PhaeochromocytomaAmira Zulaikha 082012100065

Nur Amalina 082012100067

• Greek "phaios =dark, chroma = color, kytos =cell, oma = tumor“

• Adrenal medulla secrete catecholamine• Catecholamines are :

o Epinephrineo Norepinephrine o Dopamine

Phaeochromocytoma• Rare neuroendocrine tumours of chromaffin tissue

that secrete catecholamines• Usually benign and contain large amounts of

epinephrine and norepinephrine• Responsible for less than 0.1% of hypertension

cases • 80% of these tumours occur in adrenal medulla

(phaeochromocytoma)• 20% in the body in sympathetic ganglia

(paragangliomas)

• 25% of phaechromocytoma are associated with inherited disorder. Examples are

• NeurofibromatosisoMultiple tumors develop from neurilemnal sheath

of nerves• Von Hippel-Lindau Syndrome

omutation in the von Hippel–Lindau tumor suppressor gene on chromosome 3

• MEN(Multiple Endocrine Neoplasia) type 2o Formation of adenomas in multiple glands

Clinical feature • Hypertension(usually paroxysmal)BP unto

300/200mmHg• Paroxysms of – Pallor– Palpitations– Sweating– Headache– Anxiety

• Abdominal pain, vomiting• Constipation• Weight loss• Glucose intolerence• Increased body temperature and BMR

Clinical TestEstimation of Urinary Excretion of Catecholamines &

their Metabolites ( metanephrine, normetanephrine, dopamine, and vanillylmandelic

acid (VMA) )

• the best method is using a 24-hour urine collection. • inconvenient but reliable and specific. • performed more than once to establish diagnostic

certainty.• Total urine catecholamines: 14 - 110 mcg/24 hours• Positive = catecholamine levels exceed double the

upper limit of normal.

Imaging tests and scans• only be performed after the diagnosis of

phaeochromocytoma has been established with 24-hour urine testing.

• Several types of scans can be used to locate pheochromocytomas. – Cross-sectional scans ( yield detailed anatomic

information)– Computed tomography (CT or CAT scan)– Magnetic resonance imaging (MRI)

Management• TREATMENT: surgical removal of tumour• pheochromocytoma patients experience

shock (dangerously low blood pressure) when catecholamine levels suddenly and unpredictably drop.

• medical therapy is needed to prepare patient for surgery

• Alpha –blocker render the body less sensitive to catecholmine surges

• Drugs used are:o alpha-blocker phenoxybenzamine (Non

competitive antagonist )o Prazosin o Doxasin

Reference

• Nicki R.Colledge, Brian R.Walker and Stuart H.Ralston,Davidson’s Principle and Practice of Medicine, 21st edition,Churchill Livingstone,2010, page 779

• Prof. A.K. Jain, Textbook of Physiology volume 2, 3rd edition,Avichal Publishing Company, 2007, page 757