Sunday August 12, 2012
Need more awareness
A TUMOUR is defined as a swelling, and one of the cardinal signs of inflammation.
However, not all tumours are created equal, and not all tumours necessarily mean bad news.
Some are benign and do not pose any danger to health, except possibly for where they are growing in the body, as it could potentially prove harmful if they cause any blockage or press against other organs.
Paragangliomas are rare tumours that form near the carotid artery, along nerve pathways in the head and neck, and other parts of the body. Some paragangliomas make extra catecholamines called adrenaline and noradrenaline.
The release of these extra catecholamines into the blood may cause symptoms of disease.
Some tumours do not cause any symptoms, and are only discovered when a lump forms in the neck or when a procedure is carried out for another reason.
Symptoms of pheochromocytoma and paraganglioma occur when too much adrenaline or noradrenaline is released into the blood. These, and other symptoms, may be caused by the growth of pheochromocytomas and paragangliomas. (cancer.gov/cancertopics/pdq/treatment/pheochromocytoma/Patient)
According to consultant vascular surgeon Dr Leong Yew Pung, pheochromocytomas and extra-adrenal paragangliomas are rare tumours arising from neural crest tissue that develops into sympathetic and parasympathetic paraganglia throughout the body.
Sympathetic paraganglia include the adrenal medulla (pheochromocytomas), the organ of Zuckerkandl near the aortic bifurcation, and other paraganglia along the distribution of the sympathetic nervous system.
Parasympathetic paraganglia include the carotid body and other paraganglia along the cervical and thoracic branches of the vagus and glossopharyngeal nerves.
“The most recent World Health Organi-zation classification utilises the term pheochromocytoma exclusively for tumours arising from the adrenal medulla, and the term extra-adrenal paraganglioma for similar tumours that arise from other locations. It is a very rare tumour and the actual incidence is not documented.
“We would see perhaps at most, two cases a year. Except for carotid body tumours, bilateral tumours are rare. Multiple tumours are also rare. Of all pheochromocytomas and extra-adrenal paragangliomas, 25% occur in the setting of a hereditary syndrome,” explains Dr Leong.
“The presentation is usually a mass or swelling, or incidental on a chest X-ray, CT scan or MRI. The hormone-secreting tumours, pheochromocytomas, may present with hypertension or other signs of excessive sympathetic activities.”
Preliminary investigations for the condition include blood and urine tests to exclude hormone-secreting tumours, and CT/MRI/angiogram to localise the tumour and plan for the ensuing surgery.
The normal course of treatment would be surgical excision, and perhaps pre-operative embolisation to reduce intra-op bleeding.
“Tumours which are diagnosed early/small are usually easily excised without much complication. It becomes complicated, and the operation more difficult, when the tumour grows large and is situated in a ‘difficult area’.”
Recurrence, says Dr Leong, is rare, and probably happens only when the resection is not complete.
“Personally, I have only come across one case. Malignant changes are also very rare, and occur when the tumour is large and left untreated.”
One of the most challenging cases in his experience was a patient who had multiple paragangliomas. One of the tumours was very large, located in a difficult area (high in the neck, just below the base of the skull).
“As a vascular surgeon, the most common paraganglioma we see will be carotid body tumours, followed by others in the neck area close to the artery. Those in the chest, abdomen and skull are usually seen by the respective surgeons.
“The location is more important as it is more difficult to remove in certain areas, such as high in the neck near the base of the skull. The number of tumours is not important if they are easily resected. Multiple tumours are uncommon.”
Consultant vascular surgeon Dr R. Vijeyasin-gam is of the opinion that up to 50% of paragangliomas cases are hereditary, bearing specific genetic and gene deficiencies.
“Usually, we categorise paragangliomas into carotid and non-carotid tumours. Surgery may be complicated, especially if it is located in the neck area, as there is a 10 to 12% risk of stroke.
“Here’s an indication of how rare the condition is: even the well-known Mayo Clinic (based in Rochester, Minnesota, specialising in treating difficult cases) has seen only 12 cases in the last 10 years. In my 14 years of experience (as a vascular surgeon) in a private hospital, I’ve treated all of 12 cases,” he says.
Usually, if the patient is younger, then surgery would be the recommended course of action. However, if the patient is older, say in his/her 50s, radiosurgery may be a better option.
“If the tumour is located near the adrenal gland, then it could be challenging, and you run a risk of the blood pressure dipping or rising suddenly during surgery.
“There is a very real element of fear when surgery is involved. And the longer a tumour is left untreated, the higher the chances that it may become malignant when it grows larger.
“A patient came to see me with a carotid tumour a few years ago, and I had scheduled surgery. However, she was so fearful of the consquences of surgery that she kept putting it off. Today, the tumour has grown so large that I can no longer do anything for her surgically,” he explains.
“The discovery of the condition is often incidental, and misdiagnosis is not uncommon as paraganglioma is so rare. Patients (and doctors) should pay more attention to neck swellings and not rule it out. It’s also a bit of a dilemma here as we only have 14 vascular surgeons in Malaysia, and most of us are in the Klang Valley,” says Dr Vijeyasingam, adding that, “Awareness of vascular disease is very poor.” – Patsy Kam