Nonfunctional adrenal masses are space-occupying lesions of the adrenal glands that have no hormonal activity. Symptoms, signs, and treatment depend on the nature and size of the mass.
(See also Overview of Adrenal Function.)
The most common nonfunctioning adrenal masses in adults are
Adenomas
Adenomas represent more than half of adrenal masses (1).
Other common nonfunctioning adrenal masses are
Carcinomas
Metastatic tumors
Cysts and lipomas make up most of the remainder. However, the precise proportions depend on the clinical presentation.
Masses discovered on incidental screening are usually adenomas. Less commonly, in neonates, spontaneous adrenal hemorrhage may cause large adrenal masses, simulating neuroblastoma or Wilms tumor. In adults, bilateral massive adrenal hemorrhage may result from thromboembolic disease or coagulopathy, whether disease- or medication-related.
Benign cysts are observed in adult patients and may be due to cystic degeneration or vascular accidents. Lymphomas, bacterial infections, fungal infections (eg, histoplasmosis), or parasitic infestations (eg, due to Echinococcus) may also manifest with adrenal masses, sometimes bilateral. Hematogenous spread of Mycobacterium tuberculosis may cause adrenal masses.
A nonfunctional adrenal carcinoma causes a diffuse and infiltrating retroperitoneal process. Hemorrhage can occur, causing adrenal hematomas.
Reference
1. Arnold DT, Reed JB, Burt K. Evaluation and management of the incidental adrenal mass. Proc (Bayl Univ Med Cent) 2003;16(1):7-12. doi:10.1080/08998280.2003.11927882
Symptoms and Signs of Nonfunctional Adrenal Masses
Most patients are asymptomatic. With any adrenal mass, adrenal insufficiency is rare unless both glands are involved. Hyperfunction occurs more frequently.
The major signs of bilateral massive adrenal hemorrhage are
Abdominal pain
Falling hematocrit
Signs of acute adrenal failure (eg, abdominal pain, loss of consciousness, fatigue, dehydration)
Suprarenal masses on CT or MRI
Tuberculosis of the adrenals may cause calcification and Addison disease. Nonfunctional adrenal carcinoma usually manifests as invasive or metastatic disease.
Diagnosis of Nonfunctional Adrenal Masses
Adrenal hormone measurements
Fine-needle biopsy
Nonfunctional adrenal masses are usually found incidentally during tests such as CT or MRI conducted for other reasons. Nonfunctionality is established clinically and confirmed by adrenal hormonal measurements.
Screening adrenal hormonal measurements include dexamethasone suppression testing and serum cortisol (to rule out Cushing syndrome), 24-hour urinary or plasma fractionated metanephrines (to rule out pheochromocytoma) and plasma aldosterone and renin (to rule out primary aldosteronism).
If metastatic or infectious disease is possible, fine-needle biopsy can be diagnostic but is contraindicated if there is suspicion of adrenal carcinoma (to avoid spread of tumor) or pheochromocytoma (to avoid precipitating acute hypertension).
Treatment of Nonfunctional Adrenal Masses
Sometimes excision, depending on size and/or imaging results
Periodic monitoring
Although some imaging modalities (eg, in-phase and out-of-phase MRI) may be diagnostic, if the tumor is solid, of adrenal origin, and > 4 cm, it should usually be excised unless the imaging characteristics are clearly benign.
Tumors 2 to 4 cm in diameter are a particularly difficult clinical problem. If scanning does not suggest cancer and hormonal function is not altered (eg, normal electrolytes and metanephrines, no evidence of Cushing syndrome), it is reasonable to reevaluate periodically with imaging studies, usually for 1 to 2 years. If no progression occurs by then, further follow-up is unnecessary. However, many of these tumors secrete cortisol in quantities too small to cause major symptoms, and whether they would eventually cause symptoms and morbidity if untreated is unclear. Most clinicians merely observe patients with these tumors, but clinicians should consider removal of these tumors if there is significant cortisol secretion.
Adrenal adenomas < 2 cm require no special treatment but should be observed regularly over a period of time (eg, about every 6 months for 2 years) for growth and for development of secretory function (such as by looking for clinical signs and periodically measuring electrolytes).
More Information
The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
