TUMORS OF THE ADRENALS

Recent advances in imaging techniques (e,g, computed tomography, nucle ar resonance imaging) have led to the discovery of unexpected adrenal tumors in about 2% of the patients. The incidental discovery of an adr enal tumor presents a complex diagnostic problem since the differentia tion of the few endocrine active adrenal tumors (combined less than 6% of incidental adrenal tumors) and extremely rare adrenal carcinomas ( less than 0.07%) from the very frequent harmless adrenal lesions requi res a careful approach to avoid unnecessary diagnostic procedures and surgery. The initial investigations evaluate endocrine activity by cli nical signs of sex steroid and mineralocorticoid overproduction. When neither hypertension in combination with hypokalemia nor virilization/ feminization are present, costly hormone determinations can be omitted . The low-dose dexamethasone test and determination of 24-hour urinary free cortisol and catecholamines should always be performed. In case of positive screening results further confirmatory tests are needed, U sually all endocrine active tumors are surgically removed, as well as endocrine inactive masses larger than 5 cm because of suspected malign ancy. Endocrine inactive tumors even smaller than 5 cm have a 60% chan ge of being a metastasis if the patient has or has had a malignancy. I mage-guided fine-needle biopsy can distinguish metastases from adrenal tissue with high sensitivity and specificity, but is not indicated wh en primary adrenal carcinoma is suspected, since the differentiation o f benign from malignant primary adrenal tumors by cytology is of low a ccuracy. For tumors smaller than 5 cm exhibiting no criteria of malign ancy in the initial image, observation by follow-up CT scanning after 3 and 6 months is justified, If morphological criteria of malignancy a re present, functional scintigraphy with I-131 norcholesterol may give further support to adrenalectomy by showing reduced tracer uptake. Su rgical resection is the therapy of choice for primary adrenal carcinom as. However, at diagnosis 70% of patients present with metastases. Of these, 30% respond to high-dose mitotane therapy with partial remissio n. Other modalities have hardly been evaluated and so far not proven t o be of higher efficacy. Five-year survival rates are between 25 and 4 3%.