Adrenal Tumors

Abstract

When one thinks of adrenal tumors in children, neuroblastoma is usually the first consideration. However, there are several other neoplastic processes that can involve the adrenal gland in the pediatric population and run the gamut from aggressive malignancies with a very poor prognosis to benign processes with an excellent prognosis. They might be completely asymptomatic or express a broad variety of endocrine behaviors. Although heterogeneous by nature, they share the fact that surgery is the primary mode of therapy.

Appendices

Summary Points

Adrenal tumors are a heterogeneous group and can be benign or malignant, but for most surgery is the primary mode of therapy.

Adrenocortical carcinoma are very rare in children, accounting for less than 0.2% of all pediatric malignancies.

A significant number of patients with adrenocortical tumors have a p53 mutation.

Although adrenocortical carcinoma presents as an asymptomatic mass in about 10% of cases, it frequently presents with evidence of hormonal stimulation.

The absence of effective chemotherapy for adrenocortical carcinoma dictates aggressive attempts at resection.

Although pheochromocytomas are seen in association with hereditary syndromes including MEN-2A, MEN-2B, and NF-1, most tumors are sporadic.

Most pediatric patients with pheochromocytoma have signs and symptoms of sustained rather than paroxysmal hypertension.

The primary treatment for pheochromocytoma is surgical resection.

Editor’s Comment

Many of the adrenal masses encountered in children can be resected laparoscopically, including pheochromocytomas, most ganglioneuromas, and even some neuroblastomas. The size of the mass might be a limiting factor depending on the experience of the surgeon. Tumors for which spillage is potentially disastrous, such as adrenocortical carcinomas, should probably not be approached using a minimally invasive approach. In most cases, a lateral, transabdominal approach can be used for both right and left adrenal lesions. The majority of the operation can be performed using blunt dissection, dividing small vessels with the harmonic scalpel or hook electrocautery. Control of the adrenal vein can be particularly hazardous, especially on the right where it is typically very short and enters directly into the IVC. It is easily torn by overly aggressive dissection but once identified can be clipped near its origin and divided.

Newborns with incidentally identified adrenal masses have neuroblastoma or adrenal hemorrhage. These are difficult to differentiate but the distinction is usually irrelevant, because either lesion, if small, can be safely observed. Resection is rarely necessary but sometimes demanded by anxious parents. Careful surveillance with serial ultrasound appears to be safe, but should probably be done as part of a clinical trial.

Adrenal ganglioneuromas are often found incidentally in teenagers who undergo CT or MRI for unrelated symptoms or as part of a trauma evaluation. The vast majority of these lesions are benign and could theoretically be safely observed indefinitely, however because a very small percentage of these will turn out to harbor a tiny neuroblastoma (ganglioneuroblastoma) resection is usually recommended. In fact, although most “incidentalomas” in children are benign, size and imaging characteristics do not necessarily predict the likelihood of malignancy. In practice then, a pediatric surgeon is asked to resect almost every adrenal mass identified in a child beyond the newborn period. Fortunately, these lesions can almost always be removed laparoscopically.

All but the smallest adrenocortical carcinomas should be resected using an open approach through a generous incision in order to make every effort to avoid breach of the capsule and even the slightest degree of tumor spillage. These tumors are generally unresponsive to chemotherapy and therefore complete resection offers the greatest (and sometimes only) chance for cure. Spillage upstages the tumor and can significantly diminish survival. The tumor capsule is often very delicate and tears easily. A meticulous and very gentle approach is imperative. Locally invasive tumors should be resected en bloc, including portions of adjacent spleen, liver, stomach or diaphragm if necessary to achieve negative margins. All patients should undergo an extensive ipsilateral retroperitoneal lymph node dissection for staging purposes. Unlike the case with Wilms tumor, adrenocortical carcinoma with tumor thrombus extension into the IVC or atrium almost never shrinks in response to neoadjuvant chemotherapy. If, even after complete mobilization of the primary tumor, the thrombus cannot be pulled down into the infrahepatic IVC to allow placement of a vascular clamp above it, cavotomy on cardiopulmonary bypass must be used.

Diagnostic Studies

For Adrenocortical Tumors

• CT or MRI

• Urine for 17-ketosteroids and DHEA-S

• Serum for cortisol, DHEA-S, testosterone, renin activity, deoxycortisol, 17-hydroxyprogesterone, aldosterone, adrostenedione

For Pheochromocytoma

• CT or MRI

• MIBG scan

• Twenty-four hour urine for catecholamines, metanephrines, VMA, and HVA

Parental Preparation

There is a risk of bleeding and, for adrenocortical carcinoma, tumor spillage, and, for phechromocytoma, hypertensive crisis.

Preoperative Preparation

Careful surgical planning with 3-dimensional radiographic imaging.

Alpha and beta blockade for pheochromocytoma.

For adrenocortical tumors that extend into the retrohepatic IVC or atrium, arrangements for cardiopulmonary bypass or cardiac surgery on standby.