Rare Challenges in Diagnosing Cushing's Syndrome and Primary Aldosteronism: A Case Report of a Female With a Negative Workup.

Cushing's syndrome with concurrent primary aldosteronism (PA) is a rare presentation, and establishing an early diagnosis is imperative to preventing morbidity and long-term sequelae. The diagnosis is established by sequential lab work, showing an elevated cortisol and aldosterone level. Taking the above into consideration, it is evident that repeatedly negative results on all three tests can present an extremely challenging case. In this report, we discuss a female who presented with an adrenal incidentaloma and features suggestive of primary hyperaldosteronism as well as Cushing's syndrome but no elevations in serum, urine, or salivary cortisol. In this study, we present a 37-year-old female with resistant hypertension and tachycardia. She had several features suggestive of Cushing's syndrome including resistant hypertension, proximal muscle weakness, weight gain, easy bruising, hair loss, and a history of tachycardia and chest pain. Examination revealed an obese female with thin silvery abdominal striae. The patient's labs revealed normal serum cortisol, urine-free cortisol (UFC), late-night salivary cortisol, and a normal dexamethasone suppression test. An abdominal computed tomography (CT) scan revealed a right adrenal mass measuring 2.1 x 1.5 x 2.5 cm. Due to a high index of suspicion, adrenal venous sampling was performed, which revealed high levels of cortisol and aldosterone in the right vein, confirming the diagnosis. The patient subsequently underwent a right adrenalectomy. She developed hypotension post-op, leading to the diagnosis of glucocorticoid-remediable aldosteronism.