Adrenal carcinoma

Clinical About half of adrenal cortical neoplasms are hyperfunctioning, and the other half are nonhyperfunctioning. The hyperfunctioning, or hormone-producing tumors, are discussed later in this chapter. Many nonfunctioning tumors are discovered incidentally. Although nonfunctioning adenomas occur at all ages, the prevalence increases with age.A relationship appears to exist between an adenoma’s lipid content and its functional status. Adenomas are more common in diabetic and hypertensive patients. Both adenomas and carcinomas are more common in women and are detected at a younger age in women.
Both adrenal adenomas and carcinomas are more prevalent than usual in patients with Gardner’s syndrome. Patients with Li-Fraumeni syndrome have a predisposition to adrenocortical carcinomas; in this autosomal-dominant syndrome adrenal tumors tend to develop in children and young adults. Cortical carcinomas are rare aggressive tumors. Most have a poor prognosis even if resected. Adrenal cortical carcinomas in children tend to be very malignant and most are functional.
An interesting phenomenon consists of adrenal collision tumors. Thus a contiguous adrenal adenoma and metastasis results in the adenoma component displaying a signal loss on opposed-phase MR images and the metastatic component increasing in signal intensity.
At times neither a biopsy nor a resected specimen allows adequate evaluation of an adrenocortical tumor if only histologic criteria are employed; immunohistologic staining is often helpful. Nevertheless, even then the true nature of a tumor may not be apparent. For example, CT and US discovered an incidental homogeneous adrenal tumor in a 43-year-old woman; endocrine tests revealed preclinical Cushing’s syndrome. An adrenalectomy was performed, and histology revealed an adrenocorticaltumor of undetermined nature, 4 months later the patient presented with a metastatic cortisol and androgen-producing adrenocortical carcinoma.
Pain is more common with carcinomas. Precocious puberty develops in an occasional patient. About half of these tumors have some type of endocrine abnormality, but in general, endocrine testing per se does not differentiate between benign and malignant tumors. The role of percutaneous ablation for adrenal tumors is mostly anecdotal.
Imaging Regions of hemorrhage and necrosis are common in carcinomas and result in a heterogeneous appearance. Necrosis is not specific for a carcinoma and is also seen in adrenal hemangiomas and other larger tumors. Some adenomas and carcinomas develop calcification. Calcifications are more common in larger, heterogeneous-appearing tumors containing central necrosis or hemorrhage; the imaging appearance of these larger tumors does not permit ready differentiation between adenomas and carcinomas.
Especially with the larger adrenal carcinomas, the vena cava should be studied for possible invasion. A right adrenal gland adrenocortical carcinoma can grow as an intracaval tumor thrombus, at times even extending into the atrium. Or, a neoplasm invading the inferior vena cava results in an acute Budd-Chiari syndrome. Imaging, including magnetic resonance angiography (MRA), is useful in evaluating malignant tumor extension into the adrenal veins and inferior vena cava. A carcinoma tends to have patchy CT contrast enhancement, a somewhat nonspecific finding. Nonfunctioning adenomas are hypointense to liver on T1- and vary in intensity on T2- weighted MR images. Magnetic resonance is useful in distinguishing a cyst from an adenoma; on T2-weighted images fluid in a cyst is hyperintense.
image
Radiology images of the Adrenal carcinoma. Precontrast (A) and contrast-enhanced (B) magnetic resonance (MR) images reveal a large, heterogeneous
right adrenal tumor (arrows).
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