|Year : 2014 | Volume
| Issue : 2 | Page : 136-139
Unusual presentation of pheochromocytoma
Rajendra B. Nerli1, Ranjeeth A. Patil1, Pravin Patne1, S. N. Suresh1, Murigendra B. Hiremath2
1 Department of Urology, KLES Kidney Foundation, KLE University's JN Medical College, KLES Dr. Prabhakar Kore Hospital and MRC, Belgaum, Karnataka, India
2 PG Department of Biotechnology and Microbiology, Karnatak University, Dharwad, Karnataka, India
|Date of Web Publication||20-May-2014|
Rajendra B. Nerli
Department of Urology, KLES Kidney Foundation, KLE University's JN Medical College, KLES Dr. Prabhakar Kore Hospital and MRC, Belgaum - 590 010, Karnataka
Source of Support: None, Conflict of Interest: None
Pheochromocytomas are rare catecholamine-secreting tumors that arise from chromaffin tissue within the adrenal medulla and extra-adrenal sites. Due to the excess secretion of hormones, these tumors often cause debilitating symptoms and a poor quality-of-life. Although medical management plays a significant role in the treatment of pheochromocytoma patients, surgical excision remains the only cure. Pheochromocytoma usually has three classic symptoms-headache, sweating and heart palpitations (a fast heart beat) in association with markedly elevated blood pressure (hypertension). Hormones such as catecholamines and metanephrines are measured in a 24 h urine collection and metanephrines may also be measured in the blood, to make a diagnosis of pheochromocytoma. If these are greater than 2 times the normal level, imaging studies are usually done to look at the adrenal glands. We report on three cases of pheochromocytoma, which had unusual presentation.
Keywords: Biochemical diagnosis, catecholamines, computed tomography, localization, magnetic resonance imaging, metanephrines, metaiodobenzylguanidine, pheochromocytoma
|How to cite this article:|
Nerli RB, Patil RA, Patne P, Suresh SN, Hiremath MB. Unusual presentation of pheochromocytoma. J Sci Soc 2014;41:136-9
| Introduction|| |
Pheochromocytoma is a tumor of the catecholamine-producing cells of the adrenal medulla. Approximately, 1-2/100,000 individuals is diagnosed annually with pheochromocytoma, although reports on incidence vary.  Pheochromocytoma is a very rare tumor and is responsible for only 0.5% of cases of hypertension.  They form 5% of all incidentally detected adrenal masses  and 10-25% of all pheochromocytomas are incidentally discovered lesions. , Cells of the adrenal medulla possess the enzyme phenylethanolamine-N-methyl transferase (PNMT), which gives them the ability to synthesize epinephrine from norepinephrine.  Pheochromocytomas are known to vary in their enzymatic composition and in their ability to self-metabolize the catecholamines within each tumor's secretory vesicles. Therefore, this could lead to great variability in the amount and ratio of catecholamines secreted by pheochromocytomas.  Indeed these differences in norepinephrine, epinephrine and dopamine secretion explain the heterogeneity in clinical behavior of pheochromocytomas. It is well-known that patients with the rare tumors that secrete primarily epinephrine (usually limited to those that arise from the adrenals or from the organ of Zuckerkandl), tend to experience syncopal or hypotensive episodes due to epinephrine's vasodilatory action through the β2 receptor, while those patients with predominantly norepinephrine-secreting tumors (e.g., patients with von Hippel-Lindau [VHL] syndrome) present with hypertension and sweating, given the compound's affinity for the vasoconstricting α-adrenoreceptor.  We report on three cases of pheochromocytoma with unusual presentation.
| Case reports|| |
We present a case of a 48-year-old male patient presented with the left flank pain. The pain was episodic, dull aching of mild to moderate intensity. Patient was otherwise fine. Physical examination revealed no positive findings. The patient was non-hypertensive. Abdominal sonography revealed a 6 cm × 5 cm hypoechoic left adrenal mass. The computed tomography (CT) [Figure 1]a and b confirmed the adrenal mass (5.8 cm × 5.1 cm × 4.9 cm). Serum catecholamine levels (Serum adrenaline 75 pg/ml and Serum noradrenaline 600 pg/ml) were within the normal range and so was the 24 h urinary vanillylmandelic acid (VMA) (7.8 mg/24 h). Patient was started on α and β blockers pre-operatively. There was a varied variation in blood pressure following induction of anesthesia. The blood pressure was controlled and maintained by use of intravenous vasodilators, dopamine and cortico-steroids. The patient underwent lt. adrenalectomy and histologically reported as Pheochromocytoma. Sections showed neoplasm composed of polygonal cells. The neoplasm was rich in vascularity. The cytoplasm appeared granular and the nuclei showed a salt and pepper pattern.
|Figure 1: Computed tomography image showing the adrenal mass (5.8 cm × 5.1 cm × 4.9 cm)|
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This paper report a case of a 54-year-old male patient presented with a history of dyspepsia. The patient was a known hypertensive and on medications for the past 3 years. He was a recently diagnosed diabetic on oral hypoglycemic agents. Patient was a known case of gastritis and on medications. Abdominal sonography revealed a 7 cm right adrenal mass. CT revealed a well-defined peripherally enhancing mass (7.8 cm × 7.6 cm × 7.4 cm) [Figure 2]a and b. The 24 h urinary VMA was 8.8 mg/day and serum catecholamine values (Serum adrenaline 80 pg/ml and Serum noradrenaline 625 pg/ml) were within normal range. The patient was prepared for surgery with pre-operative tablet prazocin 5 mg/day. Patient underwent Rt. Adrenalectomy under general anesthesia. During induction of anesthesia, the patient's blood pressure showed several peaks and un-stability. The patient had a smooth post-operative period and the histology of the tumor was reported as pheochromocytoma.
|Figure 2: Computed tomography image showing a welldefined peripherally enhancing mass (7.8 cm × 7.6 cm × 7.4 cm)|
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A 37-year-old male patient presented with an incidentally diagnosed Rt. adrenal mass on CT. The imaging was indicated for acute abdominal pain on the contralateral side secondary to ureteric stone. The patient was non-hypertensive and non-diabetic. The mass was well-defined and 4.8 cm × 4.4 cm × 4.2 cm in size. Serum catecholamines (Serum noradrenaline 550 pg/ml and serum adrenaline 85 pg/ml) and 24 urinary levels of VMA (8.2 mg/24 h) were within the normal ranges. The patient was prepared for surgery with low doses of α and β blockers pre-operatively. The patient underwent laparoscopic right adrenalectomy. The histopathological examination revealed a pheochromocytoma.
| Discussion|| |
Pheochromocytoma is a catecholamine-producing tumor arising in the adrenal medulla. Its clinical hallmark is sustained or intermittent hypertension often associated with paroxysmal symptoms.  Pheochromocytoma should also be considered if a patient has labile hypertension, hypertension resistant to antihypertensive therapy, or paroxysmal symptoms ("spells"). , Correct diagnosis is important because resection of the tumor dramatically reverses the clinical symptoms and may cure the hypertension.  A missed or delayed diagnosis may cause considerable morbidity and mortality. , Biochemical testing is the first step in the evaluation of patients suspected of pheochromocytoma. If metabolic testing is positive, appropriate imaging is undertaken to localize the source of the catecholamine excess.  Clinical evaluation depends on both radiographic imaging and more importantly, on biochemical testing.
All patients with suspected pheochromocytoma should undergo biochemical testing. In the past, measurement of both urinary and serum catecholamine levels was the mainstay for evaluation of pheochromocytoma. Due to the sensitivity (≈85%) and specificity (≈85%) of these tests, this strategy has been largely replaced by measurements of levels of metanephrines-the methylated metabolites of catecholamines.  Conversion of catecholamines to metanephrines is an uninterrupted process within pheochromocytomas, thereby measurement of plasma concentration of metanephrines is a much more sensitive means of tumor detection than the measurement of rises in plasma catecholamines, which may be paroxysmal. ,
Because (VMA) is the primary end metabolite of catecholamines, its measurement in urine has long been used for diagnosis of pheochromocytoma. Nevertheless, synthesis of VMA requires deamination of catecholamines, or their metabolites, by the monoamine oxidase enzyme, and occurs not only in the adrenal medulla, but also in the sympathetic nervous system. Moreover, the sympathetic nervous system lacks the ability to produce epinephrine, due to the absence of the PNMT enzyme and therefore only contributes to the serum level of normetanephrine (from norepinephrine), but not metanephrine (from epinephrine). Therefore the relative rise of VMA levels in the presence of a pheochromocytoma is much less dramatic than the rise seen in the levels of metanephrines and the sensitivity of urine VMA levels is therefore low (below 65% in some series).  However, the specificity of the test is high, especially in non-familial cases (99%). 
All our patients showed no clinical or biochemical evidence of pheochromocytoma. The basic biochemical tests consisting of serum catecholamines and 24 h urinary VMA were within the normal ranges. The first suspicion of pheochromocytoma was when they were induced for anesthesia. Instability of blood pressure and tachycardia were the telltale signs of cathecholamine secretion. We had started all these three patients with the pre-operative use of α and β blockers because of prior experience in dealing with such lesions.
The optimal approach to biochemical confirmation of catecholamine-secreting tumors is debatable. , There are several issues that affect the approach to diagnostic testing for pheochromocytoma. Clinicians have several options when testing for pheochromocytoma. The choice of biochemical testing for pheochromocytoma should be directed by the degree of the clinical suspicion for this serious, but rare, neoplasm. High risk scenarios include patients with pallor spells, a vascular adrenal mass, and a genetic syndrome that increases the risk for pheochromocytoma (e.g., multiple endocrine neoplasia type 2A or 2B, VHL syndrome, neurofibromatosis type 1, or familial paraganglioma), a past history of pheochromocytoma, or a family history of pheochromocytoma. In these higher probability (and less common) clinical settings, a high sensitivity test that lacks specificity (e.g., fractionated plasma free metanephrines) and downstream imaging to exclude pheochromocytoma can be justified. However, the more common clinical scenarios are those that have a low probability of pheochromocytoma and include poorly controlled hypertension, flushing spells, palpitations and adrenal incidentalomas with an adrenocortical phenotype. In these clinical settings, a high specificity test with acceptable sensitivity (e.g., 24-h urinary metanephrines and catecholamines) may be the test of choice to avoid an excessive rate of false positive tests in a low risk population. 
| Conclusions|| |
Pheochromocytoma is a tumor of chromaffin cells, which secrete catecholamines, predominantly norepinephrine, as well as epinephrine and rarely dopamine. Clinical features result from excessive catecholamine levels; the most common of these features is hypertension. The majority of pheochromocytomas are sporadic, however recent studies suggest that up to 25% of cases are hereditary. Treatment is surgical excision of the tumor, following pre-operative treatment of hypertension. Occasionally, pheochromocytomas can present with unusual forms, such as without clinical/biochemical evidence.
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[Figure 1], [Figure 2]