• Age 14 or older

• Active or treated overt Cushing's (due to pituitary, ectopic, or adrenal tumor), mild adrenal Cushing's syndrome (MACS), or a silent corticotroph tumor

• The diagnosis of CS or MACS will be made by the PI, based on the below Endocrine Society guidelines, the patient's clinical presentation, and the PI's judgment.

‣ Diagnostic criteria for ACTH-dependent Cushing's are according to the Endocrine Society and European Society of Endocrinology guidelines and include: Elevated 24-hour urinary free cortisol (UFC), normal or elevated plasma ACTH, elevated midnight salivary cortisol levels, or classic dexamethasone suppression testing for CD (morning cortisol \> 5 ug/dL after 1 mg overnight of classic 2-day low dose test) and a pituitary lesion on MRI. If patient does not have any of these results, pathology of ACTH tumor may confirm presence of disease.

⁃ Diagnostic criterion for MACS is according to the European Society of Endocrinology guidelines: Classic dexamethasone suppression testing for CD (morning cortisol \>1.8 µg/dL after 1 mg overnight).

• For pituitary Cushing's patients, if the patient demonstrates non-classic testing or no pituitary lesion is seen on MRI then petrosal sinus sampling or positive surgical pathology will be used to confirm pituitary source of Cushing's. Clinical or biochemical remission after surgery will also confirm pituitary source.

• Ectopic Cushing's will be confirmed by petrosal sinus sampling and appropriate imaging tests, or positive surgical pathology.

• Adrenal Cushing's will be confirmed by a suppressed plasma ACTH value and identification of an adrenal lesion on CT or MRI, or positive surgical pathology.

• Silent corticotroph tumors will be defined by surgical pathology demonstrating positivity for ACTH, in the absence of clinical and biochemical features of Cushing's syndrome.

• In lieu of MRI, surgical, or laboratory reports, physician's assessment note including mention of results will also be used as source for eligibility purposes.