Cord Sturgeon, MD

Pheochromocytomas are tumors of the neural crest-derived chromaffin cells. The hallmark of this rare and fascinating neoplasm is the synthesis and secretion of catecholamines in an unregulated and potentially life-threatening manner. Most pheochromocytomas produce an abundance of norepinephrine. Epinephrine- or dopamine-secreting pheochromocytomas are less common.[1] Pheochromocytomas can also be nonfunctional.[1] Approximately 10% of pheochromocytomas can be categorized as either bilateral, multifocal, extra-adrenal, familial, or malignant; thus, pheochromocytomas are often remembered by medical students as the "10% tumor." Newer reports, however, suggest that pheochromocytomas may be extra-adrenal in up to 30% of cases.[2,3] This brief review will address the diagnosis and management of benign and malignant pheochromocytoma.

In part 2, we address risk assessment and staging, findings that suggest the presence of aggressive tumors, recurrent/metastatic disease, and treatment with chemotherapy and external-beam radiotherapy. Experimental treatments utilizing molecular targets, redifferentiation agents, and gene therapy are covered briefly as well.

Part 1 of this two-part article describes in detail the distinct types of thyroid cancer, as well as risk factors, outcomes, and prognostic factors, with a focus on thyroid cancers of follicular cell origin.