Endocrine Abstracts

JOINT921

Introduction: Ectopic Cushing’s syndrome is a rare condition caused by a paraneoplastic secretion of ACTH by a tumor outside the pituitary or adrenal glands. The symptoms associated with hypercortisolism are similar to other types of Cushing’s syndrome but they can be more severe and have a rapid onset. Excluding pituitary adenoma and discovering the ectopic source of ACTH is crucial in the diagnostics. The treatment of choice is a surgical removal of the ACTH-secreting tumor. The surgery and recovery could however be complicated by the overt hypercortisolism and that is why a pharmacological treatment is recommended before the surgery in severe cases. There are several steroidogenesis inhibitors available including osilodrostat which is the most novel one.

Observation: We present a case of a 45-year-old man without any significant comorbidities. He was presented to an endocrinologist by his general practitioner because of a rapidly onseting and drug-resistant arterial hypertension and hyperlipidemia along with typical traits of Cushing’s syndrome (central obesity, rounded face, swelling…). His early morning cortisol was elevated and not suppressible by dexamethasone and free urine cortisol was 11 times the upper limit of normal. ACTH was extremely elevated however other pituitary hormones were normal. No adenoma was visible on the pituitary MRI nevertheless there was a solitary 22 mm nodule in the upper left pulmonary lobe on the PET/CT scan. The S3 segmentectomy was indicated and to reduce the complications and improve recovery we started the osilodrostat therapy three weeks before the surgery. After one week we increased the initial dose from 20 to 40 mg daily. On the day of surgery we managed to decrease the free urine cortisol to 2 times the upper limit of normal and significantly reduce the antihypertensive therapy. The surgery was performed without any complications and an atypical lung carcinoid was then histologically described with highly positive ACTH staining. We stopped osilodrost the day after surgery and started hydrocortisone replacement instead. ACTH, serum, salivary, and urine cortisol then gradually normalised and we were able to withdraw hydrocortisone slowly. We now only follow the patient in cooperation with the pulmonary oncologist.

Conclusion: Pharmacological treatment is primarily used in patients with Cushing’s syndrome who are contraindicated for surgery. However, it can be beneficial as a bridge to surgery, aiming to reduce complications and improve recovery. The novel steroidogenesis inhibitior osilodrostat, in our case, proved itself to be very capable of doing so if properly dosed.