Pheochromocytoma: state-of-the-art and future prospects

Adrenocortical carcinoma posing as a pheochromocytoma: a diagnostic dilemma

Adrenocortical carcinoma (ACC) is a malignant tumour arising from the adrenal cortex, whereas pheochromocytoma is a tumour of the adrenal medulla with occasional presence at extra-adrenal sites. Most of the adrenocortical tumours present clinically with Cushing's syndrome and signs of virilization due to over-production of the respective hormones. It is, however, rare for an adrenocortical tumour to present clinically as a pheochromocytoma. We report the case of a 45-year-old female presenting with clinical symptoms and signs of pheochromocytoma and investigations that resulted in a diagnostic dilemma. The histopathological examination confirmed the presence of ACC after the tumour was excised. This phenomenon was due to the presence of neuroendocrine features of ACC referred to, as a pseudo-pheochromocytoma with extremely limited data in the literature.

Perirenal (18)F-FDG Uptake in a Patient with a Pheochromocytoma

Increased (18)F-fluorodeoxyglucose (FDG) uptake of brown fat on (18)F-FDG positron emission tomography (PET) originating from physiological activation is a common incidental finding and is usually located in the neck, shoulder, and supraclavicular areas. We present a case of an incidental pheochromocytoma showing diffusely increased (18)F-FDG uptake in bilateral perirenal fat tissue as well as supraclavicular and paravertebral fat tissue on (18)F-FDG PET/CT. The patient had no clinical symptoms except hypertension, and a pheochromocytoma was confirmed in a postsurgical specimen. A pheochromocytoma should be considered a cause in cases of increased (18)F-FDG uptake of perirenal brown fat.

Anti-hypertensive treatment in pheochromocytoma and paraganglioma: current management and therapeutic features

Pheochromocytoma (PH) and paraganglioma (PG) are neuroendocrine neoplasms arising from chromaffin cells of the adrenal medulla and the sympathetic ganglia, respectively. Although are unusual cause of hypertension (HT) accounting for at most 0.1-0.2 % of cases, they may lead to severe and potentially lethal hypertensive crisis due to the effects of the released catecholamines. However, both PH and PG may be asymptomatic as ~30 % of subjects are normotensive or have orthostatic hypotension and in these cases the 24 h ambulatory blood pressure (BP) monitoring is an important toll to diagnose and treat HT. HT treatment may be difficult when PH or PG occurs in pregnancy or in the elderly subjects and in these cases a multidisciplinary team is required. When surgical excision is mandatory the perioperative management requires the administration of selective α1-adrenergic blocking agents (i.e., doxazosin, prazosin or terazosin) followed by a β-adrenergic blockade (i.e., propranolol, atenolol). This latter should never be started first because blockade of vasodilatory peripheral β-adrenergic receptors with unopposed α-adrenergic receptor stimulation can lead to a further elevation of BP. Although labetalol is traditionally considered the ideal agent due to its α- and β-adrenergic antagonism, experimental studies do not support its use in this clinical setting. As second regimen, the administration of vasodilators as calcium channel blockers (i.e., nicardipine, nifedipine) may be required to control BP. Oral and sublingual short-acting nifedipine are potentially dangerous in patients with hypertensive emergencies and are not recommend. The latest evidences into the diagnosis and treatment of hypertensive crisis due to PH and PG are reviewed here.

Evaluation of sonographic features for patients with urinary bladder paraganglioma: a comparison with patients with urothelial carcinoma

The goals of the work described here were to analyze the ultrasonographic characteristics of urinary bladder paraganglioma and to evaluate the use of ultrasonography (US) in diagnosis. Ten patients with bladder paraganglioma (3 males, 7 females) and 51 patients with urothelial carcinoma (37 males, 14 females) were enrolled. Ultrasonographic characteristics as well as clinical features were analyzed. Patients with urothelial carcinoma were significantly older than those with paraganglioma (62.9 y vs. 48.1 y, p = 0.001). The patients with paraganglioma had higher average systolic blood pressure than those with urothelial carcinoma (146.7 mm Hg vs. 130.7 mm Hg, p = 0.012). All bladder paragangliomas were solitary, and 40% were located on the dome. There was a statistically significant difference in location of lesions between the bladder paraganglioma and urothelial carcinoma groups (p = 0.014). The longest diameters in 80% of the bladder paragangliomas were in the range 1.1-3.0 cm; 60% were hypoechoic, and 40% were located in the submucosa of the bladder. Color Doppler revealed that 40% of the bladder paragangliomas were highly vascular. One patient with paraganglioma and four patients with urothelial carcinoma underwent contrast-enhanced ultrasound, which revealed rapid contrast enhancement and slow wash-out, with a non-enhanced area. Contrast-enhanced ultrasound of urothelial carcinomas revealed rapid homogeneous enhancement and variable wash-out patterns. Pre-operative ultrasonography detected all neoplasms of the urinary bladder in the 10 patients with pathologically confirmed paraganglioma, but made the correct diagnosis in only 2 cases (20%). Although there is overlap in US findings among different diseases, solitary, submucosal masses arising on the dome may be the key US imaging characteristic for bladder paraganglioma.

Functional paraganglioma

Paraganglioma are tumours arising from neural crest cells of the sympathetic and parasympathetic paraganglia. Functional paraganglioma presents with symptoms of catecholamine excess that includes hypertension, flushing, diaphoresis, etc. Non-functional paraganglioma are usually found incidentally during imaging studies. Early diagnoses of functional paraganglioma are important because their removal is often curative. We present the case of a young man who presented with hypertensive crisis and severe headache, who was later found to have functional paraganglioma.

Pheochromocytoma: a review

Pheochromocytomas are catecholamine producing neuroendocrine tumors that can be adrenal or extra-adrenal in origin. The classic symptoms of pheochromocytoma are headache, palpitation, anxiety and diaphoresis and the tumor can occur at any age with equal gender distribution. In patients with an established mutation or hereditary syndrome the condition may manifest at a younger age than in those with sporadic disease. Pheochromocytoma can be associated with certain genetic syndromes such as multiple endocrine neoplasia type 2 (MEN 2), neurofibromatosis (NF) and von Hippel-Lindau (VHL) syndrome. Pheochromocytoma is diagnosed with biochemical confirmation of hormonal excess followed by anatomical localization (CT or MRI). The mainstay of definitive therapy is surgical resection. In this review, we discuss in detail about the symptomatology, diagnosis, genetic aspects and management of pheochromocytoma.

Plasma free metanephrines in the diagnosis of pheochromocytoma: diagnostic accuracy and strategies for Japanese patients

Measuring the levels of the plasma free metanephrines (PFMs) represents a recently developed and promising test for the diagnosis of pheochromocytoma in the United States and Europe. As this test has not yet been evaluated in Japan, it is necessary to evaluate the diagnostic efficacy of measuring the levels of PFMs compared with the standard measurement of the urinary excretion of metanephrines (uMNs) whose reliability is well established to detect of pheochromocytoma. A total of 101 Japanese subjects clinically suspected of having pheochromocytoma in were included in this study. Subsequently, we prospectively measured the PFMs levels in all patients, compared with those of biochemical markers of the catecholamine secretion and metabolisms in the plasma and urine. All subjects with adrenal tumors underwent tumor excision. Data were available for 84 of the 101 patients, 47 of whom had histopathologically proven pheochromocytoma and 37 were finally diagnosed with non-pheochromocytoma. The results of comparisons in the accuracy of measurement for diagnosis of pheochromocytoma between PFMs and the urinary excretion of metanephrines (uMNs) were 0.980 VS 0.951 for AUC of receiver operatorating characteristic (ROC) curve, 0.957 VS 0.894 for sensitivity, and 0.973 VS 0.946 for specificity, respectively. Although the differences were small, the results of our study definitely demonstrated that measurement of PFMs was not inferior to standard urinary metanephrines (uMNs) measurement, which is established to be the most reliable biochemical method to detect pheochromocytoma. This study clearly shows measuring the PFMs levels to be a reliable and efficient method for diagnosing pheochromocytoma in Japanese patients, as demonstrated in previous reports.

Adrenal incidentaloma imaging - the first steps in therapeutic management

The term “adrenal incidentaloma” refers to clinically unapparent adrenal mass detected during imaging examination performed for reasons other than the evaluation of adrenal glands. These tumors must be carefully examined in order to assess the indications for surgical treatment. The main method of finding evidence of potential malignancy in these lesions is computed tomography (CT), before and after i.v. contrast media enhancement. Density of a malignant lesion is higher than 10 HU and the relative percentage washout is less than 40% at 10 min. Other useful methods utilized in tumor assessment, include magnetic resonance imaging (MRI), scintigraphy techniques (SPECT) and PET. Basal hormonal investigations include urine and plasma catecholamines with their metabolites, plasma cortisol before and after dexamethasone administration, plasma renin activity and aldosterone level. Cases not suitable for surgery should be followed with repeat imaging techniques and hormonal testing at the recommended 6, 12, and 24 months. Surgery should be performed when tumor growth rate exceeds 0,8 cm per year.

Unexpected small urinary bladder pheochromocytoma: a nonspecific presentation

Objectives. Pheochromocytoma of the urinary bladder is an extremely rare tumor that typically presents with a hypertensive crisis during micturition. Preoperatively, it may be misdiagnosed due to nonspecific symptomatology, physical, and radiologic findings. Method. We report a case of unsuspected small pheochromocytoma which was incidentally found by CT scan and confirmed by the histological aspects after transurethral resection in a 63-year-old woman. Here, we have described the clinical presentation, physical findings, laboratory investigations, and treatment provided in our case. We have also included radiological images and histopathology slides with input from both radiologists and pathologists. Surgical management and postoperative follow-up are discussed, as are details of previous published data. Results. After undergoing surgical treatment (transurethral resection), our patient is asymptomatic, with complete resolution of her pathology. Conclusion. Diagnosis is difficult before histopathological examination and should be considered in patients with no risk factors for usual bladder tumor. Our purpose is to raise clinician's awareness for this condition so that they will be more likely to diagnose it. This will facilitate prompt diagnosis and treatment and especially prevent complications due to pheochromocytoma which may be severe.

Phaeochromocytoma crisis: two cases of undiagnosed phaeochromocytoma presenting after elective nonrelated surgical procedures

Phaeochromocytoma is a catecholamine producing tumour and an uncommon cause of hypertension. We present two cases of relatively asymptomatic individuals, in which previously undiagnosed phaeochromocytoma was unmasked by elective nonadrenal surgical procedures, manifesting as postoperative hypertensive crisis and subsequent cardiogenic shock. The initial management in intensive care is discussed, in addition to the clinical and biochemical diagnostic challenges present. Successful adrenalectomy was performed in each case.

Intraoperative management of patients with incidental catecholamine producing tumors: A literature review and analysis

Context:

Present knowledge about intraoperative management, morbidity, and mortality of patients with undiagnosed catecholamine-producing tumors is mostly based on published case reports and anecdotal evidence.

Aims:

The aim was to summarize the management and outcomes of reported cases and analyze for practice patterns, deduct useful management recommendations as applicable.

Settings and Design:

The Medline database was searched with specific keywords for the period of 1988-2010 for cases of incidental pheochromocytomas and paragangliomas.

Materials and Methods:

Case reports in the English language with a postoperative diagnosis of pheochromocytoma and paraganglioma by histopathology were included. Systematic data extraction from case reports was done.

Statistical analysis used:

Descriptive statistics were applied.

Results:

Of 823 retrieved records, 62 case reports met inclusion criteria. Hemodynamic instability occurred primarily during mass manipulation/intraoperatively (52%, n = 32) and induction/laryngoscopy (18%, n = 11). In cases reporting specific antihypertensive treatments, nitrates (67%, n = 30) represented the majority of medications used, followed by beta-blockers (47%, n = 21). Alpha receptor blockers were administered in 33% (n = 15). The perioperative mortality was 8% (n = 5), and none of these patients received intraoperative alpha blockade. A catecholamine-secreting tumor was suspected intraoperatively in 26% of cases.

Conclusions:

The perioperative mortality based on the reviewed cases of incidental catecholamine producing tumors was less than would traditionally be expected. Intraoperative alpha receptor blockade to treat hypertension was reported in 33% of cases, and none of the patients with a fatal outcome had received it. A higher intraoperative index of suspicion and a lower threshold to consider alpha blocking medications for severe intraoperative hypertension may improve outcomes.

Intraoperative management of patients with incidental catecholamine producing tumors: A literature review and analysis

CONTEXT

Present knowledge about intraoperative management, morbidity, and mortality of patients with undiagnosed catecholamine-producing tumors is mostly based on published case reports and anecdotal evidence.

AIMS

The aim was to summarize the management and outcomes of reported cases and analyze for practice patterns, deduct useful management recommendations as applicable.

SETTINGS AND DESIGN

The Medline database was searched with specific keywords for the period of 1988-2010 for cases of incidental pheochromocytomas and paragangliomas.

MATERIALS AND METHODS

Case reports in the English language with a postoperative diagnosis of pheochromocytoma and paraganglioma by histopathology were included. Systematic data extraction from case reports was done.

STATISTICAL ANALYSIS USED

Descriptive statistics were applied.

RESULTS

Of 823 retrieved records, 62 case reports met inclusion criteria. Hemodynamic instability occurred primarily during mass manipulation/intraoperatively (52%, n = 32) and induction/laryngoscopy (18%, n = 11). In cases reporting specific antihypertensive treatments, nitrates (67%, n = 30) represented the majority of medications used, followed by beta-blockers (47%, n = 21). Alpha receptor blockers were administered in 33% (n = 15). The perioperative mortality was 8% (n = 5), and none of these patients received intraoperative alpha blockade. A catecholamine-secreting tumor was suspected intraoperatively in 26% of cases.

CONCLUSIONS

The perioperative mortality based on the reviewed cases of incidental catecholamine producing tumors was less than would traditionally be expected. Intraoperative alpha receptor blockade to treat hypertension was reported in 33% of cases, and none of the patients with a fatal outcome had received it. A higher intraoperative index of suspicion and a lower threshold to consider alpha blocking medications for severe intraoperative hypertension may improve outcomes.

Adrenal venous catecholamine concentrations in patients with adrenal masses other than pheochromocytoma

The aim of this study was to retrospectively examine adrenal venous catecholamine concentrations and related indices in non-pheochromocytoma patients and to estimate from the obtained results whether measurements of adrenal venous catecholamine concentrations by adrenal venous sampling (AVS) are useful for localizing adrenal pheochromocytoma. The study population comprised 15 patients in whom AVS was performed for evaluation of adrenal non-pheochromocytoma masses (primary aldosteronism, n = 8; Cushing syndrome, n = 5; non-hyperfunctioning tumor, n = 2) without hormonal intervention and was successful in bilaterally judging adrenal vein to infra-renal inferior vena cava cortisol ratios as >3.0. Wide ranges of catecholamine concentrations were seen for both right (epinephrine, 35-175,821 pg/ml; norepinephrine, 115-32,102 pg/ml; dopamine, 9-232 pg/ml) and left (epinephrine, 16-27,251 pg/ml; norepinephrine, 155-9,267 pg/ml; dopamine, 5-234 pg/ml) adrenal veins. High- to low-side adrenal vein concentration ratios also showed wide ranges of up to 779 for epinephrine, 22.5 for norepinephrine, and 7.8 for dopamine. Adrenal venous catecholamine concentrations obtained by AVS and simple comparisons between bilateral adrenal veins might not be useful to localize adrenal pheochromocytoma, as wide variations in concentrations and high- to low-side adrenal vein concentration ratios were noted in patients with adrenal non-pheochromocytoma.

Adrenal tumours are more predominant in females regardless of their histological subtype: a review

OBJECTIVES

Adrenal tumours are a heterogeneous group of rare tumours. The aim of this article was to critically review gender-specific differences in the incidence, prognosis and symptoms of the different subtypes of adrenal tumours.

METHODS

Data acquisition regarding gender differences in adrenal tumours was performed using MEDLINE searches with combinations of the following keywords: adrenal tumours, gender, sex differences, adrenocortical carcinoma, pheochromocytoma, incidentaloma, risk factors and genetic aspects.

RESULTS

Data are scarce in the literature concerning the effects of gender on adrenal lesions. Although the incidence of most types of tumours (other than breast cancer and other gender-related tumours) is higher in men than in women, evidence suggests that adrenal tumours (i.e. incidentalomas, adrenal carcinomas, oncocytomas and adrenal cysts) are more frequent in women than in men. In addition, female patients have significantly increased numbers of self-reported signs and symptoms of pheochromocytoma than male patients, irrespective of biochemical phenotype and tumour presentation. Relatively little research has been performed examining the reasons for these disparities. However, hormonal interactions involving complex adrenal, endocrine and neurocrine functions together with variations in hormonal receptor sensitivity have been hypothesised to be involved.

CONCLUSION

Gender differences exist in the incidence and symptoms of several subtypes of adrenal tumours. The reasons for these disparities are not well established. In addition to epidemiological data, these results need to be further investigated to better understand the role of genetic and hormonal predispositions in the development, behaviour and aggressiveness of adrenal tumours.

Cardiac complications as initial manifestation of pheochromocytoma: frequency, outcome, and predictors

OBJECTIVE

To examine the frequency, outcome, and clinical predictors of cardiac complications as the initial manifestation of pheochromocytoma.

METHODS

The medical records of all 76 patients with pheochromocytoma or functional paraganglioma treated at Cedars-Sinai Medical Center, Los Angeles, California, from 1995 to 2011 were reviewed. The patients initially presenting with cardiac complications were identified, and their clinical, laboratory, and imaging characteristics were compared with those of the patients presenting with other complaints, especially hypertension and adrenal mass.

RESULTS

Of the 76 patients, 9 (12%) presented with the following: 2 with acute heart failure, 1 with left ventricular thrombus, 3 with myocardial infarction, and 3 with severe arrhythmia. Failure to diagnose pheochromocytoma resulted in unnecessary invasive interventions in 2 patients. Recovery of cardiac function was excellent after resection of the tumor in all patients. In comparison with the 67 patients presenting with other complaints, the 9 with cardiac complications had similar demographics and cardiac risk factors but harbored larger tumors (6.7 ± 0.8 cm versus 4.4 ± 0.3 cm; P = .015) and exhibited higher biochemical marker levels (23.9 ± 9.0-fold versus 11.3 ± 2.4-fold; P = .082), longer corrected QT interval (473 ± 8 ms versus 443 ± 6 ms; P = .015), and lower ejection fraction (43% ± 8% versus 66% ± 2%; P = .002).

CONCLUSION

In this study, 12% of patients with pheochromocytoma initially presented with cardiac complications. Patients with large tumors and high levels of biochemical markers were more likely to develop cardiac injury. Our results confirm that the presence of pheochromocytoma should be ruled out in patients with cardiac diseases and features suggesting pheochromocytoma so that unnecessary interventions can be avoided and cardiac recovery can be achieved.

Clinical experience with pheochromocytoma in a single centre over 16 years

BACKGROUND

Pheochromocytoma and paraganglioma are rare tumours of neuroectodermal origin. Pheochromocytoma occurs in 0.1-2% of people with hypertension, while the incidence rises to 4-5% in patients with incidental adrenal mass.

AIM

To analyse the presentation, diagnosis and localization, pathology, molecular genetic aspects, surgical management and long-term outcome of a large series of patients with pheochromocytoma referred to a single centre.

METHODS

From 1992 to 2008, we observed 91 patients with pheochromocytoma, 70 (77%) with the sporadic form and 21 (23%) with the hereditary form. In the group with the hereditary form, the mean age at diagnosis was significantly lower than the mean age of the group with the sporadic form (38 vs 48 years; p < 0.001).

RESULTS

Eighty (88%) patients with pheochromocytoma were symptomatic and the classical triad of palpitations, headache and diaphoresis was present in 30% of patients. In 12% of patients, the pheochromocytoma was discovered during radiological images (adrenal incidentaloma). The unilateral adrenal localization was observed in 78% of patients, bilateral in 15% and extra-adrenal in 7% of patients. All pheochromocytoma patients underwent surgical procedure and the laparotomic approach was used in 49 (53%) patients, while the laparoscopic approach was performed in 42 (47%) patients. Pheochromocytoma was benign in 86 patients (93%) [mean size was 4.3 cm] and the malignant form was found in five patients (7%) [mean size was 10 cm].

CONCLUSIONS

These data from a large cohort of patients are consistent with those reported in the literature and show that pheochromocytoma is an in important challenge for clinicians.

Diagnosis of silent pheochromocytoma and paraganglioma

Pheochromocytomas or functioning paragangliomas can present in a dramatic manner with headache, palpitations and sometimes shock, but many occur with few symptoms despite at times markedly elevated catecholamine levels. Hypertension is not invariable, and may be paroxysmal. Increased diligence in the diagnosis of presymptomatic pheochromocytoma/paraganglioma is warranted from autopsy studies, suggesting that many of these tumors may be fatal at first presentation. Fortunately, an increasing number of pheochromocytomas/paragangliomas are now diagnosed before the advent of symptoms, either as an incidental finding on abdominal imaging or by targeted surveillance in subjects with known genetic susceptibility. The challenges and pitfalls associated with diagnosis of these silent pheochromocytoma/paragangliomas are reviewed in this article.

Adrenal cortical carcinoma masquerading as pheochromocytoma: a case report

Adrenocortical carcinoma (ACC) is a malignant tumour arising from the adrenal cortex, while pheochromocytoma is a catecholamine secreting tumour of the adrenal medulla or extra adrenal sites. Both conditions are very rare, with incidence of approximately 1–2 cases per million adults annually. Most adrenocortical tumours are functioning. ACC can be associated with clinical Cushing syndrome and virilisation due to excessive production of cortisol and androgens, respectively. However, it is rare for ACC to present clinically as pheochromocytoma. We report a case of a 28-year-old lady who presented with paroxysmal hypertension and palpitations associated with raised urinary vanillyl mandelic acid. On examination, there was postural hypotension and ballotable mass in right lumbar region with no obvious features suggestive of Cushing syndrome or virilisation. A huge right suprarenal mass with areas of necrosis and calcification was noted on the abdomen CT. A right adrenalectomy was done. The histology was consistent with ACC. There are reported cases of ACC presenting with clinical features of pheochromocytoma but limited in number, accounting for barely a dozen cases in the literature. This pseudopheochromocytoma may be due to the presence of neuroendocrine features in ACC.

Preoperative embolization reduces the risk of cathecolamines release at the time of surgical excision of large pelvic extra-adrenal sympathetic paraganglioma

A 30-year-old woman with severe hypertension was admitted to the hospital with a history of headache, palpitations, and diaphoresis following sexual intercourse. Twenty-four hour urinary excretion of free catecholamines and metabolites was markedly increased as was serum chromogranin A. Computed tomography scan revealed a large mass in the left adnex site and magnetic resonance imaging confirmed the computer tomography finding, suggesting the presence of extra-adrenal sympathetic paraganglioma. I-metaiodobenzyl guanidine scintigram revealed an increased uptake in the same area. Transcatheter arterial embolization of the mass resulted in marked decreases in blood pressure and urinary excretion of free catecholamines and metabolites. Surgical excision of the mass was then accomplished without complication. Preoperative embolization is a useful and safe procedure which may reduce the risk of catecholamines release at the time of surgical excision in large pelvic extra-adrenal sympathetic paraganglioma.

Subclinical phaeochromocytoma

Phaeochromocytomas and paragangliomas are neural crest-derived tumours. Autopsy studies indicate that relatively large numbers of these tumours remain undiagnosed during life. This may reflect non-specific signs and symptoms and low medical alertness in evaluating the clinical picture or it may reflect a silent clinical presentation - the subclinical phaeochromocytoma. The associated clinical picture depends on the capacity of the tumours to release catecholamines and sometimes biologically active peptides. Hypertension is the hallmark of catecholamine release, but the amount, type and pattern of catecholamine secretion is extremely variable. Some tumours have low or intermittent secretory activity, some produce mainly or solely dopamine, while others very rarely do not synthesize or release any catecholamines (non-secretory or non-functional tumours). Such tumours may present with mild or even absent signs and symptoms of catecholamine excess. Low secretory activity may reflect small tumour size or differences in secretory phenotypes associated with the biochemical and genetic background of the tumours. Tumours due to succinate dehydrogenase subunit B mutations are often subclinical, poorly differentiated, contain low amounts of catecholamines, and are usually malignant at diagnosis. Adrenoceptor desensitization can result in a subclinical presentation, even when catecholamine levels are high. Subclinical phaeochromocytomas are often discovered as incidentalomas during radiological procedures or during routine screening for phaeochromocytoma in carriers of mutations in one of the ten currently identified tumour susceptibility genes. Undiagnosed phaeochromocytomas, whether or not subclinical and even if biologically benign, may cause extremely deleterious consequences or even death, following abrupt release of catecholamines.

Endomyocardial biopsy in a patient with hemorrhagic pheochromocytoma presenting as inverted Takotsubo cardiomyopathy

A 29-year-old female patient presented with shock and dyspnea due to heart failure and pulmonary edema. Echocardiography indicated excessive contraction limited to the left ventricular apex and akinesis of the basal and middle ventricle, which were confirmed by emergency left ventriculography. The finding was diagnostic of inverted Takotsubo cardiomyopathy. An abdominal computed tomography scan showed a tumor in the left adrenal gland with a central low-density area, and the plasma and urinary catecholamines were strikingly elevated. Taken together, these findings suggested the presence of a hemorrhagic pheochromocytoma. A myocardial biopsy in the very acute stage on the day of admission revealed neutrophilic infiltration and contraction-band necrosis, which was indistinguishable from the previously reported pathology in the acute phase of idiopathic Takotsubo cardiomyopathy without pheochromocytoma. The diagnosis of pheochromocytoma in this case was confirmed 7 weeks later by surgical removal of the left adrenal gland with massive hemorrhage at the center of the pheochromocytoma. The marked similarity of the endomyocardial pathology between this case and cases with idiopathic Takotsubo cardiomyopathy strongly points to catecholamine excess as a common causality for Takotsubo cardiomyopathy with or without pheochromocytoma.

Hormonal activity in clinically silent adrenal incidentalomas

INTRODUCTION

The rapid development of modern imaging techniques, has led to an increase in accidentally discovered adrenal masses without clinically apparent hormonal abnormalities. Such tumours have been termed "incidentalomas". The diagnostic work-up in patients with adrenal incidentalomas is aimed at the determination of hormonal activity of the tumour and identification of patients with potentially malignant tumours. The aim of our study was a retrospective analysis of selected clinical characteristics and hormonal studies in accidentally discovered adrenal tumours.

MATERIAL AND METHODS

Fourty hundred sixty-three patients with serendipitously discovered adrenal masses, diagnosed and treated in the Department of Endocrinology and Internal Diseases, Medical University of Gdansk as well as in the affiliated Endocrinology Clinic between 1993 and October of 2009 were included in the analysis. Out of all patients, 245 were referred for adrenalectomy.

RESULTS

We found that clinically "silent" tumours often demonstrate subclinical hormonal activity. In our report, increased 24-h urinary excretion of cortisol correlated positively with tumour size (p < 0.001). Moreover, a statistical relationship was demonstrated between tumour size and serum cortisol concentration assessed in the 1 mg dexamethasone suppression test (p < 0.001). Increased values of dehydroepiandrosterone/dehydroepiandrosterone sulphate were more often found in malignant than in benign tumours (p < 0.01). Urinary concentrations of 17-ketosteroids correlate positively with diagnosis of adrenocortical cancer (p = 0.02).

CONCLUSIONS

We found that clinically "silent" tumours often demonstrate subclinical hormonal activity (subclinical Cushing syndrome, subclinical pheochromocytoma, low-symptomatic adrenocortical cancer).

False-negative ¹²³I-MIBG SPECT is most commonly found in SDHB-related pheochromocytoma or paraganglioma with high frequency to develop metastatic disease

The purpose of this study was to present the characteristics and outcome of patients with proven pheochromocytoma or paraganglioma who had false-negative iodine-123 metaiodobenzylguanidine single photon emission computed tomography ((123)I-MIBG SPECT). Twenty-one patients with false-negative (123)I-MIBG SPECT (7 males, 14 females), aged 13-55 years (mean: 41.40 years), were included. We classified them as nonmetastatic or metastatic according to the stage of the disease at the time of false-negative (123)I-MIBG SPECT study, the location and size of the tumor, plasma and urinary catecholamine and metanephrine levels, genetic mutations, and outcome in terms of occurrence and progression of metastases and death. Thirteen patients were evaluated for metastatic tumors, while the remaining eight were seen for nonmetastatic disease. All primary tumors and multiple metastatic foci did not show avid (123)I-MIBG uptake regardless of the tumor diameter. The majority of patients had extraadrenal tumors with hypersecretion of normetanephrine or norepinephrine. SDHB mutations were present in 52% (n=11) of cases, RET mutation in 4% (n=1), and the rest were apparently sporadic. Twenty-four percent (n=5) had metastatic disease on initial presentation. Fourteen patients were followed for 3-7 years. Of them, 71% (n=10) had metastatic disease and the majority had SDHB mutations. Nine are still alive, while five (four with SDHB) died due to metastatic disease. We concluded that false-negative (123)I-MIBG SPECT is frequently related to metastatic tumors and usually due to SDHB mutations with unfavorable prognosis. We therefore recommend that patients with false-negative (123)I-MIBG SPECT be tested for SDHB mutations and undergo more regular and close follow-up.

Pheochromocytoma - update on disease management

Pheochromocytomas are rare endocrine tumors that can present insidiously and remain undiagnosed until death or onset of clear manifestations of catecholamine excess. They are often referred to as one of the 'great mimics' in medicine. These tumors can no longer be regarded as a uniform disease entity, but rather as a highly heterogeneous group of chromaffin cell neoplasms with different ages of onset, secretory profiles, locations, and potential for malignancy according to underlying genetic mutations. These aspects all have to be considered when the tumor is encountered, thereby enabling optimal management for the patient. Referral to a center of specialized expertise for the disease should be considered wherever possible. This is not only important for surgical management of patients, but also for post-surgical follow up and screening of disease in patients with a hereditary predisposition to the tumor. While preoperative management has changed little over the last 20 years, surgical procedures have evolved so that laparoscopic resection is the standard of care and partial adrenalectomy should be considered in all patients with a hereditary condition. Follow-up testing is essential and should be recommended and ensured on a yearly basis. Managing such patients must now also take into account possible underlying mutations and the appropriate selection of genes for testing according to disease presentation. Patients and family members with identified mutations then require an individualized approach to management. This includes consideration of distinct patterns of biochemical test results during screening and the appropriate choice of imaging studies for tumor localization according to the mutation and associated differences in predisposition to adrenal, extra-adrenal and metastatic disease.

Phaeochromocytoma in a 20-year-old Nigerian, resolving the dilemma of benignity or malignancy

Pheochromocytomas are rare tumors that present a diagnostic challenge in developing countries. They occur in the adrenal gland and as paragangliomas along the sympathetic chain. Clinical features are usually those of sustained or paroxysmal hypertension and complications thereof. Surgical extirpation remains the mainstay of treatment and is greatly facilitated by accurate pre-operative tumor localization. Pre-operative medical management with antihypertensive medication has led to significant reductions in peri-operative mortality. Determination of malignancy is difficult in the absence of obvious metastases. We present a case of left adrenal phechromocytoma that was stabilized. Adrenalectomy had a good outcome and the patient has so far been followed up for a year.

Risk of catecholamine crisis in patients undergoing resection of unsuspected pheochromocytoma

PURPOSE

To report the risk of catecholamine crisis in patients undergoing resection of unsuspected pheochromocytoma.

MATERIALS AND METHODS

Over a four-year period, we retrospectively identified four patients who underwent resection of adrenal pheochromocytoma in whom the diagnosis was unsuspected based on preoperative clinical, biochemical, and imaging evaluation.

RESULTS

None of the patients exhibited preoperative clinical features of catecholamine excess. Preoperative biochemical screening in two patients was normal. CT scan performed in all patients demonstrated a nonspecific enhancing adrenal mass. During surgical resection of the adrenal mass, hemodynamic instability was observed in two of four patients, and one of these two patients also suffered a myocardial infarct.

CONCLUSION

Both surgeons and radiologists should maintain a high index of suspicion for pheochromocytoma, as the tumor can be asymptomatic, biochemically negative, and have nonspecific imaging features. Resection of such unsuspected pheochromocytomas carries a substantial risk of intraoperative hemodynamic instability.

Malignant pheochromocytomas and paragangliomas: a diagnostic challenge

INTRODUCTION

Malignant pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare disorders arising from the adrenal gland, from the glomera along parasympathetic nerves or from paraganglia along the sympathetic trunk. According to the WHO classification, malignancy of PCCs and PGLs is defined by the presence of metastases at non-chromaffin sites distant from that of the primary tumor and not by local invasion. The overall prognosis of metastasized PCCs/PGLs is poor. Surgery offers currently the only change of cure. Preferably, the discrimination between malignant and benign PCCs/PGLs should be made preoperatively.

METHODS

This review summarizes our current knowledge on how benign and malignant tumors can be distinguished.

CONCLUSION

Due to the rarity of malignant PCCs/PGLs and the obvious difficulties in distinguishing benign and malignant PCCs/PGLs, any patient with a PCC/PGL should be treated in a specialized center where a multidisciplinary setting with specialized teams consisting of radiologists, endocrinologist, oncologists, pathologists and surgeons is available. This would also facilitate future studies to address the existing diagnostic and/or therapeutic obstacles.

Phaeochromocytoma: a catecholamine and oxidative stress disorder

The WHO classification of endocrine tumors defines pheochromocytoma as a tumor arising from chromaffin cells in the adrenal medulla - an intra-adrenal paraganglioma. Closely related tumors of extra-adrenal sympathetic and parasympathetic paraganglia are classified as extra-adrenal paragangliomas. Almost all pheochromocytomas and paragangliomas produce catecholamines. The concentrations of catecholamines in pheochromocytoma tissues are enormous, potentially creating a volcano that can erupt at any time. Significant eruptions result in catecholamine storms called "attacks" or "spells". Acute catecholamine crisis can strike unexpectedly, leaving traumatic memories of acute medical disaster that champions any intensive care unit. A very well-defined genotype-biochemical phenotype relationship exists, guiding proper and cost-effective genetic testing of patients with these tumors. Currently, the production of norepinephrine and epinephrine is optimally assessed by the measurement of their O-methylated metabolites, normetanephrine or metanephrine, respectively. Dopamine is a minor component, but some paragangliomas produce only this catecholamine or this together with norepinephrine. Methoxytyramine, the O-methylated metabolite of dopamine, is the best biochemical marker of these tumors. In those patients with equivocal biochemical results, a modified clonidine suppression test coupled with the measurement of plasma normetanephrine has recently been introduced. In addition to differences in catecholamine enzyme expression, the presence of either constitutive or regulated secretory pathways contributes further to the very unique mutation-dependent catecholamine production and release, resulting in various clinical presentations. Oxidative stress results from a significant imbalance between levels of prooxidants, generated during oxidative phosphorylation, and antioxidants. The gradual accumulation of prooxidants due to metabolic oxidative stress results in proto-oncogene activation, tumor suppressor gene inactivation, DNA damage, and genomic instability. Since the mitochondria serves as the main source of prooxidants, any mitochondrial impairment leads to severe oxidative stress, a major outcome of which is tumor development. In terms of cancer pathogenesis, pheochromocytomas and paragangliomas represent tumors where the oxidative phosphorylation defect due to the mutation of succinate dehydrogenase is the cause, not a consequence, of tumor development. Any succinate dehydrogenase pathogenic mutation results in the shift from oxidative phosphorylation to aerobic glycolysis in the cytoplasm (also called anaerobic glycolysis if hypoxia is the main cause of such a shift). This phenomenon, also called the Warburg effect, is well demonstrated by a positive [18F]-fluorodeoxyglycose positron emission tomography scan. Microarray studies, genome-wide association studies, proteomics and protein arrays, metabolomics, transcriptomics, and bioinformatics approaches will remain powerful tools to further uncover the pathogenesis of these tumors and their unique markers, with the ultimate goal to introduce new therapeutic options for those with metastatic or malignant pheochromocytoma and paraganglioma. Soon oxidative stress will be tightly linked to a multistep cancer process in which the mutation of various genes (perhaps in a logistic way) ultimately results in uncontrolled growth, proliferation, and metastatic potential of practically any cell. Targeting the mTORC, IGF-1, HIF and other pathways, topoisomerases, protein degradation by proteosomes, balancing the activity of protein kinases and phosphatases or even synchronizing the cell cycle before any exposure to any kind of therapy will soon become a reality. Facing such a reality today will favor our chances to "beat" this disease tomorrow.

Functional vagal paraganglioma: a case report illustrating diagnosis and management

We report a case of functional vagal paraganglioma to illustrate the biochemical and radiological imaging tests important in diagnosis and to highlight the importance of a multidisciplinary team approach to manage the preoperative, perioperative, and postoperative effects of catecholamine secretion from these tumors.

Catecholamine-secreting paragangliomas: recent progress in diagnosis and perioperative management

Catecholamine-secreting paragangliomas (CSPs) present challenges for the managing team of surgeons and anesthesiologists. Without proper preoperative management and planning, the patient is at high risk for complications and significant morbidity. A review of the literature looking at all aspects of the care of patients with CSP was performed to provide a consensus on the comprehensive care of these difficult patients. A case study is also provided to illustrate the management algorithm. Specific recommendations are made with regards to preoperative workup, including serum and urine testing, tumor localization, angiography, and embolization. Preoperative and intraoperative management techniques by the surgical and anesthesiology teams are discussed, including pharmaceutical interventions and fluid management. Aspects of postoperative care are also discussed. Management of patients with CSP requires significant attention to detail by a multidisciplinary team of surgeons and anesthesiologists. By following the recommendations included within this article, the morbidity associated with removal of these tumors can be significantly reduced or eliminated.

Hypertension in pheochromocytoma: characteristics and treatment

Pheochromocytoma is a tumor of the chromaffin cells in the adrenal medulla and sympathetic paraganglia, which synthesizes and secretes catecholamines. Norepinephrine, epinephrine, and dopamine all act on their target receptors, which causes a physiologic change in the body. High circulating levels of catecholamines can lead to severe hypertension and can have devastating effects on multiple body systems (eg, cardiovascular, cerebrovascular), and can lead to death if untreated. Although surgical treatment represents the only modality of ultimate cure, pharmacologic preoperative treatment remains the mainstay of successful outcome.

Role of (18)F-FDG PET/CT, (123)I-MIBG SPECT, and CT in Restaging Patients Affected by Malignant Pheochromocytoma

PURPOSE

Pheochromocytoma (PH) is a rare catecholamine-secreting tumor that arises from chromaffin tissue within the adrenal medulla and extra-adrenal sites; commonly it is sporadic, and malignant PH accounts for about 10% of all cases. Several imaging modalities have been used for the diagnosis and staging of this tumor: functional imaging using radio-labelled metaiodobenzylguanidine and, more recently, (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET/CT), which offers substantial sensitivity and specificity to correctly detect metastatic PH and helps to identify patients suitable for treatment with radiopharmaceuticals. The aim of our study was to compare CT, (18)F-FDG PET/CT, and (123)I-metaiodobenzylguanidine single photon emission tomography ((123)I-MIBG SPECT) as feasible methods to restage patients diagnosed histologically with PH.

METHODS

We retrospectively evaluated 38 patients (27 females and 11 males; mean age: 44 ± 15 years) with malignant PH documented histologically after surgical intervention. These patients underwent CT, (18)F-FDG PET/CT, and (123)I-MIBG SPECT.

RESULTS

(18)F-FDG PET/CT showed positive results for neoplastic tissue in 33/38 patients (86.8%) and negative in 5/38 (13.2%), in concordance with CT alone. (123)I-MIBG SPECT was positive in 30/38 patients (78,9%) and negative in 8/38 (21.1%). No differences in lesion numbers were found between (18)F-FDG PET/CT and CT, whereas a difference could be demonstrated between (18)F-FDG PET/CT and (123)I-MIBG SPECT.

CONCLUSION

(18)F-FDG PET/CT could more accurately restage patients with PH than CT and (123)I-MIBG SPECT, also in the absence of a staging study.

Predictive characteristics of malignant pheochromocytoma

Purpose

The prognosis of patients with malignant pheochromocytoma is poor, but the predictive factors are not well understood. We aimed to identify the clinical characteristics predictive of malignancy after initial surgical removal in patients with pheochromocytoma.

Materials and Methods

We retrospectively reviewed the records of 152 patients diagnosed with pheochromocytoma, including 5 (3.3%) with metastasis at the time of the initial surgical excision and 12 (7.9%) who developed metastasis during follow-up. To determine the factors predictive of malignancy, we compared clinical, radiographical, and urinary chemical findings between patients with benign and malignant disease. Mean follow-up was 41.5 months (range, 0.9-298 months) after surgery.

Results

Malignant tumors were significantly larger than benign tumors (11.1±4.0 cm vs. 6.2±3.4 cm, p<0.001), and postoperative persistence of arterial hypertension was more frequent after removal of malignant than benign tumors (p=0.001). Among the 147 patients without metastatic disease at diagnosis, those who developed metastasis had significantly lower concentrations of urinary catecholamine metabolites per unit of tumor, including vanillylmandelic acid (1.2 vs. 3.7 mg/day/cm, p=0.049), epinephrine (4.5 vs. 168.9 µg/day/cm, p=0.008), and norepinephrine (13.1 vs. 121.8 mg/day/cm, p<0.001). The overall 5-year metastasis-free survival rate was 84.4% and was significantly higher in patients with smaller tumors (≤5.5 vs. >5.5 cm; 90.6% vs. 81.2%, p=0.025) and higher 24-hour secretion of vanillylmandelic acid (>2.1 vs. ≤2.1 mg/day/cm; 94.9% vs. 70.9%, p=0.019).

Conclusions

Large tumor size (>5.5 cm) and minimally elevated 24-hour urinary vanillylmandelic acid (≤2.1 mg/day/cm) were significantly associated with a higher probability of a malignant pheochromocytoma portending a lower metastasis-free survival and mandating more rigorous follow-up after surgery.

An evaluation of the Danish national clinical guidelines for von Hippel-Lindau (VHL)

PURPOSE

Von Hippel-Lindau (VHL) is a rare hereditary and potentially fatal cancer syndrome. Because of its unpredictable manifestations in various organ systems, surveillance is not linked to a single department and may therefore be incomplete. Denmark published national guidelines for the surveillance of patients with manifest and possible VHL in 2005 and was one of the first countries to do so. The present study is the first of its kind; patients with suspected and manifest VHL were followed at a single institution according to the national guidelines. The purpose was to evaluate (1) to what extent the guidelines were being followed and (2) what findings were disclosed.

METHODS

The study included 27 individuals with diagnosed (14 patients) or suspected (13 patients) VHL, observing the Danish VHL guidelines at the Department of Neurosurgery, Rigshospitalet, Denmark, from October 2002 to April 2008. The data were collected by reviewing patient records.

RESULTS

Manifestations that influenced the treatment were revealed in 48% of the patients, and 26% of the patients demonstrated asymptomatic manifestations. All investigations were conducted at a lower frequency than recommended. Individuals diagnosed with VHL were subjected to more clinical testing than individuals with suspected VHL.

CONCLUSIONS

This study shows that the national clinical guidelines were not being fully complied with. The investigations revealing the most serious VHL manifestations were those carried out with a frequency closest to the recommendations. Many investigations led to clinical consequences. Therefore, we recommend that all patients with suspected or manifest VHL are monitored according to structured clinical guidelines.

Integrative epigenomic and genomic analysis of malignant pheochromocytoma

Epigenomic and genomic changes affect gene expression and contribute to tumor development. The histone modifications trimethylated histone H3 lysine 4 (H3K4me3) and lysine 27 (H3K27me3) are epigenetic regulators associated to active and silenced genes, respectively and alterations of these modifications have been observed in cancer. Furthermore, genomic aberrations such as DNA copy number changes are common events in tumors. Pheochromocytoma is a rare endocrine tumor of the adrenal gland that mostly occurs sporadic with unknown epigenetic/genetic cause. The majority of cases are benign. Here we aimed to combine the genome-wide profiling of H3K4me3 and H3K27me3, obtained by the ChIP-chip methodology, and DNA copy number data with global gene expression examination in a malignant pheochromocytoma sample. The integrated analysis of the tumor expression levels, in relation to normal adrenal medulla, indicated that either histone modifications or chromosomal alterations, or both, have great impact on the expression of a substantial fraction of the genes in the investigated sample. Candidate tumor suppressor genes identified with decreased expression, a H3K27me3 mark and/or in regions of deletion were for instance TGIF1, DSC3, TNFRSF10B, RASSF2, HOXA9, PTPRE and CDH11. More genes were found with increased expression, a H3K4me3 mark, and/or in regions of gain. Potential oncogenes detected among those were GNAS, INSM1, DOK5, ETV1, RET, NTRK1, IGF2, and the H3K27 trimethylase gene EZH2. Our approach to associate histone methylations and DNA copy number changes to gene expression revealed apparent impact on global gene transcription, and enabled the identification of candidate tumor genes for further exploration.

Phaeochromocytomas and functional paragangliomas: clinical management

Phaeochromocytomas (PH) and functional paragangliomas (FPGL) are neoplasms of adrenal (PH) or extra-adrenal (FPGL) chromaffin tissue that synthesize catecholamines. Catecholamines are converted into inactive metabolites, metanephrines, within the tumour and the diagnosis of PH/FPGL is therefore based on the quantification of plasma or urinary metanephrines. The tumour can be located by computed tomography, magnetic resonance imaging and metaiodobenzylguanidine scintigraphy. Patients are treated by tumour resection following alpha-blockade. PH and FPGL may be sporadic or part of several genetic diseases. Patients with PH/FPGL should be followed up indefinitely as the disease may recur, particularly if they have inherited or extra-adrenal tumours. About 10% of tumours are malignant either at initial surgery or during follow-up. Recurrences and malignancy are more frequent in cases with large or extra-adrenal tumours, and in SDHB mutation carriers. Treatments for progressive malignant PH/FPGL include tumour debulking, metabolic radiotherapy, chemotherapy, and possibly tyrosine kinase inhibitors.

Hereditäre Paragangliome

Hereditäre Paragangliome/Phäochromozytome werden autosomal-dominant vererbt. Es lassen sich 3 Formen, PGL1, PGL3 und PGL4 unterscheiden. Sie werden verursacht durch Mutationen in den Genen SDHD, SDHC und SDHB, welche für Komponenten des Komplexes II der mitochondrialen Atmungskette (Succinat-Ubiquinon-Reduktase, SDH) kodieren. Bei allen 3 Formen findet sich „loss of heterozygosity“ (LOH) der Region des mutierten Gens in Tumor-DNA. Dies führt zu Funktionsverlust der SDH, Anhäufung von Succinat sowie Sauerstoffradikalen. Dadurch werden hypoxieabhängige Stoffwechselwege aktiviert, welche zur Tumorbildung führen könnten. Während PGL3 und PGL4 sowohl durch maternal als auch durch paternal vererbte Keimbahnmutationen der Gene SDHC bzw. SDHB verursacht werden, findet sich PGL1 fast ausschließlich bei paternaler Transmission des mutierten SDHD-Gens. Diese Beobachtung lässt sich erklären durch partielle Inaktivierung (Imprinting) des maternalen SDHD-Gens und Induktion hypoxieabhängiger Gene in Paragangliengewebe, wodurch der Verlust des gesamten maternalen Chromosoms 11 durch Non-Disjunction begünstigt werden könnte.

Fever with Multiple Organ Failure: Not Always Sepsis

We present the case of a 52-year-old female admitted with fever and multiple organ failure, initially treated for presumed sepsis. However, the combination of multiple organ failure, hyperthermia and vascular instability raised the suspicion of a phaeochromocytoma multisystem crisis. An emergency abdominal ultrasound in the intensive care unit disclosed a large tumour of the right adrenal. Despite specific medical treatment for the presumed adrenal emergency and multiple organ failure, the patient succumbed. Postmortem examination verified the diagnosis of phaeochromocytoma.

Clinically silent chromaffin-cell tumors: Tumor characteristics and long-term prognosis in patients with incidentally discovered pheochromocytomas

BACKGROUND

Chromaffin-cell tumors (CCT), a rare group of catecholamine producing endocrine neoplasms, are traditionally suspected and diagnosed in patients presenting with episodic hypertension, together with the classic triad of headache, sweating, and tachycardia. Asymptomatic CCT are increasingly diagnosed, frequently as "incidentalomas". We have conducted a multicenter retrospective study, to assess the characteristics of a group of patients with clinically silent CCT, compared with a group of patients with typical CCT.

METHODS

Forty-three consecutive patients with CCT (24 with silent and 19 with typical tumors) have been retrospectively studied for a period of up to 20 yr (between 1989 and 2009); clinical picture, biochemical tests, as well as topographic and functional assessment were analyzed at diagnosis and periodically following treatment. Surgical samples were reviewed for neuroendocrine markers and for signs of invasiveness.

RESULTS

Patients with clinically silent CCT were significantly older than the typical ones (56.3±3.4 vs 48.0±4.8 yr; p<0.05); 15 of them (63%) were completely asymptomatic, and 9 patients (37%) complained of non-specific abdominal symptoms. Hypertension was present in only 6 silent CCT patients (25%), it was well controlled [mean blood pressure (BP) 134/84 mmHg], and persisted after surgery in only 2 patients. Fourteen out of twenty-four silent CCT patients (58%) were managed pre-operatively with prophylactic combination of α and β blockade, despite normal BP values. Clinically silent CCT were larger than typical CCT (mean diameter of 5.2±2.3 cm vs 4.6±1.5 cm, p<0.05) and secreted higher a mounts of normeta neph rines. All clinically silent CCT patients were defined as "cured" after surgery.

CONCLUSION

Clinically silent CCT are more prevalent than previously reported. With an adequate pre-surgical diagnosis and patient preparation, the prognosis of silent tumors is usually excellent.