Pheochromocytoma is a rare form of neuroendocrine tumor that usually develops in the adrenal gland, but can also arise in other parts of the body. Pheochromocytomas produce excess amounts of adrenalin and related hormones, which are the “fight-or-flight” hormones usually released by the adrenal glands in response to stress. These hormones can cause a person to have elevated blood pressure (hypertension) and an increased heart rate. Patients with pheochromocytomas often have unusually severe or unexplained hypertension. Pheochromocytomas are also sometimes diagnosed when a tumor on the adrenal gland is observed during CT scans or other imaging performed for unrelated medical conditions.
The hormones produced by pheochromocytoma cause high blood pressure, rapid heart rate, and, in some cases, heart damage. Often the hormone secretion is more dangerous than the tumor itself. Pheochromocytomas in some cases can metastasize like other cancers. Patients with a pheochromocytoma may experience intermittent headaches, heart palpitations, and sweating. The spells may vary in occurrence from monthly to several times per day, and the duration may vary from seconds to hours. Typically, the spells worsen with time, occurring more frequently and becoming more severe as the tumor grows.
Pheochromocytoma is a tricky disease to diagnose. Diagnostic techniques for pheochromocytoma include:
- Biochemical tests for hormones, including dopamine, metanephrines, and normetanephrines. Interpretation of the test results requires considerable experience, and both false negative and false positive results are common.
- Standard imaging with CT/MRI may help localize the tumor
- Imaging with MIBG or PET may also help identify the primary tumor and metastases.
- Biopsy of a pheochromocytoma can be dangerous, since this can precipitate hormonal symptoms. A decision to biopsy should only be made with the input of an experienced medical team.
Patients with pheochromocytoma often need to be treated medically prior to an attempt at surgery. Medical treatment may include control of hormonal symptoms with medication and intravenous hydration. Complete surgical removal of the tumor is usually the first goal. If a complete surgical removal is not possible then other treatment options are usually considered. These options may include:
- Surgical resection to reduce tumor bulk
- MIBG radiotherapy
- Experimental medications
- Supportive care for all patients