Nearly 10-15% of paragangliomas are asymptomatic(1).
Delay in diagnosis can cause severe cardiac complications and may even lead to sudden death(1).
Is Paraganglioma A Serious Condition?
Paragangliomas can be asymptomatic as well as symptomatic; asymptomatic ranging from 10-15% that can be diagnosed incidentally through imaging done for other causes or in postmortem cases. The symptoms of paragangliomas can be highly varied owing to the production of different catecholamines (epinephrine, norepinephrine, and dopamine) secretion, non-secretion of catecholamines by HNPGLs, location of the tumor mass, the involvement of other organs when associated with other hereditary syndromes and long-term exposure to high levels of circulating catecholamines(1).
Hypertension in advanced cases of PCCs and sPGLs is either seen as prolonged or paroxysmal. The classical triad of symptoms, namely, spells of palpitations, headaches, and diaphoresis (excessive sweating) along with hypertension are noted. If these symptoms are present then paraganglioma should be suspected and biochemical testing should be carried out. These paroxysms can last from few minutes to hours or even days and the frequency also varies. These spells can either occur spontaneously or be triggered through some activity, diagnostic procedures, certain foods (caffeine, amine-containing foods, certain cheeses), drugs (metoclopramide, glucocorticoids, glucagon).
Other associated symptoms include weakness, nausea, vomiting, anxiety, and hyperglycemia. Due to the atypical nature of the tumor, there can be a delay in diagnosis and this might lead to serious cardiac complications, such as myocardial infarction, arrhythmias, heart failure, cerebrovascular accidents, and even sudden death. Therefore, an immediate diagnosis is necessary. Head and neck paragangliomas can present with painless mass, hearing loss, difficulty in swallowing and speech, tinnitus, cranial nerve palsy, and hoarseness of voice(1).
Can Paragangliomas Be Reversed?
The diagnosis of paragangliomas can be done with biochemical testing by measuring the plasma levels of metanephrines and/or 24-hour urine excretion of fractioned metanephrines. Positive biochemical testing can be confirmed by imaging, including MRI, CT scan, MIBG (I-metaiodobenzylguanidine) scintigraphy, and PET scan(1).
Since most of the paragangliomas are benign, the condition can be reversed by surgically excising the tumor mass and the patients can be symptom-free and lead a normal life. Benign paragangliomas are also associated with an excellent prognosis. There are minor postoperative complications including hypotension and hypoglycemia, which can be well managed and subside in a few days. Regular annual follow-up with biochemical testing and blood pressure control is necessary to monitor patients for the possibility of a local recurrence or metastases. However, 10% of pheochromocytomas and 10-20% of paragangliomas are malignant and their management is a little bit tricky. Malignant tumors are managed by surgical resection of the primary tumor and the regional lymph nodes. Radiation therapy is also given to slow down the progression of the remaining disease. Combination chemotherapy (cyclophosphamide, vincristine, and dacarbazine) is also used in MIBG-negative patients.
These patients can be managed palliatively with conventional radiotherapy, arterial embolization, and chemoembolization for painful bone metastases and radiofrequency ablation for liver metastases. Catecholamine synthesis inhibitors can be used to reduce the signs and symptoms related to excess catecholamine secretions. Their prognosis is also poor with a 5-year survival rate of around 20-50%(1).
Paraganglioma is a rare neuroendocrine tumor arising from the neural crest cells along with the autonomic nervous system (sympathetic and parasympathetic nervous system). The associated sympathetic paragangliomas of the adrenal glands are known as pheochromocytomas (PCCs); whereas, outside the adrenal glands they are known as sympathetic paragangliomas (sPGLs). The parasympathetic type paragangliomas are more common in the head and neck region; therefore, they are termed as head and neck paragangliomas (HNPGLs).
Generally, people of all age groups are affected, but the greatest incidence is seen in individuals of 40-50 age groups. It equally affects the male and female population(1).
Although most of the paragangliomas are sporadic, one-third of tumors are hereditary and associated with hereditary syndromes. Generally, most of the paragangliomas are benign tumors; about 10-15% can be malignant that spread to distant sites devoid of chromaffin tissue, such as bone, lungs, liver, and lymph nodes(1).