Benign neoplasm emerging from the cells of the adrenal cortex

Aetiology

• Found in almost all age groups but increase in frequency with age

Pathophysiology

• Majority (~95%) are non-functioning and asymptomatic
• Well circumscribed, encapsulated lesions
• Solitary, small (2 to 3 cm), bright yellow (lipid) and buried within the gland - do not cause a mass lesion

Histological features

• Composed of cells resembling adrenocortical cells
• Well-differentiated, small nuclei

Clinical features

• Often incidental finding during abdominal imaging
• Patients with hyperfunctioning adrenal gland adenomas present with manifestations of excess hormone secretion e.g. Cushing's, Conn syndrome

Investigations

• Imaging (CT, MRI)
• Hormonal testing

Management

• A small adrenal lesion with typical features of an adenoma and without biochemical abnormality can be safely left in situ
• Surgical excision required if:
  • Functioning lesion
  • Large lesion (>3-5 cm) as considered potentially malignant