalisation after treatment, it is suggestive that his OHT is secondary to his Cushing's disease. There are infrequent reports of this association in published literature.

Ophthalmic clues to the endocrine disorders

PURPOSE

Eye is a vital sense organ and reflects the physical and mental wellbeing of a person. Detailed examination of the eye is an essential part in the clinical evaluation of patients with any systemic disorder. The interaction between ophthalmologists and endocrinologists is often limited to Graves' ophthalmopathy and diabetic retinopathy. However, there are many ophthalmic manifestations, which are characteristically seen in endocrine disorders. In this review, we shall discuss the ocular manifestations of the endocrine syndromes excluding the Graves' ophthalmopathy and diabetic retinopathy.

METHODS

We performed a PubMed search of articles published in English showing the ophthalmic features in the endocrine disorders. Relevant cited articles were also retrieved.

RESULTS

Most of the publications included in the review were case reports and review articles. Many endocrine disorders have characteristic manifestations pertaining to the various structures of the eye. The involvement is seen from the external structures of the eye to the inner most layers of the retina. Many ocular-endocrine syndromes also exist with characteristic clues to the clinical diagnosis.

CONCLUSION

The endocrinologists need to be aware of these ocular signs that help in the early diagnosis of the underlying disorder. A syndromic approach is essential in the diagnosis of endocrinopathy in patients presenting with ophthalmic features.

The search for ectopic ACTH production in a 9-year-old boy

Ectopic ACTH syndrome (EAS) is rare in children and is challenging to differentiate from Cushing's disease. A 9-year-old boy presented with a history of worsening fatigue, muscle weakness, weight gain and acne, and he appeared cushingoid with central obesity and hyperpigmentation of his palmar creases. Investigations demonstrated an elevated ACTH and an elevated morning cortisol that did not suppress with low or high dose dexamethasone suppression tests. Brain imaging inconsistently showed a small pituitary lesion. Chest and abdomen computed tomography (CT) showed adrenal hyperplasia and a liver hemangioma. [18F]fluorodeoxyglucose positron emission tomography CT was normal. Ultrasound and abdominal magnetic resonance imaging (MRI) also showed a liver hemangioma. Bilateral inferior petrosal sinus sampling, however, was consistent with ectopic ACTH production. An octreotide scan revealed a small focus of increased activity in the liver, which was the likely source of ectopic ACTH production. The patient was managed with metyrapone followed by a wedge liver resection. Pathology showed a well-differentiated neuroendocrine tumor (NET) that stained positive for ACTH. Post-operatively, the signs and symptoms of EAS are resolving and his hypothalamic-pituitary-adrenal axis is recovering. This case describes the first pediatric patient with EAS caused by a liver NET. It illustrates the challenges in localizing the source of ectopic ACTH and treating this rare condition.