Familial pheochromocytomas

Diagnostic imaging of the thyroid and adrenal glands in childhood

This article reviews the clinical utility of modern imaging techniques, particularly ultrasound (US), CT, and MRI in children with disorders of the thyroid and adrenal glands. Radionuclide scanning is the modality of choice in making the anatomic diagnosis in neonates with congenital hypothyroidism, while US is most useful in defining nodular thyroid disease. CT and MRI of the thyroid tend to be limited to defining the extent of thyroid carcinoma. Adrenal US is an essential step in the differential diagnosis of ambiguous genitalia or salt-losing crises in the newborn, while CT and MRI are more useful in defining the anatomy of the adrenals in older children with tumors or diffuse hyperplasia of the glands.

von Recklinghausen's disease and pheochromocytomas

PURPOSE

We review the literature and characterize the clinical findings of von Recklinghausen's associated pheochromocytoma.

MATERIALS AND METHODS

A Grateful Med search for the years 1966 to 1999 was performed on the subjects, "von Recklinghausen" and "neurofibromatosis." Articles from the Grateful Med search were then reviewed to identify older publications. Of 325 articles 118 are included in this review.

RESULTS

Pheochromocytomas have been clinically identified in 0.1 to 5.7% of patients with von Recklinghausen's disease. Mean patient age was 42 years (range 1.5 to 74) in 87 women and 61 men at presentation with pheochromocytoma. Of the 148 patients 84% had solitary adrenal tumors, 9.6% bilateral adrenal disease and 6.1% ectopic pheochromocytomas. Symptoms related to pheochromocytoma or hypertension were noted in 78% of the patients. Tumors secreted epinephrine and norepinephrine, and 87% demonstrated metaiodobenzylguanidine uptake. Of the 148 patients 6% died during pregnancy or a medical procedure, or due to hypertensive crisis without apparent provocation, 8.8% had gastrointestinal carcinoid tumors and 11.5% had metastases or local invasion from pheochromocytoma.

CONCLUSIONS

Pheochromocytomas occur in a small but defined number of patients with von Recklinghausen's disease, and can be associated with significant morbidity and mortality if not detected. Screening of patients with von Recklinghausen's disease and hypertension or before provocative procedures or pregnancy seems to be indicated.

Childhood familial pheochromocytoma. Conflicting results of localization techniques

Childhood familial pheochromocytoma was investigated in four patients by abdominal computed tomographic scan, [131I]metaiodobenzylguanidine scan, and vena caval catecholamine sampling. Results conflicted with surgical findings. Computed tomographic scan identified all four adrenal tumors but missed two midline tumors in one patient. [131I]metaiodobenzylguanidine scan identified two of three adrenal tumors but also suggested extra-adrenal tumors not confirmed at operation in two of three patients. Vena caval sampling for catecholamines confirmed all adrenal tumors but suggested additional tumors not verified at operation in two of three patients. All patients are asymptomatic and have normal urinary catecholamines 15 to 51 months after operation. Because of the frequency of multiple tumors in familial pheochromocytoma, different diagnostic techniques were employed. False-positive results were more frequent with [131I]metaiodobenzylguanidine and vena caval sampling. Reinterpretation of the [131I]metaiodobenzylguanidine scans at a later date led to less false-positive interpretation, although the false-negative rate remained unchanged. More pediatric experience with [131I]metaiodobenzylguanidine scans and vena caval sampling in familial pheochromocytoma is needed. Confirmation of tumor and its localization rest with meticulous surgical exploration.