History
It has been shown that a relatively large number of these tumors remain undiagnosed during life, suggesting that some of those tumors present with nonspecific signs and symptoms. In addition, the low medical alertness in evaluating the signs and symptoms could represent a silent clinical presentation—the subclinical pheochromocytoma. It is also known that the clinical picture depends on the capacity of the tumors to release catecholamines and/or other peptides. Subclinical pheochromocytomas are often discovered as incidentalomas during radiological procedures or during routine screening for pheochromocytoma in carriers of mutations in 1 of the 10 currently identified tumor-susceptibility genes. [13]
Pheochromocytomas typically produce paroxysmal episodes that may include any of the following:
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Hypertension (80%)
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Diaphoresis (71%)
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Palpitation with or without tachycardia (64%)
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Pallor (40%)
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Nausea with or without vomiting (42%)
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Tremor (31%)
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Weakness or exhaustion (28%)
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Nervousness or anxiety (22%)
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Epigastric pain (22%)
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Chest pain (19%)
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Dyspnea (19%)
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Flushing or warmth (18%)
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Numbness or paresthesia (11%)
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Blurred vision (11%)
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Tightness of throat
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Dizziness
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Convulsion
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Pain in the neck, shoulder, extremities, or flank
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Tinnitus
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Dysarthria
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Unsteadiness
These paroxysms occur at varying intervals, from several times a day to once every month or more; however, in children, hypertension is most often sustained. All patients with pheochromocytoma experience hypertension at some point.
Hypertension appears to be uniformly present and is sustained in 80-90% of affected children at the time of diagnosis. Occasionally, children with sustained hypertension also have paroxysmal episodes. The paroxysms are occasionally precipitated by excitement or a particular physical activity, such as bending over or lifting a heavy object. Convulsions secondary to hypertensive encephalopathy may occur.
Wide fluctuations in blood pressure are characteristic, and marked increases may be followed by hypotension and syncope. When the blood pressure is elevated, postural hypotension may also be present.
Other associated cardiovascular complications seen mainly in adults include serious ventricular arrhythmias or conduction disturbances, reversible dilated or hypertrophic cardiomyopathy, and Takotsubo cardiomyopathy (also known as stress-induced cardiomyopathy). [14]
Headache is the most frequent symptom in children (75%), followed by sweating in two thirds of patients and nausea and vomiting in half of patients. These headaches are usually described as pounding.
Pallor is usually present because of the intense alpha-receptor–mediated peripheral vasoconstriction, which causes cool, moist hands and feet, and facial pallor.
Palpitations, mediated by beta1 receptors, reflect increased cardiac output and heart rate.
Hyperthermia or flushing secondary to decreased heat loss and increased metabolism leads to reflex sweating.
Poor weight gain or severe cachexia may develop because of hypermetabolism. The child may have a good appetite but, because of hypermetabolism, does not gain weight.
Polyuria and polydipsia may result from increased glycolysis and alpha-receptor–mediated inhibition of insulin release. This insulin inhibition causes an increase in blood sugar levels and glucose intolerance. As a result, patients may present with diabetes mellitus or glucose intolerance, most commonly during paroxysms.
Hypercalcemia is an uncommon but well-recognized complication that may reflect associated hyperparathyroidism, particularly in familial cases.
A syndrome consisting of watery diarrhea, hypokalemia, and achlorhydria secondary to the ectopic production of vasoactive intestinal peptide has been described. This syndrome, along with other laboratory markers of dehydration, such as elevation of the blood urea (BUN) level and hematocrit, usually resolves when the tumor is removed.
The clinical course of pheochromocytoma may be adversely affected by drugs or diagnostic studies that affect catecholamine metabolism, such as opiates, cold medicine, decongestants, and some contrast dyes.
In severe cases, precordial pain may radiate into the arms. Pulmonary edema and cardiac and hepatic enlargement may also develop.
Affected children are often emotionally labile and have an anxious expression. Occasionally, these children are labeled hyperactive with an attention deficit disorder.
Nocturnal enuresis that does not respond to fluid restriction and voiding before bedtime may develop.
Physical Examination
Patients with pheochromocytomas usually have a thin body habitus. The presence of obesity does not rule out pheochromocytomas, however.
Hypertension may be present in both arms and legs. During a paroxysm, the blood pressure may range from 180-260 mm Hg systolic and from 120-210 mm Hg diastolic. Upon cardiovascular examination, tachycardia with forceful heartbeat is often found and is easily palpable. Postural hypotension may be present
Patients may feel warm and have pallor of the face and chest. Body perspiration and cool, moist hands and feet may also be found.
A mass may be palpable in the neck or in deep palpation of the abdomen. Deep palpation of the abdomen may produce a typical paroxysm.
Hypertensive retinopathy and cardiomyopathy are often present. Ophthalmoscopic examination may reveal papilledema, hemorrhages, exudates, and arterial constriction.
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Axial, T2-weighted MRI scan showing large left suprarenal mass of high signal intensity on a T2-weighted image. The mass is a pheochromocytoma.
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Abdominal CT scan demonstrating left suprarenal mass of soft tissue attenuation representing a paraganglioma.
