Adrenal Incidentaloma

• • Incidence has increased with use of ultrasonography, CT, and MRI for various, nonrelated diseases of the abdomen

  • Diagnosis includes such conditions as nonfunctioning adrenocortical adenoma, functioning adenoma, pheochromocytomas with subclinical secretion of hormones, and adrenocortical carcinomas

  • Major issues to determine is whether the tumor is hormonally active or whether it is a carcinoma

Epidemiology

• • Found in 1-4% of CT scans

  • Found in 6% of random autopsies

  • Incidence increases with age

  • Over 80% are nonfunctioning cortical adenomas

  • 5% each are preclinical Cushing syndrome, pheochromocytoma, and adrenocortical carcinoma

  • 2% are metastatic carcinoma

  • 1% are aldosteronoma

  • 25% of pheochromocytomas are found incidentally

Symptoms and Signs

• • Asymptomatic; discovered on imaging study done for nonrelated disease process

Laboratory Findings

• • Depends on type of tumor; nonfunctional adenoma will have no laboratory abnormalities

Imaging Findings

• • Most pheochromocytomas are over 2 cm in diameter and characteristically bright on T2-weighted MRI

  • CT scan findings of heterogeneity or irregular borders are suspicious for malignancy

  • PET scans may be useful in detecting malignant lesions

• • Simple adrenal cysts, myelolipomas, and adrenal hemorrhages can be identified by the CT characteristics alone

  • Adrenal cysts can be very large but are very rarely malignant

  • Since most tumors are nonfunctioning adenomas, the work-up should avoid unnecessary procedures and expense

  • Nonfunctioning adrenal tumors that are greater than 5 cm have a high risk of cancer (up to 33%)

  • An adrenal mass > 3 cm in a patient with a previously treated malignancy is very likely a metastasis

  • Tumors that metastasize to the adrenal gland include: lung, breast, colon, hypernephroma, malignant melanoma, uterine, and prostate

• • Complete history and physical exam, with specific reference to previous malignancies, symptoms of Cushing syndrome, hypertension, virilization, or feminization

  • All patients, even those without hypertension, should have plasma metanephrines and/or 24-hour urinary fractionated catecholamines determined to evaluate for pheochromocytoma

  • All patients should have a serum cortisol, 24-hour urine collection for cortisol, and an overnight dexamethasone suppression test to assess for Cushing syndrome

  • Patients who are hypertensive should have serum potassium and plasma aldosterone and renin activity measured

  • Consider obtaining a dehydroepiandrosterone (DHEA) level (potential marker for adrenocortical carcinoma)

  • If above studies show the tumor to be nonfunctional, the size of the tumor and the patient's overall medical condition determine management

  • If metastasis is suspected and pheochromocytoma is ruled out, then CT-guided fine-needle aspiration can be useful

• • Management depends on functional status and size of the tumor

  • Metastatic adrenal lesions should be treated appropriately in concert with the underlying primary cancer

Surgery

Indications

• • Hormonally active tumor

  • Adrenocortical carcinoma

  • Consider for nonfunctional tumors > 4 ...