A unique case of ectopic Cushing's syndrome from a thymic neuroendocrine carcinoma

Case report: A challenging case of severe Cushing's syndrome in the course of metastatic thymic neuroendocrine carcinoma with a synchronous adrenal tumor

Ectopic ACTH syndrome (EAS) remains one of the most demanding diagnostic and therapeutic challenges for endocrinologists. Thymic neuroendocrine tumors account for 5%-10% of all EAS cases. We report a unique case of a 31-year-old woman with severe EAS caused by primary metastatic combined large-cell neuroendocrine carcinoma and atypical carcinoid of the thymus. The patient presented with severe hypercortisolemia, which was successfully controlled with continuous etomidate infusion. Complex imaging initially failed to detect thymic lesion; however, it revealed a large, inhomogeneous, metabolically active left adrenal mass infiltrating the diaphragm, suspected of primary disease origin. The patient underwent unilateral adrenalectomy, which resulted in hypercortisolemia resolve. The pathology report showed an adenoma with adrenal infarction and necrosis. The thymic tumor was eventually revealed a few weeks later on follow-up imaging studies. Due to local invasion and rapid progression, only partial resection of the thymic tumor was possible, and the patient was started on radio- and chemotherapy.

Cushing's syndrome: a combined treatment with etomidate and osilodrostat in severe life-threatening hypercortisolemia

Endogenous Cushing's syndrome (CS) is associated with increased morbidity and mortality. Early diagnosis and initiation of therapy are essential, but effective treatment remains a challenge. In a long-term follow-up, biochemical control of hypercortisolemia, especially when severe, is difficult to achieve. Life-threatening hypercortisolemia is difficult to control due to the limitations of pharmacotherapy, including its side effects, and may require etomidate infusion in the intensive care unit (ICU) to rapidly lower cortisol levels. The effectiveness of hypercortisolemia management can be increased by a dual blockade of cortisol production. We report the efficacy, safety, and tolerability of combined therapy with two steroidogenesis inhibitors, etomidate, and osilodrostat, in a 32-year-old woman diagnosed with severe ACTH-dependent hypercortisolemia, subsequently maintaining a stable level of cortisol with osilodrostat monotherapy. This approach enabled achievement of relatively rapid control of the hypercortisolemia while using an etomidate infusion and concomitant increasing doses of oral osilodrostat applying a "titrations strategy." Our experience shows that it is worth taking advantage of the synergistic anticortisolic action of etomidate with osilodrostat.

A rare initial presentation of a thymic neuroendocrine tumor as Cushing's syndrome

While evaluating the cause of Cushing's syndrome, biochemical confirmation should be sought first as imaging studies might misdirect the diagnosis toward the wrong problem. One of the rare secondary causes that should be kept in mind while evaluating Cushing's syndrome is the thymic neuroendocrine tumor.