Endocrine Abstracts

Introduction: Cushing’s syndrome is a rare endocrine disorder characterized by excess cortisol secretion. It can be caused by various etiologies, including ACTH-dependent and ACTH-independent forms. We report a case of a 78-year-old male who presented with severe hypertension, refractory hypokalemia, and severe hypercortisolaemia, diagnosed with ACTH-dependent Cushing’s syndrome with bilateral adrenal hyperplasia.

Case Presentation: A 78-year-old male presented to emergency department with severe hypertension of 215/125 mmHg and refractory hypokalaemia of 2.4 mmo/l(Normal: 3.5 - 5.1) not normalizing after 120 mmol of IV potassium chloride replacement. Serum cortisol level was significantly elevated at 2934 nmol/l(Normal: 172 - 497), with a paired ACTH level of 250 ng/l(Normal: 7.2 - 63.3) confirming ACTH-dependent etiology. Imaging studies, including CT adrenals, MRI pituitary, CT Chest Abdomen and Pelvis, Ga68 Dotatate and FDG PET scan, failed to demonstrate an ectopic source of ACTH or a pituitary adenoma. With the clinical suspicion of Cushing’s crisis, he was immediately treated with IV Etomidate infusion to control severe hypercortisolaemia.

Treatment and Outcome: During admission, he developed recurrent infections including atypical pneumonia, C. diff and CoViD -19, likely due to his immunosuppressed state resulting from prolonged hypercortisolaemia. He was stabilized with ketoconazole, metyrapone and prednisolone as a block-and-replace regimen. Following treatment, his cortisol level gradually decreased to 162 nmol/l. He was planned for inferior petrosal sinus sampling (IPSS) to assess pituitary source of ACTH. Because of anatomical difficulties in cannulation of right jugular vein, his IPSS was unsuccessful, and the procedure was abandoned. Bilateral adrenalectomy was considered, but after achieving clinical stability on metyrapone and prednisolone as block-and-replace, this was not carried out.

Discussion: This case highlights the diagnostic and therapeutic challenges of managing ACTH-dependent Cushing’s syndrome. Imaging studies are essential to identify the underlying cause of Cushing’s syndrome, and bilateral adrenal enlargement can be challenging to diagnose due to its rarity. The use of Etomidate infusion in the management of Cushing’s crisis has been well established in the literature in managing severe hypercortisolaemia by inhibiting steroidogenesis.

Conclusion: In conclusion, this case report emphasizes the importance of timely diagnosis and management of Cushing’s Crisis, which is a rare endocrine emergency. Severe hypercortisolaemia can lead to multiple complications, including severe hypertension, refractory hypokalaemia, high risk infection, venous thromboembolism, and GI bleed with high mortality. High index of clinical suspicion and prompt management with IV Etomidate infusion remains pivotal managing Cushing’s crisis.