Localization of pheochromocytoma by selective venous catheterization and assay of plasma catecholamines.

The diagnosis of pheochromocytoma rests primarily on determination of the 24-hour urinary excretion of catecholamines and their metabolites. In most cases nephrotomography and selective arteriography or venography, or both, are sufficient to localize the tumour. Selective venous catheterization and the assay of plasma catecholamines should be considered for pheochromocytoma localization in: (a) patients in whom standard techniques fail to localize the tumour; (b) patients who exhibit idiosyncratic reactions to the angiographic contrast materials; (c) young patients or patients with familial pheochromocytoma, including those with multiple neurofibromatosis or multiple endocrine adenomatosis, type 2; (d) patients with recurrent, malignant, or suspected multicentric or extra-adrenal tumours; and (e) patients excreting only norepinephrine in the urine. The validity of the results is particularly dependent on the skill with which venous catheterization is carried out.     

Evaluation of the usefulness of certain localization methods in diagnosis of pheochromocytoma]

Localization tests including TC-scans, scintigraphy with 131I-radiolabelled metaiodobenzylguanidine and ultrasound have been performed in 68 patients with diagnosed pheochromocytoma. Diagnosis was based on clinical symptoms and increased catecholamines and/or their metabolites excretion with the urine. Proper diagnosis with CT-scans was 97%, scintigraphy--92%, and ultrasound--93%; false negative results in scintigraphy amounted to 8% (3 patients) and 5% (3 patients) in case of ultrasound. CT-scans were free of such errors. False positive diagnosis was made in 2 (3%) patients with CT-scans and in 1 (2%) patient tested with ultrasound. These results suggest that pheochromocytoma may be precisely localized with non-invasive techniques, especially CT-scans.     

Diminished circadian blood pressure rhythm in patients with asymptomatic normotensive pheochromocytoma

In our study, the circadian blood pressure (BP) rhythm was studied in subjects with asymptomatic and normotensive pheochromocytoma. We have therefore performed 24-hour BP monitoring not only in 6 subjects with asymptomatic pheochromocytoma, but also in 33 patients with symptomatic pheochromocytoma and in 10 normotensive subjects, who served as a control group. Circadian BP rhythm was expressed by assessing a relative night-time BP decline. We found a similar BP rhythm, catecholamine excretion and tumor size in subjects with both forms of pheochromocytoma. Subjects with asymptomatic pheochromocytoma had a significantly lower night-time systolic BP decline (P=0.01) and diastolic BP decline (P=0.006) than normotensive controls. We conclude that the attenuated night-time BP decline in normotensive and asymptomatic subjects with pheochromocytoma might be a possible sign of partial desensitization of the cardiovascular system to catecholamines.     

Control of catecholamine release and blood pressure with octreotide in a patient with pheochromocytoma: a case report with in vitro studies

A 65-year-old male patient with pheochromocytoma, whose hypertensive episodes were uncontrolled using conventional therapy, was successfully treated with octreotide (SMS 201-995). The serum catecholamine level and the urinary excretion of catecholamines decreased after 300 microgram/day of octreotide was administered. To clarify the mechanisms of octreotide that lower catecholamine released from a tumor, we studied the in vitro effects of octreotide on membrane potentials and voltage-dependent Ca(2+) channel (VDCC) current using the whole-cell patch-clamp technique in single pheochromocytoma cells dispersed after tumor resection. The action potentials were reversibly inhibited with 10 microM octreotide. In addition, the VDCC current evoked by depolarized pulses from the holding potential of -60 mV was inhibited with 10 microM octreotide. Octreotide is useful for controlling blood pressure before surgery in some patients with uncontrolled hypertension caused by a pheochromocytoma.     

Serum chromogranin-alpha immunoradiometric assay in the diagnosis of pheochromocytoma

BACKGROUND: The diagnosis of pheochromocytoma is based on laboratory tests that demonstrate an increase in urinary excretion of catecholamines or their metabolites. Chromogranin A (CgA) is a member of the granin family and is widely distributed in neuroendocrine cells and particularly in chromaffin adrenal cells. Consequently, serum CgA increases in patients affected by pheochromocytoma and other diseases of the chromaffin system. AIM: This study investigated the performance of serum CgA assay in the diagnosis of pheochromocytoma and compared serum CgA with 24-hour urinary epinephrine (E), norepinephrine (NE), vanillylmandelic acid (VMA) and metanephrines (MNs). METHODS: We enrolled 15 patients with histologically proven pheochromocytoma; 100 healthy blood donors and 148 patients with essential hypertension were enrolled as controls. Serum CgA was assayed by a specific immunoradiometric method (IRMA). Urinary tests were done with high performance liquid chromatography (HPLC). RESULTS: Circulating CgA showed a higher sensitivity (1.00), specificity (0.96) and accuracy (0.96) than all other tests. Serum levels of CgA clearly increased from blood donors and patients with essential hypertension to patients with pheochromocytoma (p<0.0001). Furthermore, a strong relationship between serum CgA and tumor mass was found (p<0.0001). In conclusion, our data suggest that the CgA assay might be used as a single test for the diagnosis of pheochromocytoma.     

Is the platelet phenolsulfotransferase involved in the sulfoconjugation of plasma catecholamines?

Catecholamines are predominantly present in the sulfoconjugated forms in human plasma. Phenolsulfotransferase (EC 2.8.2.1), which catalyses the sulfation of phenolic compounds, is widely distributed in human tissues. In blood, a phenolsulfotransferase, more specific for catecholamine sulfation is found exclusively in platelets. Free and sulfoconjugated catecholamines were measured in plasma and platelets of healthy volunteers and compared with those present in patients with uremia or pheochromocytoma to determine the ability of platelet phenolsulfotransferase to sulfurylate plasma catecholamines. In patients with pheochromocytoma, the rise in free and sulfoconjugated plasma catecholamines is accompanied by a simultaneous rise of these molecules in platelets. In uremia, where the level of plasma catecholamines is normal, the rise in the sulfoconjugates is not accompanied by a concomitant increase in either free or sulfoconjugated catecholamines in platelets. Platelet phenolsulfotransferase activity remains unchanged in pheochromocytoma and uremia. These data indicate that the platelet phenolsulfotransferase is involved in the sulfation of the catecholamines present in platelets, but its contribution, if any, to the high level of sulfoconjugated catecholamines found in plasma is negligible. This assertion is confirmed by our observations in thrombocytopenic patients. Indeed, despite the very low number of platelets and the absence of plasma phenolsulfotransferase activity, thrombocytopenic patients have normal plasma levels of free and sulfoconjugated catecholamines.     

The renin-angiotensin-aldosterone system in Cushing's syndrome and pheochromocytoma

We investigated the status of the renin-angiotensin-aldosterone axis in 5 patients with Cushing's syndrome and 7 patients with pheochromocytoma. In most of the patients with Cushing's syndrome no significant abnormalities of the renin-angiotensin-aldosterone system could be detected. In 4 out of 7 patients with pheochromocytoma, plasma renin activity remained high after saline suppression and decreased into the normal range in all 4 patients after removal of pheochromocytoma. These results imply that the postulated mineralocorticoid excess was not present in the patients with Cushing's syndrome studied. In pheochromocytoma, high levels of plasma catecholamines contribute to a high renin state which may have pathophysiologic implications.     

Urinary Pyrophosphate in Normal Subjects and in Stone Formers

The urinary excretion of inorganic pyrophosphate was determined in nine normal subjects and also in eight patients with recurrent calcium-containing renal stones during varied levels of phosphate intake. The excretion of pyrophosphate and orthophosphate is virtually the same in the two groups at all levels of phosphate intake. It appears unlikely that a consistently reduced urinary excretion of pyrophosphate is a factor in the formation of urinary calculi. Pyrophosphate excretion rose and calcium excretion fell with increasing phosphate intake; this might be expected to have a beneficial effect in patients with recurrent calcium stones.     

In vivo evidence of regulation by pituitary-adrenal axis of urinary epinephrine excretion in men

The effect of the pituitary-adrenal axis on epinephrine synthesis in the human adrenal medulla was examined by the estimation of the 24-h urinary epinephrine level after treatment with glucocorticoids in four patients with systemic lupus erythematodes (SLE), one patient with rheumatoid arthritis (RA) and one patient with adrenal pheochromocytoma. 24-h urinary catecholamines (CAs) were measured by HPLC before and after glucocorticoid treatment, dexamethasone or prednisolone was orally given for more than seven days to patients with SLE, RA or isolated ACTH deficiency and five days to a patient with adrenal pheochromocytoma. In patients with isolated ACTH deficiency, the 24-h urinary epinephrine level was significantly lower than the normal range. In patients with SLE or RA, the 24-h urinary epinephrine level was normal and it was significantly suppressed by therapeutic doses of prednisolone 30-40 mg/day. In a patient with adrenal pheochromocytoma, 24-h urinary epinephrine was extremely high and it was significantly increased after dexamethasone 0.5 mg/day. These results suggest that epinephrine synthesis in the human adrenal medulla may be dependent on the pituitary-adrenal axis. But the increase in epinephrine synthesis due to dexamethasone in a patient with pheochromocytoma may reflect the direct effect via the feeding artery to the tumor, as previously shown in an in vitro culture system.     

Differential secretion of opioid peptides and catecholamines from cultured cells of a human pheochromocytoma tumor

Dissociated cells from a human pheochromocytoma tumor were maintained in culture, and the secretion of opioid peptides (OP), endogenous catecholamines (CA) and preloaded [³H] norepinephrine from these cells was examined. Nicotine, veratridine, barium or Ionomycin stimulated the secretion of OP, endogenous CA and ³H from the pheochromocytoma cells. In general, the different secretagogues were more potent in releasing OP than endogenous CA; ³H secretion was intermediate. Secretion of OP was more sensitive to stimulation by the calcium ionophore Ionomycin and by veratridine than was CA secretion. Nicotine-evoked OP secretion was more sensitive to extracellular calcium concentration than was secretion of CA or ³H. In contrast, bovine adrenal chromaffin cells show no such differential secretion of OP and CA in response to Ionomycin stimulation or to nicotine stimulation under conditions of varying extracellular calcium concentration. The results show that human pheochromocytomas secrete OP as well as CA and that there may be heterogeneous storage pools of CA and OP in cultured pheochromocytoma cells.     

Effect of parathyroid extract on renal cyclic AMP excretion in patients with normocalciuric nephrolithiasis.

It is uncertain whether normocalcemic, normocalciuric patients with calcium nephrolithiasis have a disorder of calcium metabolism. We studied the effect of a parathyroid extract (PTE) INFUSION (1.4 U/kg body weight) on the urinary cyclic AMP excretion in 16 such patients. For comparison, we investigated groups of normal individuals and patients with primary hyperparathyroidism, renal insufficiency and different gastrointestinal diseases. The increase of cyclic AMP above basal excretion in patients with nephrolithiasis was only 1.2 +/- 0.3 mumol/h (mean +/- SEM), versus 2.5 +/- 0.5 mumol/h in normal subjects (p less than 0.05) although the basal excretion was similar. Patients with renal insufficiency had low basal excretion of cyclic AMP and little stimulation of excretion by PTH (increase, 0.3 +/- 0.06 mumol). Patients with primary hyperparathyroidism had high baseline cyclic AMP excretion but sub-normal stimulation by PTE (increase, 0.46 +/- 0.13); in contrast, patients with different gastrointestinal disease had high baseline excretion and supranormal stimulation of cyclic AMP excretion (increase, 5.2 +/- 0.6). We speculate that an impaired response to PTH might be involved in the slightly increased urinary calcium excretion in normocalcemic stone formers suggested by others.     

Determination of three major catecholamines in human urine by capillary zone electrophoresis with chemiluminescence detection

A sensitive simple method is presented for the determination of three major catecholamines in human urine by capillary electrophoresis (CE) with on-line chemiluminescence (CL) detection. This was also the first time that the luminol-Ag(III) complex CL system was used for CE detection. This method was based on the enhancing effect of epinephrine (EP), norepinephrine (NE), and dopamine (DA) on the CL reaction between luminol and the Ag(III) complex in alkaline solution. The separations and determinations were performed with an electrophoretic buffer consisting of 20.0mM sodium borate and 1.0mM luminol. Under optimized conditions, the three catecholamines were baseline separated and detected in less than 8 min. Detection limits of 7.9 × 10(-8)M, 1.0 × 10(-7)M, and 6.9 × 10(-8)M were observed for EP, NE, and DA, respectively. Relative standard deviation (RSD) values for the peak height were 4.7% to 5.4% (n = 5). Our proposed method was applied to the determinations of the catecholamines in urine samples from 12 healthy individuals and 26 pheochromocytoma patients. Our results suggest that this method might be useful to monitor the catecholamine levels in routine screening and to diagnose pheochromocytoma.     

131I]metaiodobenzylguanidine therapy of malignant pheochromocytoma: interference of medication

Malignant pheochromocytoma may present as a widespread metastatic disease, which is little or non-responsive to external beam radiotherapy and chemotherapy. The prognosis of these patients is bad due to both the progressive metastasis and the secretion of excess catecholamines which may cause hypertensive episodes. For these conditions [131I]metaiodobenzylguanidine (131I-MIBG) therapy may be an alternative treatment modality to induce both tumor remission and reduction of hormonal activity of the disease. The experience with 131I-MIBG therapy in four patients with metastatic malignant pheochromocytoma at The Netherlands Cancer Institute is reviewed. One patient with abdominal tumor recurrence and metastases to the lymph nodes and lungs had a partial remission of disease for 3 years; a second had a mixed response together with palliation and two other patients had stable disease, but were relieved of bone pain and severe hypertension, respectively. It is essential to be aware of the medication the patient is using, as many drugs are known or may be expected to interfere with the uptake and/or retention of 131I-MIBG by the tumor cells. The case of a significant reduction of 131I-MIBG uptake and retention by Labetalol in one of the patients is discussed. It is concluded that 131I-MIBG therapy may induce objective remission in patients with malignant pheochromocytoma and is certainly meaningful in the reduction of hormonal activity, the control of hypertension and the relief of pain from metastases.     

Effects of a prostacyclin analog iloprost on kidney function, renin-angiotensin and kallikrein-kinin systems, prostanoids and catecholamines in man

Iloprost (ZK 36 374), a stable analog of carbaprostacyclin, was infused for 72 h to nine patients with advanced obliterative arterial disease. Iloprost caused a marked vasodilation and a compensatory increase in cardiac output. The glomerular filtration rate increased by 45% and tubular reabsorption of sodium and water were reduced by 80% and 107%, respectively. The urine excretion rate increased by 122%. Tubular handling of potassium and calcium were not influenced by iloprost but magnesium reabsorption was stimulated. The renin-angiotensin system was not activated while serum angiotensin converting enzyme activity was decreased. Kallikrein excretion in urine was increased 4.4-fold but plasma kininogen, a substrate for kallikrein in producing vasoactive kinins, was unaffected by the drug. Plasma levels of 6-keto-PGF1 alpha and TxB2 were decreased and their excretion in urine increased. Plasma catecholamines were not changed by iloprost. Several of the changes persisted for at least the first postinfusion day. The results indicate that iloprost increases urine excretion rate by increasing glomerular blood flow and by inhibiting sodium and water reabsorptions. The kinin-forming system, but not the renin-angiotensin system or plasma catecholamines, may be activated. The decrease in plasma level of prostanoids can be, at least partly, due to their increased excretions in urine.     

Evaluation of risk index according to Tiselius in patients with calcium urinary stones

Daily calcium, oxalates, magnesium, citrates and creatinine excretion with the urine was determined in 36 patients with calcium renal stones and in 25 healthy individuals. Then, risk index according to Tiselius was calculated. It was found that daily calcium excretion is significantly higher and daily citrates excretion is significantly lower in patients with calcium renal stones. Daily excretion of oxalates, magnesium and creatinine with the urine did not differ in both groups. Risk index according to Tiselius was two-fold higher in patients suffering from urolithiasis than in healthy individuals (p greater than 0.001) and better illustrated the tendency to stone formation than the analysis of metabolic disorders.     

Plasma adrenomedullin concentrations in patients with adrenal pheochromocytoma.

BACKGROUND: The hypotensive peptide adrenomedullin was first isolated in extracts of human pheochromocytoma. There is, however, no information available on the behaviour of circulating adrenomedullin or on the correlation with catecholamines in patients with pheochromocytoma. OBJECTIVES: 1) to investigate whether plasma adrenomedullin levels were changed in 10 patients with pheochromocytoma when compared to 21 healthy subjects and 16 patients with essential hypertension; 2) to determine whether or not adrenomedullin has a counter-regulatory role in catecholamine excess in pheochromocytoma or is responsible for hemodynamic modifications before and after tumour resection; 3) to determine tissue distribution of iradrenomedullin in the pheochromocytoma. METHODS: Plasma adrenomedullin and catecholamine levels were measured in all patients with pheochromocytoma before and four weeks after tumour removal. In the four patients undergoing resection of tumours, plasma levels of adrenomedullin were measured at different time-points during surgery. RESULTS: The mean plasma adrenomedullin concentrations ( SD) in patients with pheochromocytoma (37.9 +/- 6pg/ml) were significantly higher (p<0.0001) than those in normal subjects (13.7 +/- 6.1 pg/mI) and patients with essential hypertension (22.5 +/- 9.lpg/ml). Adrenomedullin levels correlated with plasma noradrenaline (r = 0.516, p = 0.0124). In all patients with pheochromocytoma, plasma adrenomedullin concentrations decreased after removal of tumours (from 37.9 +/- 6 to 10.9 +/- 4.6 pg/ml; p < 0.0001). In the four patients studied during surgery, baseline plasma adrenomedullin and noradrenaline levels were markedly elevated, and increased significantly with tumour manipulation, decreasing 24 hours after operation. Adrenal medulla cells surrounding the pheochromocytoma site stained for ir-adrenomedullin, whereas only isolated cells of pheochromocytoma stained for the peptide. CONCLUSIONS: This study demonstrates that circulating adrenomedullin is increased in pheochromocytoma, and is also correlated with plasma noradrenaline levels. Adrenomedullin may represent an additional biochemical parameter for clinical monitoring of patients with pheochromocytoma.     

Comparison of calcium oxalate values as indicators of risk for calcium oxalate calcinosis and the degree of urine saturation in patients with calcium urolithiasis and in healthy patients

Daily excretion of calcium, magnesium, oxalates, and citrates together with daily urine output were determined in 37 patients with calcium urolithiasis and in 25 healthy individuals. Basing on the obtained values, a degree of urine saturation with calcium oxalate with Marshall and Robertson technique and a value of risk factor with Tiselius technique were calculated. It was found that daily diuresis and excretion of calcium with the urine are significantly higher in patients with urolithiasis where as daily excretion of citrates with the urine is significantly lower than in healthy individuals. Risk index proved two-fold higher in the examined patients than in the healthy individuals (p greater than 0.001) while the degree of urine saturation with calcium oxalate did not differ significantly in both groups. The authors, discussing causes of seemingly different changes in both tested parameters, stressed diagnostic value of risk index which includes excretion of crystallization inhibitors (magnesium, citrates) and contrary to the degree of urine saturation is independent of daily urine output.     

Use of plasma catecholamines in diagnosing pheochromocytoma and neuroblastoma

The diagnosis in two cases of neural crest tumours was confirmed by the measurement of concentration of plasma catecholamines. A histamine provocative test monitored by values of plasma catecholamines provided support for a diagnosis of pheochromocytoma in a patient with normal blood pressure and elevated values of urinary amines. In the second case the presence of a ganglioneuroblastoma secreting abnormal amounts of catecholamines was detected by plasma epinephrine and norepinephrine measurements when values of urinary free catecholamines were normal.     

Pheochromocytoma: A Cause of St-Segment Elevation Myocardial Infarction,Transient Left Ventricular Dysfunction,and Takotsubo Cardiomyopathy

ObjectiveTo report the case of a patient with a pheochromocytoma and apical left ventricular dysfunction that resolved after surgical resection of the pheochromocytoma, to review the effects of catecholamines on myocyte function and the concept that takotsubo cardiomyopathy (TC) is caused by excess catecholamines, and to illustrate the difficulty in the management of an acute coronary syndrome (ACS) during a hypertensive crisis attributable to a pheochromocytoma.MethodsWe present the clinical history, physical findings, laboratory results, and imaging studies in a 60-year-old man with an ACS, TC, and an incidentaloma later diagnosed to be a pheochromocytoma. The association with TC and the pertinent literature are reviewed.ResultsA 60-year-old man was suspected of having myocardial ischemia on the basis of symptoms of paroxysmal chest pain extending to the left shoulder, diaphoresis, ST-segment elevation on an electrocardiogram, and elevated serial levels of cardiac enzymes. Coronary angiography did not reveal substantial coronary artery obstruction but detected ballooning of the apical, anterior, and inferior cardiac walls, consistent with TC. He had a history of labile hypertension and palpitations of 3 months’ duration. An adrenal mass detected on a prior computed tomographic scan and increased 24-hour urine catecholamine levels were consistent with a pheochromocytoma. Treatment with phenoxybenzamine was initiated, and he underwent a right adrenalectomy, which confirmed that the tumor was a pheochromocytoma and dramatically improved the patient’s condition.ConclusionPheochromocytomas manifest with labile blood pressures and should be considered in the differential diagnosis of ACS. This case also supports the concept that TC is caused by excess catecholamines. (Endocr Pract. 2012;18:e77-e80)