Excretion of adrenaline, noradrenaline, vanilmandelic acid and metanephrines in 64 patients with pheochromocytoma. Results of repeated analyses in patients with sustained and paroxysmal hypertension

Long-term results in 64 patients operated upon for pheochromocytoma

During the years 1956-1982, 64 pheochromocytoma patients were operated upon without mortality. Twenty-eight patients had sustained hypertension and 29 paroxysmal hypertension only. In two patients high blood pressure was not related to pheochromocytoma and five subjects were normotensive. In two women the pheochromocytoma demonstrated malignancy by widespread metastases. Sixteen patients also had neuroectodermal manifestations other than pheochromocytoma. Preoperatively, heart disease was found in most of the hypertensive patients aged 50 years or more at operation, but was uncommon in the others. In these subjects, heart disease persisted after surgery. Young subjects with sustained hypertension were not less affected by preoperative cerebrovascular accidents than older subjects. After surgery, hypertension persisted in 12 patients, and was easily controlled by drug therapy in eight. Nine patients died 7 months-18 years after surgery. In no case was the death directly associated with the pheochromocytoma disease. Three died from other neuroectodermal abnormalities. The 55 surviving patients have been followed up for a mean of 12 years after surgery. During the observation time the survival of the pheochromocytoma patients was similar to that of the normal population. At the end of the study, 44 out of the 55 surviving patients were free from symptoms.

The blood volume in pheochromocytoma patients before and during treatment with phenoxybenzamine

Total blood volume (TBV), red cell volume (RCV) and plasma volume (PV) were determined in 15 pheochromocytoma patients (9 males and 6 females) prior to and during preoperative treatment with phenoxybenzamine. Seventeen healthy male volunteers served as controls. Untreated male patients did not differ from the controls with respect to TBV, RCV or PV. In the total group of pheochromocytoma patients, phenoxybenzamine, in a dose of 145.6 +/- 45.2 (SD) mg/day over 14.3 +/- 5.7 (SD) days, induced significant increases in TBV (+9.4%) and PV (+14.5%), whereas RCV remained unchanged. During phenoxybenzamine, the mean PV in male patients significantly exceeded the control mean. We conclude that pheochromocytoma patients adapt their TBV to excessive catecholamine production and that they rarely present with profound hypovolemia. Moderate but higher doses of phenoxybenzamine than previously recommended induced marked increases in TBV secondary to PV expansion. Phenoxybenzamine counteracts the development of hypovolemia most effectively, thereby constituting one of several important measures for successful surgical management of pheochromocytoma patients.

Positive correlation between urinary excretion of catecholamine metabolites and tumour mass in pheochromocytoma. Results in patients with sustained and paroxysmal hypertension and multiple endocrine neoplasia

In a series of 53 pheochromocytoma patients operated on at Sahlgren's Hospital during 1956-82, a positive linear correlation is established between the 24-hour urinary excretion of vanilmandelic acid (mumol/24 h) and tumour mass (g). A similar correlation was found between the excretion of metanephrines and tumour mass in 33 subjects. The patients were subgrouped according to their type of hypertension. A statistically significant correlation between vanilmandelic acid excretion and tumour mass persisted in groups IA (sustained hypertension without attacks), IB (sustained hypertension with attacks), and II (paroxysmal hypertension) but not in group III (miscellaneous patients). There was also a correlation between metanephrine excretion and tumour mass in groups IB (n = 8) and II (n = 12). In 10 patients with the syndrome of multiple endocrine neoplasia, a positive correlation was found between tumour mass and the excretion of vanilmandelic acid, metanephrines and adrenaline.

Phaeochromocytoma with normal urinary catecholamines: the potential value of urinary free metadrenalines

BACKGROUND

Normal urine catecholamine values in patients with phaeochromocytoma is an occasional finding and may lead to a missed diagnosis. Additional urinary free metadrenaline analysis may be of value in this situation.

METHODS

In addition to vanillylmandelic acid, homovanillic acid and the catecholamines, urinary free normetadrenaline (fNMA) and free metadrenaline (fMA) were measured. This report describes six confirmed cases of phaeochromocytoma showing normal urinary catecholamine output and compares fMA results and tumour size with other confirmed cases where the urine catecholamines were increased.

RESULTS

Urine catecholamines in these patients with, on average, smaller tumours, were all normal. Urinary fNMA and fMA were available on five patients, and were increased in three. The data suggest that, unlike the catecholamines, urinary fNMA and fMA could be a useful predictor of tumour size.

CONCLUSION

The inclusion of fNMA and fMA in the test profile is likely to be of additional benefit in tumour detection, particularly when catecholamines or other metabolites are normal.

[The diagnosis of atypical pheochromocytoma: a challenge for the biologist as well]

Biological diagnosis of pheochromocytoma is relatively easy in those cases releasing great amounts of catecholamines with strong clinical features; instead, diagnosis could be more problematic in atypical or asymptomatic familial pheochromocytoma with small tumors secreting low catecholamine amounts. Several plasma and urine adrenergic markers must be used to confirm the clinical suspicion. We have discussed the biological data of three totally asymptomatic pheochromocytomas (cases no 2, 3, 4) and one case with a very discrete clinical manifestation (no 1). Three patients had very small tumors (4, 7 and 25 g) secreting preeminently adrenaline, one patient had a 45 g adrenal incidentaloma without clinical expression. Our study shows that, in these special cases, except for an inconstant increase of adrenaline, plasma and urine catecholamines and urine VMA can be normal. The most useful markers are plasma and urine methoxyamines. However, plasma methoxyamines are the most sensitive because their increase over reference values is by far greater than in urines. Several factors may explain these findings: a low tumoral secretion, the nature of the released amine, the short half-life of catecholamines in plasma and, in some cases, the involvement of intratumoral catecholamine metabolism. Analysis of the ratio NMN/MN in plasma provides an additional diagnosis tool to reveal adrenaline secretion abnormalities.

Lack of uniformity in the clinical approach to the interpretation of urinary catecholamines and their metabolites

A study of the case notes from 101 of the 113 instances where at least one of the results was abnormal from the analysis of 24 hr urinary collections for noradrenaline, adrenaline, and dopamine and their metabolites 4-hydroxy-3-methoxy-mandelic acid (HMMA) and homovanillic acid (HVA) in screening for phaeochromocytomas in hospitals affiliated to the Royal College of Surgeons in Ireland Medical School from a total of 199 false positives from all sources shows that 51% had a second sample, 33% had ultra sound, 12% had a CT scan, 6% had an 131I metaiodobenzylguanadine (MIBG) scan, 40% had no imaging performed and in 5% the reports were not received by the referring medical team. The 12 sets of data where case notes could not be retrieved were disregarded. Of the 22 patients with one or more biochemical value greater than twice the upper reference range, 8 had not, by our criteria had a phaeochromocytoma positively excluded. The sensitivity and specificity for phaeochromocytoma diagnosis for the free catecholamines together was 82% and 88.4%; for HMMA 60% and 95.8%; and for catecholamines and HMMA together 82% and 93.2% respectively. A protocol which includes repeat samples where results are abnormal and the appropriate use of diagnostic imaging should be systematically pursued to minimise false negative diagnoses.

The impact of recent advances in diagnostic technology on the clinical presentation of phaeochromocytoma

OBJECTIVE

To examine the impact of recent advances in diagnostic technology on the spectrum of clinical and biochemical features of patients presenting with a new diagnosis of phaeochromocytoma.

DESIGN

A retrospective review of the clinical and biochemical features of patients diagnosed by our laboratory as having phaeochromocytoma within a 27-month period up to December, 1990. Noradrenaline, adrenaline and dihydroxyphenylglycol were assayed in 24-hour urine specimens (19 patients) or plasma (1 anuric patient) by gas chromatography/mass spectrometry.

SETTING

A tertiary level chemical pathology department.

PATIENTS

Twenty patients with a new diagnosis of phaeochromocytoma.

RESULTS

The classic, episodic adrenergic symptoms traditionally associated with phaeochromocytoma were absent in 9 of the 20 patients (45%). "Atypical" phaeochromocytoma presented as a mass on computed tomography imaging (6 patients, 30%), "phaeochromocytoma crisis" (4 patients, 20%) or family screening (1 patient, 5%). Excessive adrenaline production was found in 11 patients (55%) and six (30%) had predominantly adrenaline-secreting tumours. The urinary noradrenaline:dihydroxyphenylglycol ratio was raised in all nine patients with predominantly noradrenaline-secreting tumours but was not raised in nine out of ten patients with adrenaline-secreting phaeochromocytoma. Adrenaline excretion was significantly correlated with tumour size (r = 0.8; P less than 0.05).

CONCLUSIONS

Advances in diagnostic technology, particularly specific adrenaline assays and computed tomography, have made possible the early diagnosis of patients with phaeochromocytoma presenting in ways previously thought to be uncommon. All patients with adrenal masses noted incidentally on CT scan should be investigated for phaeochromocytoma. Adrenaline-secreting tumours are common and both noradrenaline and adrenaline should be assayed in all patients investigated for phaeochromocytoma.

Quality assurance for biogenic amines with authentic patient specimens

The measurement of biogenic amines and metabolites is essential for diagnosis and follow-up of neural crest tumors. A Quality Assurance programme involving the distribution of urine specimens obtained from patients with neural crest and related tumors was conducted by the Australian Association of Clinical Biochemists' Working Party on Biogenic Amines in 1988. Fifty laboratories participated in the programme and measured a number of analytes with a variety of methods. These included high performance liquid chromatography with electrochemical detection (HPLC-EC), spectrophotometry, fluorescence, fluorescence polarization immunoassay (Abbott TDX) and gas chromatography--mass spectroscopy (GC-MS). The results of this survey indicated that fluorimetric methods for catecholamines are unreliable as they are subject to interference particularly by Labetalol. Twice as many laboratories utilized catecholamines rather than metanephrines for detection of pheochromocytoma. 5-HIAA appears to be the analyte measured with the least accuracy, particularly with spectrophotometric methods of analysis. Several laboratories would have failed to diagnose some neural crest tumors and need to improve their performance.

The development of a catechol enzyme electrode and its possible use for the diagnosis and monitoring of neural crest tumours

A catechol enzyme electrode is described, in which a Clark-type oxygen electrode is coupled to immobilised polyphenol oxidase in albumin cross linked with glutaraldehyde on a dialysis membrane. Electrode calibration, response time, pH response profile, stability, detection limit and selectivity are evaluated and the feasibility of using the electrode for the measurement of catecholamines in the urine of patients with neural crest tumours is assessed.

An automated method for the analysis of urinary free catecholamines using ASTED and high-pressure liquid chromatography

A high-pressure liquid chromatography procedure for the measurement of free catecholamines in urine is described. 'On-line' sample preparation using a cartesian robot combined with the ASTED process ensures minimal operator intervention and reduced costs.

Simultaneous quantitation of catecholamines and O-methylated metabolites in urine by isocratic ion-pairing high-performance liquid chromatography with amperometric detection

A simple high-performance liquid chromatographic procedure was developed for the simultaneous determination of catecholamines and metanephrines in urine. One-step sample preparation was achieved with Bio-Rex 70 ion-exchange resin. The extract was assayed on a C18 reversed-phase column. Dihydroxybenzylamine was used as an internal standard. The eluent was monitored by an electrochemical detector with an oxidation potential of +0.85 V. The use of 1-heptanesulphonic acid in the mobile phase permitted the separation of norepinephrine, epinephrine, dopamine, normetanephrine and metanephrine in a single chromatogram. The corresponding detection limits were 5, 9, 14, 10 and 30 nmol/l, respectively. For the between-day precision, the coefficients of variation at physiological and pathological concentrations were less than 11%. Compounds with similar chemical structures and drugs commonly prescribed for the treatment of hypertension were assayed and found not to cause interferences in the chromatogram. The assay is reliable and is suitable for the analysis of clinical specimens. Reference values were established for normotensive Chinese patients with no neurological or endocrine disorders and also for patients suffering from essential hypertension.

Influence of oral contraceptive treatment on blood pressure and 24-hour urinary catecholamine excretion in smoking as compared with non-smoking women

Microgynon-30 was administered to 15 smoking (group B) and 14 non-smoking young women (group A) for a period of 4 months. Prior to the institution of treatment supine blood pressure and daily urinary catecholamine excretion (DUCE) were measured in both groups of patients. Both values were elevated in group B in comparison with group A. Treatment with Microgynon-30 for 4 months induced a significant increase in DUCE in both groups, the increase being most marked in group B (p less than 0.0004). The increased catecholamine excretion accompanied small non-significant elevations in blood pressure. It is concluded that treatment with low-dosage estrogen oral contraceptives produces a significant increase in daily catecholamine excretion, especially in patients who smoke.

Routine determination of urinary free catecholamines by high-performance liquid chromatography with electrochemical detection

A simple and reliable high-performance liquid chromatographic method is described for the routine determination of the free catecholamines (norepinephrine, epinephrine and dopamine) in urine. The catecholamines are isolated from urine samples using small affinity chromatography columns prepacked with immobilised m-aminophenylboronic acid, separated by ion-pair reversed-phase liquid chromatography and quantified by electrochemical detection. Total analysis, including sample preparation time, is achieved in less than 30 min with analytical recoveries of 92-96% for all three catecholamines. Long-term stability and reproducibility of the liquid chromatographic system is attained by selection of optimised conditions for chromatographic separation with a formate mobile phase and produces detection limits of 1.4, 1.8 and 2.2 nmol/l for norepinephrine, epinephrine and dopamine, respectively, in urine samples and day-to-day coefficients of variation of less than 6%. Furthermore, the affinity isolation gels can be reused a minimum of ten times providing a rapid and cost-effective means of sample preparation.

Simultaneous determination of the major acidic metabolites of catecholamines and serotonin in urine by liquid chromatography with electrochemical detection after a one-step sample clean-up on Sephadex G-10; influence of vanilla and banana ingestion

A simple method is described for the simultaneous determination of vanilmandelic acid (VMA), 3,4-dihydroxyphenylacetic acid (DOPAC), 5-hydroxyindole-3-acetic acid (5-HIAA) and homovanillic acid (HVA) in urine. The compounds are isolated by a one-step sample clean-up on Sephadex G-10, separated by ion-pair reversed-phase liquid chromatography and detected electrochemically. A single analysis is completed within 65 min. Sample clean-up did not cause losses of the compounds of interest. The detection limits in urine were 0.4, 0.8, 1.0 and 1.6 mumol/l for VMA, DOPAC, 5-HIAA and HVA, respectively. 3,4-Dihydroxymandelic acid and vanillic acid (VA) were also detectable, but, under the chromatographic conditions used, they were not resolved from interfering components. VA and 5-HIAA could be analysed separately in the Sephadex G-10 eluate if more restrictive sampling conditions were used. Ingestion of bananas caused an increase of VMA, DOPAC, 5-HIAA and HVA in 24-h urine. After ingestion of vanilla an increased excretion of VA was observed, while the excretion of VMA, DOPAC and HVA was unaffected.

Urinary free catecholamines--diagnostic application of an HPLC technique to the investigation of neural crest tumours

Experience in the use of an in-house urinary free catecholamine assay for the investigation of possible neural crest tumours in a District General Hospital laboratory is described. Elevated excretion of catecholamines and vanillylmandelic acid was found in a number of cases including phaeochromocytoma and neuroblastoma. These as well as several other situations in which elevated catecholamine and vanillylmandelic acid values were found are discussed.

A comparison of dopamine and homovanillic acid excretion, as prognostic indicators in malignant phaeochromocytoma

The urinary excretion of dopamine and its metabolite homovanillic acid (HVA) were compared in 15 patients with malignant phaeochromocytoma. Six patients with increased dopamine and HVA excretion had disseminated malignancy and the poorest prognosis. Four patients with increased urinary dopamine levels but normal HVA excretion also had widespread metastases and poor prognosis. The best prognosis was for 5 patients who had normal excretion of dopamine and HVA, and minimal disease. When dopamine and HVA excretion were considered separately, it was found that duration of survival was significantly better for patients with normal dopamine excretion than those with increased dopamine excretion (p less than 0.003). There was no significant difference in survival time between patients with normal and increased HVA excretion. In this study dopamine excretion appeared to be a more discriminating biochemical index of malignancy, prognosis and disease progression than HVA excretion.

Direct concurrent measurement of urinary vanillylmandelic acid, 5-hydroxyindoleacetic acid and homovanillic acid by HPLC. Three methodologies compared

Three different direct HPLC methods for the determination of 3-methoxy-4-hydroxymandelic acid (VMA, vanillylmandelic acid), 5-hydroxyindoleacetic acid (5-HIAA) and 3-methoxy-4-hydroxyphenylacetic acid (HVA, homovanillic acid) in urine were compared: two spectrofluorometric methods, applying discontinuous gradients, and one serial coulometric linear gradient method. The imprecision study (n = 6) revealed comparable coefficients of variation (CV), intra-assay ranging 1.4-11.1%, and inter-assay ranging 5.9-11.8% for physiological and moderately elevated levels of VMA, 5-HIAA and HVA. All methods showed good linearities up to 100 mumol/L for each of the three compounds studied. Analytical recoveries were 97-114% for VMA, 87-103% for 5-HIAA, and 80-95% for HVA. Recoveries were not dependent on urinary relative densities in the range 1.010-1.030 kg/L or on protein content (prior to acidification) in the range 0.1-3 g/L, or on the pH of conservation in the range 2-5 or on storage temperature in the range -20 - +22 degrees C for three weeks. The distributed-sample comparison revealed acceptable correlations and clinically unimportant accuracy differences between the methods. It is concluded that direct fluorometric and electrochemical HPLC methods can be used in the determination of major catecholamine and serotonin metabolites in human urine for clinical diagnosis and follow-up of neural crest and carcinoid tumours.

The influence of short-term estrogen replacement therapy (ERT) on the blood pressure and daily urinary catecholamine excretion in a small group of post-menopausal women

The blood pressure and daily urinary catecholamine excretion were examined in nineteen non-smoking post-menopausal women, receiving estrogen replacement therapy for a period of 4 months. The estrogens administered consisted of 17 beta-estradiol combined with estriol and norethisterone acetate administered sequentially (Trisequens, Novo, Denmark). Before the institution of treatment, the blood pressure and urinary catecholamine excretion were normal. After a period of 4 months, no change in blood pressure was observed. However, a marked and significant increase in daily urinary catecholamine excretion was noticed (72.3 +/- 18.96 micrograms/day to 102.0 +/- 26.0 micrograms: p less than 0.01). The pathogenetic implications of this increase are discussed.

The assay of 4-hydroxy-3-methoxymandelic acid in urine by HPLC with electrochemical detection using bonded-phase silica sorbents for rapid, simple and selective extraction

A method is reported for the determination of 4-hydroxy-3-methoxymandelic acid (HMMA) by HPLC with electrochemical detection. The preparation of sample prior to HPLC has been studied and an efficient and selective extraction procedure described. Bonded-phase silica extraction columns and a vacuum manifold were used for the simple and rapid processing of batches of urine samples. Combining a reverse-phase C18 and an anion exchange column ensures selective isolation of HMMA. This simplified greatly the subsequent chromatography. The method was combined into a simple scheme for the routine analysis of urine HMMA, catecholamines and 5-hydroxyindole-3-acetic acid. The HPLC was standardised such that a single mobile phase was used with minor modification for each of the assays.

Determination of free and total catecholamines and salsolinol in urine by ion-pair reversed-phase liquid chromatography with electrochemical detection after a one-step sample clean-up

A simple method is presented for the routine determination of free and total catecholamines and salsolinol in urine. For the analysis of total catecholamines and salsolinol, the urine samples are first hydrolysed. The compounds are isolated by a one-step sample clean-up by cation-exchange chromatography and separated by ion-pair reversed-phase liquid chromatography and detected electrochemically. The method is suited for routine analysis. Pretreatment of ten samples for the high-performance liquid chromatographic analysis of free and total catecholamines and salsolinol is carried out in 4 h. A single analysis is completed in 30 min. The absolute losses of the compounds were less than 10%, except for epinephrine (20%). The detection limits were 0.9, 2.4, 4.8 and 6 nmol/l for norepinephrine, epinephrine, dopamine and salsolinol, respectively, in native urine. The values were twice as high for hydrolysed urine. The sample clean-up appears to be rather specific: apart from catecholamines and salsolinol, only those structurally related amines that contain a vicinal hydroxyl group are isolated.

Influence of pre-operative treatment with phenoxybenzamine on the incidence of adverse cardiovascular reactions during anaesthesia and surgery for phaeochromocytoma

The influence of pre-operative treatment with the alpha-adrenoceptor blocking agent, phenoxybenzamine, on the incidence of adverse cardiovascular reactions during anaesthesia and surgery for phaeochromocytoma was evaluated in a series of 62 patients. Fifty-one of them received pre-operative treatment with phenoxybenzamine and eight of these were also treated with beta-adrenoceptor blocking agents. The median final daily dose of phenoxybenzamine was 160 mg and the median period of treatment 23 days. The evening before surgery and in the early morning on the day of surgery, intravenous infusion of phenoxybenzamine was given to 42 of the patients. Eleven patients operated on between 1956 and 1963 received no specific pre-operative treatment and served as a reference group. The alpha-adrenoceptor blocking treatment resulted in a considerably smoother peroperative course, as evidenced by a statistically significant reduction in the incidence of excessive blood-pressure variations. The blockade was not complete since 69% of the patients had systolic peaks greater than 175 mmHg during surgery. Pre-operative blood transfusions did not significantly affect the incidence of hypotensive episodes. Pre-operative beta-adrenoceptor blockade did not reduce the incidence of peroperative arrhythmia. On the basis of our experience, we recommend that all phaeochromocytoma patients be treated pre-operatively with alpha-adrenoceptor blocking agents.

A simple, optimised and rapid assay for urinary free catecholamines by HPLC with electrochemical detection

A rapid method is described for the determination of urinary free catecholamines by HPLC with electrochemical detection. Optimised and equilibrium assay conditions are assessed for sample preparation, separation and detection. Catecholamine stability is maintained during the assay procedure by the addition of a combined reducing agent. Variability in recovery between aqueous standards and urine samples is minimised by dilution of samples with a concentrated Tris buffer solution. Ethyl acetate washing of an acid eluate is performed after and not before an alumina adsorption step in order to make the procedure as simple and rapid as possible. The method is evaluated and has thus far identified two cases of phaeochromocytoma and one case of neuroblastoma.