|Year : 2016 | Volume
| Issue : 4 | Page : 288-290
Paraganglioma - The pharmacological time bomb
M Suresh Babu, PK Kiran, Karteek RN Udupa
Department of Medicine, JSS Medical College and Hospital, JSS University, Mysore, Karnataka, India
|Date of Web Publication||15-Nov-2016|
Dr. M Suresh Babu
Department of Medicine, JSS Medical College and Hospital, JSS University, Mysore, Karnataka
Source of Support: None, Conflict of Interest: None
Paragangliomas are rare neuroendocrine tumors that arise from the extra-adrenal autonomic paraganglia. Most paragangliomas are either asymptomatic or present as a painless mass. While all contain neurosecretory granules, only in 1%-3% of cases is secretion of hormones such as catecholamines abundant enough to be clinically significant with manifestations often resembling those of pheochromocytoma. Paragangliomas should be considered in the differential diagnosis in a patient presenting with an episodic headache and hypertension. New-onset hyperglycemia or worsening of preexisting diabetes may be the presenting feature in some patients with paragangliomas.
Keywords: Hypertension, neuroendocrine tumor, paraganglioma
|How to cite this article:|
Babu M S, Kiran P K, Udupa KR. Paraganglioma - The pharmacological time bomb. Int J Health Allied Sci 2016;5:288-90
| Introduction|| |
Paragangliomas are rare neuroendocrine tumors that arise from the extra-adrenal autonomic paraganglia, small organs consisting mainly of neuroendocrine cells that are derived from the embryonic neural crest and have the ability to secrete catecholamines. Paragangliomas are closely related to pheochromocytomas (which are sometimes referred to as intra-adrenal paragangliomas) and are indistinguishable at the cellular level. Sympathetic paragangliomas usually secrete catecholamines and are located in the sympathetic paravertebral ganglia of thorax, abdomen, and pelvis. In contrast, most parasympathetic paragangliomas are nonfunctional and located along the glossopharyngeal and vagal nerves in the neck and at the base of the skull. Catecholamine-secreting paragangliomas often present clinically such as pheochromocytomas with hypertension (HTN), episodic headache, sweating, and tachycardia. Catecholamine-secreting tumors are rare neoplasms, occurring in <0.2% of patients with HTN.
| Case Report|| |
A 32-year-old female patient presented to the emergency medicine department with a history of severe vomiting, blurring of vision, excessive sweating of 1-day duration. History of occasional headaches which was getting relieved on taking analgesics was present since 3 years. The patient was a known type 2 diabetes mellitus (DM) on treatment with an oral hypoglycemic agent and insulin (30 U) since last 7 years. The patient was not a known case of HTN/ischemic heart disease/chronic kidney disease. The patient had a history of 4 abortions (G5A4L1) and had delivered a live healthy baby 1 year back under lower segment caesarean section. The patient was diagnosed with gestational DM in her second pregnancy. There was no history of pregnancy-induced hypertension. The patient had been previously worked up for Antiphosphplipid antibody (APLA) in view of multiple abortions but was negative. Venereal disease research laboratory test also was negative.
On admission, the patient was drowsy. Blood pressure was 220/130 mmHg. Pedal edema was present. CVS - mild tachycardia. RS was normal. No focal neurological deficit was present. Fundoscopy showed papilledema with hypertensive retinopathy changes. Investigations revealed hemoglobin-14.1 g%, total leucocyte count-16480, N74 L 22, platelets - 4.7 Lk/cc, postprandial blood sugar - normal, random blood sugar: 140 mg/dl, B urea: 56 mg%, serum Creatine: 1.6 mg%, serum electrolytes were normal. Urine ketone bodies - negative, Alb: 3+, Sugar: Nil, pus cells: 10-15, thyroid profile - N, urine C/S showed no growth. 24 h urine protein 2.67 g/4700 ml, CT head was normal. Renal artery Doppler showed Grade 1 MRD, No renal artery stenosis, features suggestive of left extra-adrenal paraganglioma present. 24 h urine metanephrines: 462 mcg/day (N: <350/mcg/day). Plasma NA: 1868 pg/ml (N < 600), plasma adrenaline: 247 pg/ml (N < 125), serum PTH: 53.3 pg/ml (N: 65 pg/ml). Magnetic resonance imaging (MRI) abdomen showed evidence of a well-defined heterogeneous soft tissue mass of 3.6 cm × 3.8 cm × 6.2 cm in the left paraaortic region, distal to the level of the left renal artery with a possibility of extra-adrenal paraganglioma [Figure 1].
|Figure 1: Magnetic resonance imaging abdomen showing a well-defined heterogeneous soft tissue mass of 3.6 cm × 3.8 cm × 6.2 cm in the left paraaortic region (arrow) distal to the level of the left renal artery with a possibility of extra-adrenal paraganglioma|
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I-131 metaiodobenzylguanidine (MIBG) whole body scan findings were consistent with solitary MIBG avid neuroendocrine tumor (pheochromocytoma/paraganglioma) in the left paramedian region corresponding to the mass lesion described in MRI report. A final diagnosis of paraganglioma with type 2 DM, secondary HTN was made. The patient underwent laparoscopic resection of the mass without any complication. Biopsy report showed well-circumscribed tumor composed of nests of large polyhedral cells having abundant granular cytoplasm enlarged vascular nuclei. Maximum mitotic figures 2/10 hpf. No evidence of necrosis or capsular invasion. All features were compatible with extra-adrenal paraganglioma. The patient was stable in postoperative period. The patient was normotensive and euglycemic without antihypertensive and antidiabetic medications in the 6 months postoperative follow-up period.
| Discussion|| |
Paragangliomas are rare neuroendocrine tumors that arise from the extra-adrenal autonomic paraganglia consisting mainly of neuroendocrine cells that are derived from the embryonic neural crest and have the ability to secrete catecholamines. Some physicians call paraganglioma a "pharmacological time bomb" because of its danger. Paragangliomas are closely related to phaechromocytomas (which are sometimes referred to as intra-adrenal paragangliomas) and are indistinguishable at the cellular level. Sympathetic paragangliomas usually secrete catecholamines and are located in the sympathetic paravertebral ganglia of thorax, abdomen, and pelvis. In contrast, most parasympathetic paragangliomas are nonfunctional and located along the glossopharyngeal and vagal nerves in the neck and at the base of the skull.
Catecholamine-secreting paragangliomas often present clinically such as pheochromocytomas with HTN, episodic headache, sweating, and tachycardia. About 97% are benign and cured by surgical removal; the remaining 3% are malignant. About 85% of paragangliomas develop in the abdomen, 12% in the chest and 3% in the head and neck region. While most are single rare multiple cases occur (usually in a hereditary syndrome) . In patients who are thought to have a paraganglioma, biochemical tests should be done to measure the levels of catecholamines and metanephrines. The reason that many physicians rely on the metanephrines levels more than the catecholamine levels is that adrenaline only lasts a short time in the body before it is broken down, while metanephrines last much longer in the body. Catecholamine and metanephrines levels may be measured in either the plasma (i.e., blood) or in a 24 h urine collection. Although the National Institute of Health recommends plasma metanephrines for patients with an incidentally discovered adrenal tumor, many physicians feel that the 24 h urine test is better than the plasma test because it has fewer false positives. Levels that are at least twice the upper limit of normal levels confirm that the patient has a paraganglioma. Certain medications and certain conditions can lead to false positive results: Tricyclic antidepressants (including cyclobenzaprine hydrochloride), levodopa, ethanol (alcohol) withdrawal, withdrawal from clonidine and other drugs (e.g., illicit drugs), antipsychotics, buspirone hydrochloride, and bupropion hydrochloride, amphetamines, prochlorperazine, reserpine, major physical stress (e.g., surgery, stroke), obstructive sleep apnea syndrome. When the diagnosis is confirmed with plasma or urine studies, the patient should have a CAT scan or MRI to identify the location of the paraganglioma. Nuclear medicine tests like an MIBG scan or PET scan (i.e., positron emission tomography scan) can be helpful. These tests use a weakly radioactive particle to home into the tumor so that it "lights up" on X-ray. The MIBG scan is specific for adrenaline-producing tumors while the PET scan identifies any very metabolically active tumors. Suspicious masses should never be biopsied unless a paraganglioma has been ruled out with biochemical tests. Even then, a biopsy is rarely helpful or necessary. The best treatment for paraganglioma is to surgically remove the tumor. Medication (alpha-blockers) is to be given in increasing doses over 10-14 days before surgery to block the effects of excess adrenaline production. Shortly before surgery (1-3 days before), ß-blockers may be administered to slow the fast heart rate. Most of the metabolic abnormalities, including hyperglycemia, are corrected following the surgical removal of the tumor. Having a paraganglioma while being pregnant is rare. Once a diagnosis is made, MRI is the imaging test of choice because it avoids radiation to the developing baby. When deciding on how to treat a pregnant woman with paraganglioma, in general doing what is best for the mother is best for the baby. At <24 weeks of pregnancy, surgery (laparoscopic or open) is performed after alpha blockade. After 24 weeks, pharmacologic blockade is started. Most physicians advise delivering the baby through C-section and either removing the paraganglioma at the same time or 4-6 weeks later. Obstetricians who specialize in high-risk pregnancies are a critical part of the management team. To conclude, paragangliomas are rare neuroendocrine tumors that should be considered in the differential diagnosis in a patient presenting with an episodic headache and HTN. New-onset hyperglycemia or worsening of preexisting diabetes may be the presenting feature in some patients with paragangliomas.
JSS Hospital, Mysore, Karnataka, India.
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Conflicts of interest
There are no conflicts of interest.
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