Endocrine Abstracts

Background: Ectopic Cushing’s syndrome (ECS) is a rare and severe condition at times presenting acutely with intense hypercortisolism. The intensity of hypercortisolism can be disproportionate to underlying tumoral condition, and associated life-threatening complications are common arising suddenly. Hypercortisolism must be controlled rapidly pending definitive treatment of tumoral source to avoid life-threatening consequences.

Case Summary: 31-year-old Asian female presented with acute confusion, emotional liability, lethargy, and weight loss of 15 kgs over four months. She had moon facies, hirsutism and buffalo hump. She had one miscarriage and was diagnosed with PCOS one year ago by her GP. Initial tests showed refractory hypokalaemia (2.7 mmol/l) and raised random cortisol (4450 nmol/l). Repeated tests confirmed hypercortisolism with raised ACTH (366pg/l), normal plasma metanephrines and tumour markers. CT scan of thorax, abdomen and pelvis showed thymic mediastinal mass with bilateral adrenal hyperplasia. MRI scan of pituitary was normal. She was started on block and replace regime with metyrapone and hydrocortisone. After MDT discussion she underwent video-assisted thoracoscopic surgery to remove the thymic mass. Histopathology showed thymic large cell neuroendocrine carcinoma. PET scan post-surgery showed local active residual disease and she had failed cortisol suppression (293 nmol/l) on 48-hour low dose dexamethasone suppression test. No Ga68-DOTATOC scan avid regional nodal disease or distant metastasis identified. She underwent removal of tumour remnant followed by chemotherapy and radiotherapy. During radiotherapy, she had symptoms of cortisol excess. Biochemistry confirmed recurrence of hypercortisolism with normal CT scan of thorax, abdomen and pelvis. She was recommenced on metyrapone and hydrocortisone.

Conclusion: This case highlights the complexities in diagnosis and management of ECS presenting initially as a medical emergency necessitating immediate medical intervention to control severe hypercortisolism and associated life-threatening complications. Prompt diagnosis and rapid initiation of medical treatment for hypercortisolism is essential to reduce the burden of cortisol-induced comorbidities.