Adrenal Tumor
Adrenal tumors are often discovered incidentally on a CT scan or MRI of abdomen and require further evaluation.
Diagnostic Evaluation of an Adrenal Tumor
In the diagnostic evalution of an adrenal tumor, one has to answer the following two questions:
1- Is the tumor producing a hormone?
2- Is the tumor benign or malignant?
Is the tumor producing a hormone?
The adrenal tumor may produce one of the following hormones.
1- Cortisol
2- Aldosterone
3- Catecholamines
Excess cortisol production can give rise to clinical signs and symptoms of Cushing's Syndrome.
Excess aldosterone production can give rise to clinical signs and symptoms of aldosteronism.
Excess production of catecholamines can give rise to clincal signs and symtoms of Pheochromocytoma.
Diagnostic testing to detect excess hormone production
1- To detect excess production of cortisol:
Three tests are available:
- Overnight 1 mg Dexamethasoone Suppression Test.
- 24-hour urine for free cortisol.
- Midnight salivary cortisol.
Overnight 1 mg Dexamethasone Suppression Test is a good test to rule out any excess production of cortisol.
2- To detect excess production of aldosterone:
Two tests are available:
- Serum Potassium and 24-hour urine potassium and aldosterone.
- Plasma Renin Activity and Plasma aldosterone.
3- To detect excess production of catecholamines:
Two tests are available:
- 24-hour urine for free catecholamines, metanephrines and normetanephrines.
- Plasma free catecholamines.
Diagnostic testing for malignancy
The size of the tumor is a good indicator whether a tumor is benign or malignant.
Tumors less than 4.0 cm in size are generally benign. Tumors more than 4.0 cm carry a high risk for malignancy and therefore, need further evaluation, usually by a CT-guided needle biopsy.
Caution: Make sure that a tumor is not a catecholamine producing tumor before doing any biopsy or any other invasive procedure, because it can lead to a catastrophic event if it is a catecholamine producing tumor.
This article was written by Sarfraz Zaidi, MD, FACE. Dr. Zaidi
specializes in Diabetes,
Endocrinology
and Metabolism.
Dr. Zaidi is an assistant Clinical Professor of Medicine at UCLA and Director of the Jamila Diabetes and Endocrine Medical Center in Thousand Oaks, California.
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