The essence in brief:
Modern imaging techniques detect adrenal enlargements (incidentalomas) in about 3% of adults.
The approach depends on the size and endocrine activity of the incidentaloma.
Most incidentalomas are benign and can be observed, but larger ones have a higher risk of malignancy.
Diagnostic evaluation includes clinical examination, hormonal testing, and imaging studies (CT, MRI, PET-CT).
Treatment is based on the presence of hormonal activity and malignancy. Hormonally active or malignant tumors should be surgically removed.
Surgical procedures can be open adrenalectomy for suspected malignancy or laparoscopic adrenalectomy for smaller tumors without local invasion.
Endocrinologically inactive benign tumors may not require further treatment.
Regular follow-up is essential to monitor changes in incidentalomas.
With modern imaging techniques such as ultrasound, computed tomography (CT), and MRI, adrenal enlargements are detected in approximately 3% of adults during these examinations. The prevalence is age-dependent and can be as high as 10% in 80-year-olds. These incidentally discovered adrenal enlargements are referred to as incidentalomas. The approach primarily depends on the size of the incidentaloma and whether it exhibits endocrine activity. Most incidentalomas are benign and can be observed. As the size increases, the risk of malignancy rises. Only 2% of tumors smaller than 4 cm are adrenal carcinomas. In the case of an incidentaloma larger than 6 cm, the risk increases to 25%.
Diagnostic Evaluation
Assessment of functional activity.
The first step is a clinical examination to identify signs of hormonal activity in the incidentaloma. The clinical features of a functionally active tumor are described in the chapters on Cushing’s adenoma, pheochromocytoma, and Conn’s syndrome.
Hormonal Testing
1 mg dexamethasone suppression test
Metanephrines (in plasma or 24-hour urine)
Aldosterone-renin ratio (only in patients with hypertension and/or hypokalemia)
Sexual hormones and steroid precursors (in cases of suspected adrenal carcinoma)
Imaging Studies
Robust data is provided only by native CT. If the incidentaloma is homogeneous, and the Hounsfield Units are < 10, it can be assumed to be a benign process. No further imaging is necessary for a lesion < 4 cm. Hounsfield Units describe the attenuation of X-rays in tissue, allowing for the detection of pathological deviations.
A clear assignment is not possible with Hounsfield Units > 10.
Depending on the clinical situation, the following approaches can be taken:
Additional imaging with contrast-enhanced CT after 15 minutes
MRI with chemical shift analysis
Combination of PET and CT
Follow-up examinations are recommended after six months.
Depending on the clinical situation, immediate surgery may also be considered.
Treatment
Incidentalomas with increased autonomous cortisol secretion and clinically evident hormone production or malignant tumors should be surgically removed.
For tumors of unclear malignancy, additional imaging, observation with follow-up imaging, or surgery may be considered based on individual circumstances.
For endocrinologically inactive benign tumors, no further diagnostic evaluation is necessary.
Surgical Procedures:
In cases of radiological suspicion of malignancy and evidence of local tumor invasion, an open adrenalectomy is recommended.
If the tumor is smaller than 6 cm and shows no signs of local invasion, a laparoscopic adrenalectomy may be performed.
Hormonally Active Adrenal Tumors (Incidentalomas) are decribed in seperate sections:
Cushing Adenoma,