Ectopic Cushing's syndrome: experience from a tertiary care centre

Area of Science:

• Endocrinology
• Oncology

Background:

• Ectopic adrenocorticotropic hormone (ACTH) secretion is a rare cause of endogenous Cushing's syndrome, accounting for approximately 10% of cases.
• This study details the experience with ectopic Cushing's syndrome (ECS) at a tertiary care center in North India over two decades.

Purpose of the Study:

• To describe the clinical characteristics, diagnostic methods, and management outcomes of patients with ectopic Cushing's syndrome.
• To highlight the challenges in diagnosing and treating this rare endocrine disorder.

Main Methods:

• Retrospective review of 12 patients diagnosed with ECS between 1985 and 2006.
• Analysis of presenting manifestations, clinical signs, biochemical investigations (plasma cortisol, ACTH, high-dose dexamethasone suppression test), imaging, and treatment outcomes.

Main Results:

• The study included 12 patients (7 men) with a mean age of 27.6 years; diagnosis was delayed by an average of 18.3 months.
• Common manifestations included weight loss, hyperpigmentation, and infections, while signs included cuticular atrophy, hypertension, bruising, and proximal myopathy.
• Tumor sources included thymic carcinoid (5), bronchial carcinoid (3), islet cell carcinoid (1), hepatic carcinoid (1), gut carcinoid (1), and medullary thyroid carcinoma (1).
• Surgical tumor removal was the treatment of choice, but only two patients achieved a sustained cure, with others experiencing residual disease or recurrence.

Conclusions:

• Ectopic Cushing's syndrome is a rare but serious condition with diverse clinical presentations, often mimicking classical Cushing's syndrome.
• The disease is associated with significant morbidity and mortality.
• Surgical resection of the ectopic ACTH-producing tumor is the preferred treatment modality.