Differentiating between Cushing's disease of pituitary origin and ectopic ACTH syndrome of extra-pituitary origin remains a major challenge to the clinician because of limitations in the diagnostic accuracy of the high-dose dexamethasone suppression test. Routine use of inferior petrosal sinus sampling (IPSS) is therefore advocated by some authors for these patients. We present our preliminary experience of IPSS in 7 consecutive patients with Cushing's disease and discuss how the results impacted on the patients' management.
Ocular hypertension caused by endogenous Cushing syndrome from an ectopic adrenocorticotropic hormone-producing tumor is rare. We report an 11-year-old boy who presented with intraocular pressures (IOPs) of 50 mm Hg in both eyes. Surgical resection of the tumor was performed with subsequent normalization of serum cortisol and IOP levels.