Peter Angelos, MD, PhD

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.

The management of well-differentiated thyroid cancer requires a multidisciplinary approach. The majority of patients are diagnosed only after a nodule is palpable. A cytologic evaluation can readily diagnose a papillary thyroid carcinoma but a follicular carcinoma requires determination of capsular or vascular invasion.

This article is the last in a series focusing on ethical issues in cancer care, prepared by researchers at Northwestern University. The articles highlight selected ethical issues, place the issues in the context of relevant literature, and comment on their significance in oncology practice. These issues are discussed in greater depth in Ethical Issues in Cancer Care (Kluwer, 1999).

Of the 1,870 ongoing cancer clinical trials in the world, 531 are phase I clinical trials designed to verify the safety of experimental cancer treatments and procedures for use in humans.[1]

Physicians who diagnose and treat cancer have an enormous responsibility. They not only have to be aware of the medical aspects of cancer screening, diagnosis, and treatment, but also have the difficult task of talking about these issues with their patients.