What is the diagnosis for a 41-year-old female with hypercortisolism (elevated morning cortisol), elevated Dehydroepiandrosterone sulfate (DHEAS), a body mass index (BMI) of 21, and a normal adrenal gland Magnetic Resonance Imaging (MRI)?

Differential Diagnosis for Elevated AM Cortisol and DHEAS in a 41-year-old Female

Single Most Likely Diagnosis

• Polycystic Ovary Syndrome (PCOS): This condition is common in women of reproductive age and is associated with hormonal imbalances, including elevated androgens like DHEAS. Elevated morning cortisol can also be seen due to the stress of chronic hormonal imbalance or associated with insulin resistance, which is common in PCOS.

Other Likely Diagnoses

• Congenital Adrenal Hyperplasia (CAH): Although less common, CAH can present in adulthood, especially the non-classical form, with symptoms of androgen excess (elevated DHEAS) and sometimes cortisol dysregulation.
• Idiopathic Hypercortisolism: This condition involves elevated cortisol levels without a clear cause, such as Cushing's syndrome, but without the full spectrum of symptoms or signs.
• Adrenal Incidentaloma with Subclinical Cushing's Syndrome: Although the adrenal MRI is normal, it's possible that a small, functioning adrenal tumor was missed, or the patient has subclinical Cushing's syndrome, which might not always present with the typical Cushingoid features.

Do Not Miss Diagnoses

• Cushing's Syndrome: Despite the normal adrenal MRI, Cushing's syndrome due to an ectopic source (e.g., a small cell lung cancer) or a pituitary source (Cushing's disease) must be considered. These conditions can be life-threatening if not diagnosed and treated promptly.
• Adrenal Carcinoma: Although rare, adrenal carcinoma can produce both cortisol and androgens, leading to the observed laboratory findings. A normal MRI does not entirely rule out this diagnosis, especially if the tumor is small or the imaging was not of high quality.

Rare Diagnoses

• Familial Cushing's Syndrome: Rare genetic syndromes that can lead to Cushing's syndrome, such as familial Cushing's syndrome, should be considered, especially if there's a family history of similar conditions.
• McCune-Albright Syndrome: This rare genetic disorder can lead to precocious puberty, café-au-lait spots, and a variety of endocrine disorders, including Cushing's syndrome and hyperandrogenism.
• Steroidogenic Factor 1 (SF1) Deficiency: A rare condition that affects the development of the adrenal glands and gonads, potentially leading to abnormalities in steroid hormone production.