Published: 18 Jun 2025

ICD9: 255.6      ICD10: E27.5      ICD11: 2D11.1

Pheochromocytoma (PHEO) is a rare tumor that develops in the adrenal glands.
These glands are located on top of the kidneys and produce hormones that regulate various bodily functions, including blood pressure, heart rate, and metabolism.

Here's a breakdown:

What is it?

Tumor: A growth of abnormal cells.
Adrenal Glands: Small, hormone-producing glands on top of the kidneys.
Catecholamines: Pheochromocytomas produce excessive amounts of hormones called catecholamines. These include:
Epinephrine (Adrenaline): Increases heart rate, blood pressure, and energy.
Norepinephrine (Noradrenaline): Constricts blood vessels, increasing blood pressure.
Dopamine: Affects mood, motivation, and movement.

What does it do?

The excessive release of catecholamines causes:

Hypertension (High Blood Pressure): Often sudden and severe, known as paroxysmal hypertension.
Other Symptoms: The surges of hormones can lead to a variety of symptoms, which can be unpredictable and come and go.

Symptoms:

The classic symptoms of pheochromocytoma are episodic and can include:

High blood pressure (often sudden and severe)
Rapid heartbeat (palpitations)
Severe headache
Excessive sweating
Anxiety or panic attacks
Tremors
Pale skin
Shortness of breath
Abdominal pain
Constipation
Weight loss

Causes:

Genetic Factors: Many cases are related to inherited gene mutations. These mutations can be associated with syndromes like:
Multiple Endocrine Neoplasia type 2 (MEN2)
Von Hippel-Lindau (VHL) disease
Neurofibromatosis type 1 (NF1)
Spontaneous Mutation: Some cases occur randomly with no known family history.

Diagnosis:

Blood and Urine Tests: To measure levels of catecholamines and their breakdown products (metanephrines).
Imaging Scans: CT scans, MRI, or specialized nuclear medicine scans (like MIBG) to locate the tumor.
Genetic Testing: To identify inherited gene mutations.

Treatment:

The primary treatment is surgical removal of the tumor. Before surgery, patients need to be carefully managed with medications to control their blood pressure and heart rate. This is crucial to prevent dangerous complications during the procedure.

Alpha-Blockers: Medications that relax the blood vessels to lower blood pressure. These are almost always started first.
Beta-Blockers: Medications to slow the heart rate. These are typically started *after* alpha-blockers.
Surgery: Usually laparoscopic (minimally invasive) removal of the adrenal gland containing the tumor.
Other Treatments: If the tumor is cancerous (malignant) or has spread (metastasized), radiation therapy, chemotherapy, or targeted therapies may be used.

Importance of Diagnosis and Treatment:

It's crucial to diagnose and treat pheochromocytoma because:

Uncontrolled high blood pressure can lead to serious complications: Stroke, heart attack, kidney failure, and even death.
Surgery is often curative: Removing the tumor typically resolves the symptoms and normalizes blood pressure.

Paraganglioma

It is important to note that a related condition called a *paraganglioma* is very similar. These tumors occur outside the adrenal glands in specialized nerve cells. They often produce the same hormones and cause similar symptoms. The diagnosis, management, and treatment are very similar to pheochromocytomas.

In summary, pheochromocytoma is a rare but serious tumor of the adrenal glands that can cause life-threatening high blood pressure and other symptoms. Accurate diagnosis and timely treatment are essential. If you experience symptoms suggestive of a pheochromocytoma, consult a doctor immediately.