The key difference between paraganglioma and pheochromocytoma is that paraganglioma is an adrenal gland tumor that forms outside the adrenal gland, while pheochromocytoma is an adrenal gland tumor that forms in the center of the adrenal gland.
Paraganglioma and pheochromocytoma are two types of adrenal glands tumors. Adrenal gland tumors are cancerous or non-cancerous growths on the adrenal glands. The cause of most of these tumors is not known. The risk factors for adrenal tumors include Carey complex, Li-Fraumeni syndrome, multiple endocrine neoplasia type 2, and neurofibromatosis type 1.
CONTENTS
1. Overview and Key Difference
2. What is Paraganglioma
3. What is Pheochromocytoma
4. Similarities – Paraganglioma and Pheochromocytoma
5. Paraganglioma vs Pheochromocytoma in Tabular Form
6. Summary – Paraganglioma vs Pheochromocytoma
What is Paraganglioma?
Paraganglioma is an adrenal gland tumor that forms outside the adrenal gland. It is a type of neuroendocrine tumor that forms near certain blood vessels and nerves outside of the adrenal glands. Adrenal glands are located on the top of the kidneys. They perform a number of important roles, including making hormones that control many functions in the human body. The nerves affected in the case of paraganglioma are part of the peripheral nervous system. It means that these nerves are a part of the nervous system outside the brain and spinal cord. Moreover, approximately 35-50 % of paraganglioma can spread to other parts of the body.
Figure 01: Paraganglioma
The common symptoms of this tumor include high blood pressure, sweating, heart palpitation, bone pain, hearing loss, tinnitus, anxiety, and headache. About one in four paragangliomas are inherited. Defects in genes such as succinate dehydrogenase subunits B (SDHB), C (SDHC), and D (SDHD) are linked to familial paraganglioma. The mutation in the RET gene is also a genetic cause of paraganglioma.
Paraganglioma is diagnosed through urine tests, blood tests, CT-scans, MRIs, metaiodobenzylguanidine (MIBG) scans, PET scans, and genetic testing. Furthermore, the treatment options may include blood pressure medications (phenoxybenzamine, doxazosin, or propranolol), excess hormone production controlling medications (alpha-blockers, beta-blockers, calcium channel blockers), surgery, nuclear medicine treatments such as radioactive MIBG or octreotide, thermal ablation therapy, chemotherapy, and targeted drug therapy.
What is Pheochromocytoma?
Pheochromocytoma is an adrenal gland tumor that forms in the center of the adrenal gland. It is a rare tumor of the adrenal medulla composed of chromaffin cells (pheochromocytes). These neuroendocrine tumors are capable of producing and releasing a massive amount of catecholamines, metanephrines, and methoxytyramine. The symptoms of this condition may include headaches, hypertension, tachycardia, diaphoresis (excessive sweating, hyperhidrosis (night sweating), physical exertion, anxiety, panic attacks, trauma, pallor, heat intolerance, chest or abdominal discomfort, nausea, vomiting, constipation, and hyperglycemia. Hereditary pheochromocytoma can occur due to classic mutations of genes such as RET, VHL, and NF1. Other inherited gene mutations that can cause pheochromocytoma include MAX and TMEM127.
Figure 02: Pheochromocytoma
Pheochromocytoma can be diagnosed through a 24-hour urine test, blood test, imaging tests (CT-scan, MRI, MIBG scan, PET scan), or genetic testing. Furthermore, the treatment options may include alpha-blockers, beta-blockers to lower blood pressure, high salt diet (prevent dangerous blood pressure drops), surgery, MIBG radiation therapy, peptide receptor radiation therapy (PRRT), chemotherapy, radiation therapy, and targeted cancer therapy.
What are the Similarities Between Paraganglioma and Pheochromocytoma?
- Paraganglioma and pheochromocytoma are two types of adrenal gland tumors.
- Both tumors are rare and slow-growing tumors.
- 30-40% of both tumors are inherited.
- Both tumors are catecholamine-producing neuroendocrine tumors.
- They show common symptoms such as high blood pressure, sweating, and headaches.
- They have common risk factors such as multiple endocrine neoplasia type 2, Von Hipple-Lindau disease, and neurofibromatosis (NF1).
- They have similar diagnosis procedures.
- They can be treated through chemotherapy, radiation therapy, and specific surgeries.
What is the Difference Between Paraganglioma and Pheochromocytoma?
Paraganglioma is an adrenal gland tumor that forms outside the adrenal gland, while pheochromocytoma is an adrenal gland tumor that forms in the center of the adrenal gland. Thus, this is the key difference between paraganglioma and pheochromocytoma. Furthermore, paraganglioma can occur due to inherited mutations in genes such as SDHB, SDHC, and SDHD, while pheochromocytoma can be caused due to inherited mutations in genes such as RET, VHL, and NF1, MAX, and TMEM127.
The below infographic presents the differences between paraganglioma and pheochromocytoma in tabular form for side by side comparison.
Summary – Paraganglioma vs Pheochromocytoma
Paraganglioma and pheochromocytoma are two types of adrenal glands tumors. Both tumors are catecholamine-producing neuroendocrine tumors. Paraganglioma tumor develops outside the adrenal gland, while pheochromocytoma tumor develops in the center of the adrenal gland. So, this summarizes the difference between paraganglioma and pheochromocytoma
Reference:
1. “Paraganglioma.” National Cancer Institute.
2. “Pheochromocytoma.” Mayo Clinic, Mayo Foundation for Medical Education and Research.
Image Courtesy:
1. “Adrenal paraganglioma clinical Pheochromocytoma” By Michael Feldman, MD, PhDUniversity of Pennsylvania School of Medicine – Heal Central (CC BY 2.0) via Commons Wikimedia
2. “Adrenal Pheochromocytoma LP RBWH” By Sarahkayb – Own work (CC BY-SA 4.0) via Commons Wikimedia