Adrenal Tumour

An adrenal tumour, or adrenal mass, is any benign or malignant neoplasm of the adrenal gland, some of which are notable for overproducing endocrine hormones. Adrenal cancer includes malignant tumours such as neuroblastoma, adrenocortical carcinoma, and some pheochromocytomas.

While most adrenal pheochromocytomas and all adrenocortical adenomas are benign, they can cause significant health issues by disrupting hormonal balance.

Metastasis to the Adrenals

Metastasis to one or both adrenal glands is the most common form of malignant adrenal lesion, second only to benign adenomas. The primary tumours in such cases usually originate from lung cancer (39%), breast cancer (35%), malignant melanoma, gastrointestinal tract cancer, pancreas cancer, and renal cancer.

Tumours of the Adrenal Cortex

The adrenal cortex consists of three layers of endocrine cells producing essential steroid hormones, including glucocorticoids, aldosterone, and sex hormones. Both benign and malignant tumours in this area can significantly impact clinical outcomes.

Adrenocortical Adenoma

Adrenocortical adenomas are benign tumours of the adrenal cortex, commonly found in 1-10% of people during autopsies, and are more frequent in older individuals. These adenomas are increasingly detected due to advanced imaging techniques like CT and MRI. While most are non-functional, some produce hormones causing endocrine disorders such as Cushing's syndrome, Conn's syndrome, virilisation in females, or feminisation in males. These functional adenomas are surgically curable.

Adrenocortical Carcinoma

Adrenocortical carcinoma (ACC) is a rare, aggressive cancer that can occur in both children and adults. These carcinomas may be functional, producing hormones, or non-functional. Due to their deep retroperitoneal location, they are often diagnosed late, by which time they may have invaded large vessels and metastasized. Surgery is the primary treatment, but the prognosis remains poor, with chemotherapy, radiation therapy, and hormonal therapy as additional options.

Tumours of the Adrenal Medulla

The adrenal medulla, located at the centre of the adrenal gland, consists of neuroendocrine cells producing epinephrine. Tumours here include neuroblastoma and pheochromocytoma, which may also arise in extra-adrenal sites.

Neuroblastoma

Neuroblastoma, an aggressive cancer of immature neuroblastic cells, is common in children, typically presenting as a rapidly enlarging abdominal mass. Despite often spreading at diagnosis, many cases are highly curable, especially if limited to the liver, skin, and bone marrow. Treatment includes surgery, radiation therapy, and chemotherapy.

Pheochromocytoma

Pheochromocytoma is a tumour composed of chromaffin cells, producing large amounts of catecholamines, leading to high blood pressure and cardiac issues. Diagnosis is through urinary catecholamine metabolites. Treatment involves initial anti-adrenergic drugs followed by surgery.

Incidentalomas

An adrenal incidentaloma is an adrenal tumour discovered accidentally during imaging for unrelated issues. Tumours under 3 cm are generally benign. Hormonal evaluation involves dexamethasone suppression tests and urine tests for catecholamines. Imaging follow-ups are recommended for benign-appearing tumours.

Treatment

Surgical

Surgery is the most effective treatment for adrenal carcinomas, although often not feasible for many patients. A 2018 Cochrane review compared laparoscopic retroperitoneal adrenalectomy and laparoscopic transperitoneal adrenalectomy, finding the former reduced late morbidity and recovery times, though evidence quality was low.

Future Diagnostic Tools

Recent studies have looked at circulating microRNAs (miRNA) as less-invasive biomarkers for adrenal diseases. While promising, results are variable, necessitating further research on larger cohorts to validate miRNAs' utility in prognosis and malignancy.

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Self-assessment MCQs (single best answer)

What is an adrenal tumour?

Which of the following cancers is most commonly associated with metastasis to the adrenal glands?

What is the primary function of the adrenal cortex?

Which disorder is caused by functional adrenocortical adenomas?

What is the primary treatment for adrenocortical carcinoma (ACC)?

Which tumour of the adrenal medulla is common in children?

How is pheochromocytoma typically diagnosed?

What is an adrenal incidentaloma?

What is the most effective treatment for adrenal carcinomas?

What recent diagnostic tool is being looked at for adrenal diseases?