April is Adrenal Disease Awareness Month, and the Carling Adrenal Center is bringing you expert content on adrenal diseases all month long. In this article, we will discuss how pheochromocytoma is diagnosed.

How is pheochromocytoma diagnosed?

First things first, the diagnosis of pheochromocytoma hinges on the treating physician entertaining the diagnosis in the first place. We can't diagnose a pheochromocytoma if the doctor doesn't even think of it, and this is the number one reason that many pheochromocytomas do not get diagnosed. Every week we see patients who (in retrospect) have had their symptoms of a pheochromocytoma for years and decades before the tumor is diagnosed.

How is pheochromocytoma diagnosed: First, what is a pheochromocytoma?

Pheochromocytoma is a tumor that develops in the adrenal gland. It can cause a range of symptoms, including high blood pressure, headaches, and palpitations. If left untreated, pheochromocytoma can lead to serious health complications, including heart attack and stroke. Pheochromocytomas produce excess adrenaline (also referred to catecholamines; epinephrine, metanephrine, and dopamine). Pheochromocytomas arise from the central portion of the adrenal gland, which is called the adrenal medulla. The adrenal medulla is responsible for the normal production of adrenaline, which our body requires to help maintain blood pressure and to help cope with stressful situations. A tumor that arises from the adrenal medulla and overproduces adrenaline can be a deadly tumor.

Figure 1: Common symptoms of pheochromocytoma

How is pheochromocytoma diagnosed?

The diagnosis of pheochromocytoma is typically made by showing the amount of adrenaline and epinephrine-type hormones is higher than it should be in a patient's blood. Thus, the overproduction of these adrenaline-like hormones signifies that a tumor of the adrenal medulla is present, and thus the diagnosis of pheochromocytoma is made.

Figure 2. A typical left pheochromocytoma after it was removed by Dr. Carling. Pheochromocytomas are pale, pink-purple versus the normal adrenal cortex in orange.

How is pheochromocytoma diagnosed: What lab tests are needed?

Here are some of the most common methods used to diagnose pheochromocytoma:

• Blood and Urine Tests - Blood and urine tests are used to measure the levels of certain hormones in the body, such as adrenaline and epinephrine. High levels of these hormones can indicate the presence of a pheochromocytoma. Read more here: https://www.adrenal.com/pheochromocytoma/lab-testing

• Imaging Tests - Imaging tests, such as CT scans or MRIs can be used to visualize the adrenal gland and detect any potential tumors. Sometimes, these adrenal tumors are even found incidentally, meaning when examining an imaging test completed for another reason. Read more below and here: https://www.adrenal.com/pheochromocytoma/imaging-scans

• Genetic Testing - Pheochromocytoma can sometimes be caused by genetic mutations. Genetic testing can identify these mutations and help diagnose the condition. Additionally, almost 20 % of pheochromocytomas are hereditary (meaning they occur in families due to mutations in tumor-susceptibility genes). These patients and families should be screened for the pheochromocytomas. In some cases of hereditary pheochromocytomas, an individual with a certain gene mutation has a greater than 50% risk of developing a pheochromocytoma during their lifetime. Read more here: https://www.adrenal.com/blog/top-6-differences-between-pheochromocytoma-and-paraganglioma

• Glucose Test - Glucose intolerance may be present in up to 50% of pheochromocytoma patients. Pheochromocytoma can cause a condition called paroxysmal hypertension, which leads to sudden spikes in blood pressure. A glucose test can be performed to see if these spikes occur after the administration of glucose.
  
  

Early detection and treatment of pheochromocytoma is essential for preventing serious health complications. If you are experiencing any symptoms associated with pheochromocytoma, such as high blood pressure, headaches, or heart palpitations, it's important to seek an expert evaluation. Your doctor can perform the necessary tests to diagnose or rule out pheochromocytoma.

How is pheochromocytoma diagnosed: What does a pheochromocytoma look like on imaging (CT, MRI, PET) studies?

There are 3 main types of imaging studies used to localize and image pheochromocytomas:

• CT (CAT) scan
• MRI
• Nuclear medicine scan (MIBG, PET)

In >95% of cases all you need is a CT scan. The best CT scan is an adrenal-protocol CT scan which with and without contrast. If the CT scan shows an adrenal tumor and your adrenaline levels are high, you will need adrenal surgery for a likely pheochromocytoma.

Figure 3. A typical right pheochromocytoma on CT scan (yellow arrow). The white arrow indicates the normal left adrenal gland.

MRI and nuclear medicine scans have a role occasionally, and you can read more here: https://www.adrenal.com/pheochromocytoma/imaging-scans

Figure 4. A typical left pheochromocytoma on MRI and after it was removed

ALERT: Many doctors order one scan after another because they are inexperienced and do not know what to do. The temptation is to do something (order a scan…) then not doing anything, at all. Avoid this trap. If you have had a scan, which shows an adrenal tumor, contact us. Do not get another MRI and another PET scan. Chances are you do not need more scans. You need the tumor removed!

How is pheochromocytoma diagnosed: Who should be screened for a pheochromocytoma?

As stated, early detection of a pheochromocytoma is very important to avoid devastating health consequences such as heart attacks, heart failure and stroke. If you belong to any of the following individuals, you need to be screened (tested) to ensure you do not have a pheochromocytoma or paraganglioma.

• High blood pressure at a young age (< 50 years of age)
• High blood pressure with an adrenal incidentaloma
• High adrenaline “spells”. This may be very variable but include.
• Heart racing and pounding
• Pallor (face turning pale, then often followed by flushing)
• Tremor (shakiness)
• Headache
• Sweating
• Episodic symptoms, known as spells (usually 5-10 minutes)
• High blood pressure in a family with any family member with an adrenal tumor (pheochromocytoma)
• Resistant hypertension (i.e. poor response to medications)
• Hypertension requiring many medications.

• A familial syndrome that predisposes to catecholamine-secreting tumors (e.g., multiple endocrine neoplasia type 2, neurofibromatosis type 1, von Hippel- Lindau disease, familial pheochromocytoma & paraganglioma syndromes)

How to diagnose pheochromocytoma: I’ve been diagnosed, now what?

If you have been diagnosed with pheochromocytoma, adrenal surgery may be recommended to remove the tumor.

Adrenal surgery is considered the most effective treatment for pheochromocytoma. While medications can be used to control symptoms, the tumor will continue to grow and cause damage to the body unless it is removed.

The best adrenal operation for roughly 95% of pheochromocytomas (and thus, likely your pheochromocytoma) is the Mini-Back Scope Adrenalectomy (MBSA). 

Patients needing adrenal surgery travel from all over the world to have adrenal surgery with Dr. Carling, the most experienced adrenal surgeon in the world. Become Dr. Carling's patient.

Additional Resources: 

• Learn more about the Carling Adrenal Center
• Learn more about Dr. Tobias Carling
• Learn more about our sister surgeons at the Norman Parathyroid Center, Clayman Thyroid Center and Scarless Thyroid Surgery Center
• Learn more about the Hospital for Endocrine Surgery