Diagnosing phaeochromocytoma/paraganglioma in a patient presenting with critical illness: biochemistry versus imaging

Evaluation and management of hypertensive emergency

Hypertensive emergencies cause substantial morbidity and mortality, particularly when acute organ injury is present. Careful and effective strategies to reduce blood pressure and diminish the effects of pressure-mediated injury are essential. While the selection of specific antihypertensive medications varies little across different forms of hypertensive emergencies, the intensity of blood pressure reduction to the target pressure differs substantially. Treatment hinges on balancing the positive effects of lowering blood pressure with the potential for negative effects of organ hypoperfusion in patients with altered autoregulatory mechanisms. When patients do not have acute organ injury in addition to severe hypertension, they benefit from a conservative, outpatient approach to blood pressure management. In all cases, long term control of blood pressure is paramount to prevent recurrent hypertensive emergencies and improve overall prognosis. This review discusses the current evidence and guidelines on the evaluation and management of hypertensive emergency.

Phaeochromocytoma and paraganglioma

Phaeochromocytomas and paragangliomas are rare catecholamine-producing neuroendocrine tumours which can potentially cause catastrophic crises with high morbidity and mortality. This best practice article considers the causes and presentation of such tumours, screening and diagnostic tests, management of these patients and consideration of family members at risk.

Pheochromocytoma. Preoperative approach

Pheochromocytomas are rare neuroendocrine tumors that derive from the chromaffin cells of the adrenal medulla and secrete catecholamines. The measurement of plasma or fractionated urine metanephrines is the hormonal determination of choice for the biochemical diagnosis. Once the biochemical diagnosis is confirmed, the next step is the localization study. It is recommended to request a genetic study in all patients with pheochromocytomas since 40% of cases are hereditary. Once the diagnostic study is completed, preoperative treatment with alpha blockers should be instituted at least 7-14 days before adrenalectomy. However, in low-risk patients, the omission of presurgical treatment could be considered if the surgery is performed in centers with experience and a strict monitoring of the patient is carried out during the perioperative period. This document offers a practical guide on the diagnosis and perioperative approach in patients with pheochromocytomas.

Catecholamine-induced hypertensive crises: current insights and management

Phaeochromocytomas and paragangliomas (PPGLs) release catecholamines leading to catecholamine-induced hypertensive (CIH) crises, with blood pressure greater than or equal to 180/120 mm Hg. CIH crises can be complicated by tachyarrhythmias, hypotension, or life-threatening target organ damage while treatment remains undefined, often requiring co-management between endocrinologists and cardiologists. Furthermore, biochemical diagnosis of a PPGL as a cause of a CIH crisis can be difficult to identify or confounded by comorbid conditions, potentially resulting in misdiagnosis. Here, we combine relevant evidence, 60 years of collective clinical experience, insights derived from assessing over 2600 patients with PPGL, and supplementary outcomes from 100 patients (treated at the National Institutes of Health) with a CIH crisis to inform diagnosis and treatment of CIH crises. Recognising that disparities exist between availability, cost, and familiarity of various agents, flexible approaches are delineated allowing for customisation, given institutional availability and provider preference. A CIH crisis and its complications are readily treatable with available drugs, with effective intervention defining an avenue for mitigating consequent morbidity and mortality in patients with PPGL.

Pheochromocytoma: a changing perspective and current concepts

This article aims to review current concepts in diagnosing and managing pheochromocytoma and paraganglioma (PPGL). Personalized genetic testing is vital, as 40-60% of tumors are linked to a known mutation. Tumor DNA should be sampled first. Next-generation sequencing is the best and most cost-effective choice and also helps with the expansion of current knowledge. Recent advancements have also led to the increased incorporation of regulatory RNA, metabolome markers, and the NETest in PPGL workup. PPGL presentation is highly volatile and nonspecific due to its multifactorial etiology. Symptoms mainly derive from catecholamine (CMN) excess or mass effect, primarily affecting the cardiovascular system. However, paroxysmal nature, hypertension, and the classic triad are no longer perceived as telltale signs. Identifying high-risk subjects and diagnosing patients at the correct time by using appropriate personalized methods are essential. Free plasma/urine catecholamine metabolites must be first-line examinations using liquid chromatography with tandem mass spectrometry as the gold standard analytical method. Reference intervals should be personalized according to demographics and comorbidity. The same applies to result interpretation. Threefold increase from the upper limit is highly suggestive of PPGL. Computed tomography (CT) is preferred for pheochromocytoma due to better cost-effectiveness and spatial resolution. Unenhanced attenuation of >10HU in non-contrast CT is indicative. The choice of extra-adrenal tumor imaging is based on location. Functional imaging with positron emission tomography/computed tomography and radionuclide administration improves diagnostic accuracy, especially in extra-adrenal/malignant or familial cases. Surgery is the mainstay treatment when feasible. Preoperative α-adrenergic blockade reduces surgical morbidity. Aggressive metastatic PPGL benefits from systemic chemotherapy, while milder cases can be managed with radionuclides. Short-term postoperative follow-up evaluates the adequacy of resection. Long-term follow-up assesses the risk of recurrence or metastasis. Asymptomatic carriers and their families can benefit from surveillance, with intervals depending on the specific gene mutation. Trials primarily focusing on targeted therapy and radionuclides are currently active. A multidisciplinary approach, correct timing, and personalization are key for successful PPGL management.

Biochemical Assessment of Pheochromocytoma and Paraganglioma

Pheochromocytoma and paraganglioma (PPGL) require prompt consideration and efficient diagnosis and treatment to minimize associated morbidity and mortality. Once considered, appropriate biochemical testing is key to diagnosis. Advances in understanding catecholamine metabolism have clarified why measurements of the O-methylated catecholamine metabolites rather than the catecholamines themselves are important for effective diagnosis. These metabolites, normetanephrine and metanephrine, produced respectively from norepinephrine and epinephrine, can be measured in plasma or urine, with choice according to available methods or presentation of patients. For patients with signs and symptoms of catecholamine excess, either test will invariably establish the diagnosis, whereas the plasma test provides higher sensitivity than urinary metanephrines for patients screened due to an incidentaloma or genetic predisposition, particularly for small tumors or in patients with an asymptomatic presentation. Additional measurements of plasma methoxytyramine can be important for some tumors, such as paragangliomas, and for surveillance of patients at risk of metastatic disease. Avoidance of false-positive test results is best achieved by plasma measurements with appropriate reference intervals and preanalytical precautions, including sampling blood in the fully supine position. Follow-up of positive results, including optimization of preanalytics for repeat tests or whether to proceed directly to anatomic imaging or confirmatory clonidine tests, depends on the test results, which can also suggest likely size, adrenal vs extra-adrenal location, underlying biology, or even metastatic involvement of a suspected tumor. Modern biochemical testing now makes diagnosis of PPGL relatively simple. Integration of artificial intelligence into the process should make it possible to fine-tune these advances.

Pheochromocytoma-induced cardiogenic shock: A multicentre analysis of clinical profiles, management and outcomes

OBJECTIVE

There is still uncertainty about the management of patients with pheochromocytoma-induced cardiogenic shock (PICS). This study aims to investigate the clinical presentation, management, and outcome of patients with PICS.

METHODS

We collected, retrospectively, the data of 18 patients without previously known pheochromocytoma admitted to 8 European hospitals with a diagnosis of PICS.

RESULTS

Among the 18 patients with a median age of 50 years (Q1-Q3: 40-61), 50% were men. The main clinical features at presentation were pulmonary congestion (83%) and cyclic fluctuation of hypertension peaks and hypotension (72%). Echocardiography showed a median left ventricular ejection fraction (LVEF) of 25% (Q1-Q3: 15-33.5) with an atypical- Takotsubo (TTS) pattern in 50%. Inotropes/vasopressors were started in all patients and temporary mechanical circulatory support (t-MCS) was required in 11 (61%) patients. All patients underwent surgical removal of the pheochromocytoma; 4 patients (22%) were operated on while under t-MCS. The median LVEF was estimated at 55% at discharge. Only one patient required heart transplantation (5.5%), and all patients were alive at a median follow-up of 679 days.

CONCLUSIONS

PICS should be suspected in case of a CS with severe cyclic blood pressure fluctuation and rapid hemodynamic deterioration, associated with increased inflammatory markers or in case of TTS progressing to CS, particularly if an atypical TTS echocardiographic pattern is revealed. T-MCS should be considered in the most severe cases. The main challenge is to stabilize the patient, with medical therapy or with t-MCS, since it remains a reversible cause of CS with a low mortality rate.

The clinical utility of plasma and urine metanephrines in hypertensive emergency

INTRODUCTION

Metanephrines (MTNs) are metabolites of catecholamines and are constantly produced in high amounts by pheochromocytomas and paragangliomas (PPGLs). Marked MTN elevations (> 3 times the upper limit of normal [ULN]) are highly suggestive of PPGL. The frequency of marked MTN elevations in non-PPGL hypertensive emergencies (HTNEs) is unknown.

METHODS

We retrospectively analyzed plasma free metanephrine (PMTN) and 24-h urinary fractionated metanephrine (UMTN) levels in 48 consecutive patients (59.7 ± 15.6 years; 48% female; BMI: 31 ± 9.7 kg/m²) hospitalized for HTNE, defined as systolic blood pressure (SBP) > 180 mmHg or diastolic blood pressure (DBP) > 120 mmHg with end-organ damage. PMTNs were measured in 47 patients, UMTNs were measured in 16 patients, and both PMTNs and UMTNs were measured in 15 patients.

RESULTS

PMTN/UMTN levels were not associated with SBP/DBP, comorbidities, end-organ damage, or interfering medications, the exception being that plasma normetanephrines (PNMNs) were significantly associated with comorbidities (Adj. R² = 0.16; p = 0.04) and interfering medications (Adj. R² = 0.15; p = 0.03), although with weak correlation. Marked MTN (specifically PNMN) elevations (647, 521, and 453 pg/mL; normal ≤ 148 pg/mL) were noted in only three patients (6%).

DISCUSSION

Marked MTN elevations in HTNE are uncommon. Therefore, we recommend against measuring MTN in the setting of an apparent precipitating cause of HTNE to avoid unnecessary testing and imaging. Testing for MTN in HTNE should be pursued only when there is no clear precipitating cause and in cases where there is strong underlying clinical suspicion for PPGL. However, should testing be performed, marked MTN elevations should not be disregarded as being a commonly occurring result of HTNE.

Preanalytical Considerations and Outpatient Versus Inpatient Tests of Plasma Metanephrines to Diagnose Pheochromocytoma

CONTEXT

Sampling of blood in the supine position for diagnosis of pheochromocytoma and paraganglioma (PPGL) results in lower rates of false positives for plasma normetanephrine than seated sampling. It is unclear how inpatient vs outpatient testing and other preanalytical factors impact false positives.

OBJECTIVE

We aimed to identify preanalytical precautions to minimize false-positive results for plasma metanephrines.

METHODS

Impacts of different blood sampling conditions on plasma metanephrines were evaluated, including outpatient vs inpatient testing, sampling of blood in semi- vs fully recumbent positions, use of cannulae vs direct venipuncture, and differences in outside temperature. A total of 3147 patients at 10 tertiary referral centers were tested for PPGL, including 278 with and 2869 without tumors. Rates of false-positive results were analyzed.

RESULTS

Outpatient rather than inpatient sampling resulted in 44% higher plasma concentrations and a 3.4-fold increase in false-positive results for normetanephrine. Low temperature, a semi-recumbent position, and direct venipuncture also resulted in significantly higher plasma concentrations and rates of false-positive results for plasma normetanephrine than alternative sampling conditions, although with less impact than outpatient sampling. Higher concentrations and rates of false-positive results for plasma normetanephrine with low compared with warm temperatures were only apparent for outpatient sampling. Preanalytical factors were without impact on plasma metanephrines in patients with PPGL.

CONCLUSION

Although inpatient blood sampling is largely impractical for screening patients with suspected PPGL, other preanalytical precautions (eg, cannulae, warm testing conditions) may be useful. Inpatient sampling may be reserved for follow-up of patients with difficult to distinguish true- from false-positive results.

Inpatient Measurements of Urine Metanephrines are Indistinguishable from Pheochromocytoma: Retrospective Cohort Study

BACKGROUND

Pheochromocytoma is a rare cause of acute cardiovascular disease; however, any severe illness may have high catecholamines, simulating pheochromocytoma. We determined the spectrum of urine metanephrines from inpatient and outpatient collections without pheochromocytoma, compared with confirmed pheochromocytoma patients.

METHODS

Retrospective analysis using centralized laboratory data serving all outpatients and hospitals in southern Alberta. The analysis comprised 24-hour urine normetanephrine and metanephrine (UNM-UMN) results collected from hospital inpatients, community outpatients, and patients from a comprehensive provincial pheochromocytoma registry.

RESULTS

There were 974 unique inpatients (including 132 from intensive care), 6802 outpatients, and 58 pheochromocytoma patients. Among outpatient, general ward, and intensive care unit (ICU) patients, 18.7%, 34.4%, and 67.4% of results, respectively, were supranormal. Although pheochromocytoma patients had higher median UNM-UMN vs inpatients, there was substantial overlap. Receiver operating characteristic (ROC) analysis showed area under the curve (AUC) of 0.64-0.91 to detect true pheochromocytoma (P < .0001), with progressively poorer discrimination among hospitalized and ICU-dependent patients. A 24-hour urine normetanephrine >6.95 nmol/d had 98% specificity for pheochromocytoma when inpatient general ward samples were included, but only 46% sensitivity and 13% positive predictive value for pheochromocytoma. Considering ICU collections, 98% specificity required results more than fivefold above the upper reference limit and still had poor positive predictive value. A model combining both UNM and UMN results as a cross-product marginally improved the ROC AUC, but improved sensitivity in outpatients and ward patients but not ICU patients.

CONCLUSION

There is a high degree of overlap in UNM-UMN between hospitalized patients and pheochromocytoma; high test specificity is not achieved in this population unless >3-5 times the upper reference limit.

Properly Collected Plasma Metanephrines Excludes PPGL After False-Positive Screening Tests

CONTEXT

False-positive results are common for pheochromocytoma/paraganglioma (PPGL) real-world screening.

OBJECTIVE

Determine the correlation between screening urine and seated plasma metanephrines in outpatients where PPGL was absent, compared to meticulously prepared and supine-collected plasma metanephrines with age-adjusted references.

DESIGN

Retrospective cohort study.

SETTING

Databases from a single-provider provincial laboratory (2012-2018), a validated PPGL registry, and a manual chart review from a specialized endocrine testing unit.

PATIENTS

PPGL registry data excluded known PPGL cases from the laboratory database. Outpatients having both urine and plasma metanephrines <90 days apart.

METHODS

The correlation between urine and seated plasma measures along with the total positivity rate. All cases of plasma metanephrines drawn in the endocrine unit were reviewed for test indication and test positivity rate.

RESULTS

There were 810 non-PPGL pairs of urine and plasma metanephrines in the laboratory database; 46.1% of urine metanephrines were reported high. Of seated outpatient plasma metanephrines drawn a median of 5.9 days later, 19.2% were also high (r = 0.33 and 0.50 for normetanephrine and metanephrine, respectively). In contrast, the meticulously prepared and supine collected patients (n = 139, 51% prior high urine metanephrines) had <3% rate of abnormal high results in patients without known PPGL/adrenal mass.

CONCLUSIONS

There was a poor-to-moderate correlation between urine and seated plasma metanephrines. Up to 20% of those with high urine measures also had high seated plasma metanephrines in the absence of PPGL. Properly prepared and collected supine plasma metanephrines had a false-positive rate of <3% in the absence of known PPGL/adrenal mass.

Catecholamine physiology and its implications in patients with COVID-19

The risk factors for severe COVID-19 are diverse, yet closely resemble the clinical manifestations of catecholamine excess states (eg, hypertension, cardiovascular disease, immune dysregulation, and hyperglycaemia), suggesting a potentially common basis for disease. Unfortunately, severe illness (eg, respiratory failure, compromised cardiac function, and shock) incurred by COVID-19 hinders the direct study of catecholamines in these patients, especially among those on multiple medications or those on adrenaline or noradrenaline infusions, or both. Phaeochromocytoma and paraganglioma (PPGL) are tumours that secrete catecholamines, namely adrenaline and noradrenaline, often in excess. PPGL are well studied disease processes in which the effects of catecholamines are easily discernible and therefore their potential biochemical and physiological influences in patients with COVID-19 can be explored. Because catecholamines are expected to have a role in patients with critical illness, patients on vasopressor infusions, and patients who sustain some acute and chronic physical stresses, the challenges involved in the management of catecholamine excess states are directly relevant to the treatment of patients with COVID-19. In this Personal View, we discuss the complex interplay between catecholamines and COVID-19, and the management of catecholamine excess states, while referencing relevant insights derived from the study of PPGL.

Genetics, diagnosis, management and future directions of research of phaeochromocytoma and paraganglioma: a position statement and consensus of the Working Group on Endocrine Hypertension of the European Society of Hypertension

: Phaeochromocytoma and paraganglioma (PPGL) are chromaffin cell tumours that require timely diagnosis because of their potentially serious cardiovascular and sometimes life- threatening sequelae. Tremendous progress in biochemical testing, imaging, genetics and pathophysiological understanding of the tumours has far-reaching implications for physicians dealing with hypertension and more importantly affected patients. Because hypertension is a classical clinical clue for PPGL, physicians involved in hypertension care are those who are often the first to consider this diagnosis. However, there have been profound changes in how PPGLs are discovered; this is often now based on incidental findings of adrenal or other masses during imaging and increasingly during surveillance based on rapidly emerging new hereditary causes of PPGL. We therefore address the relevant genetic causes of PPGLs and outline how genetic testing can be incorporated within clinical care. In addition to conventional imaging (computed tomography, MRI), new functional imaging approaches are evaluated. The novel knowledge of genotype-phenotype relationships, linking distinct genetic causes of disease to clinical behaviour and biochemical phenotype, provides the rationale for patient-tailored strategies for diagnosis, follow-up and surveillance. Most appropriate preoperative evaluation and preparation of patients are reviewed, as is minimally invasive surgery. Finally, we discuss risk factors for developing metastatic disease and how they may facilitate personalised follow-up. Experts from the European Society of Hypertension have prepared this position document that summarizes the current knowledge in epidemiology, genetics, diagnosis, treatment and surveillance of PPGL.

Acute Stress Cardiomyopathy: Heart of pheochromocytoma

Stress cardiomyopathy (SCM) is a syndrome characterized by transient regional systolic dysfunction of the left ventricle in the absence of angiographic evidence of coronaropathy. This abnormality is associated with high levels of catecholamines. Stress cardiomyopathy is also called Takotsubo (TS) cardiomyopathy. Pheochromocytoma crisis can occur spontaneously or can be precipitated by manipulation of the tumor, trauma, certain medications or stress for example during non-adrenal surgery. The main drugs leading to pheochromocytoma crisis include D2 dopamine receptor antagonists, noncardioselective β-adrenergic receptor blockers, tricyclic antidepressants and related neurotransmitter uptake blockers, sympathomimetics, certain peptide and steroid hormones and several agents used during induction of anesthesia. Patients can develop symptoms of heart failure associated with tachyarrhythmia, cardiogenic shock with hypotension and collapse, or apparent acute coronary syndromes. This review describes pathophysiology, epidemiology, diagnosis criteria and management of SCM.

Microangiopathic Hemolytic Anemia and Fulminant Renal Failure: A Rare Manifestation of Pheochromocytoma

Pheochromocytoma is a rare adrenal tumor that is classically associated with the triad of paroxysmal tachycardia, diaphoresis, and headaches. However, it can have myriad manifestations. We present a case of a 31-year-old male who presented with abdominal pain, hypertensive emergency, and renal failure. Abdominal imaging demonstrated a left adrenal mass. Plasma metanephrines (153 pg/ml, n < 57) and normetanephrines (1197 pg/ml, n < 148) were noted to be elevated, leading to the diagnosis of pheochromocytoma. Intravenous antihypertensives were utilized to control his blood pressure. Hemodialysis was initiated given the degree of renal dysfunction. The patient subsequently developed hemolytic anemia, requiring the transfusion of multiple units of packed red cells. He developed acute respiratory failure leading to intubation, but was thereafter liberated from the ventilator following clinical stabilization. Uncontrolled hypertension precipitated by pheochromocytoma can cause microangiopathic hemolytic anemia and renal insufficiency. This case is notable not only for the occurrence of this rare presentation, but also for the severity of manifestations in a young male with no known significant comorbidities.

Cardiovascular Manifestations of Pheochromocytoma

Pheochromocytomas are rare endocrine tumors that can have a significant impact on a variety of organ systems, including the cardiovascular system. Although the pathophysiology is not completely understood, pheochromocytomas exert their effects through high levels of catecholamines, mainly epinephrine and norepinephrine, which stimulate adrenergic receptors, including those within the cardiovascular system. Although the most common cardiovascular manifestation is hypertension, patients with pheochromocytoma can present with arrhythmia, hypotension, shock, myocardial ischemia, cardiomyopathy, aortic dissection, and peripheral ischemia. The medical management of the cardiovascular effects of pheochromocytoma is via blockade of adrenergic receptors, usually through the use of alpha blockers, with the addition of beta blockers if needed. However, only surgical resection of the pheochromocytoma is potentially curative, and this tumor requires unique management perioperatively. Because of the variability of presentation and the significant morbidity and mortality of patients with an undiagnosed pheochromocytoma, this entity should not be overlooked in the evaluation of patients with a wide variety of cardiovascular disorders.

Extracorporeal membrane oxygenation in pheochromocytoma-induced cardiogenic shock

Extracorporeal membrane oxygenation has been extensively used for cardiopulmonary support in cardiogenic shock. However, its clinical value in the management of pheochromocytoma crisis remains unclear. We report a rare case of life-threatening cardiogenic shock managed with peripheral venoarterial extracorporeal membrane oxygenation combined with endovascular left ventricular venting, in a 40-year-old female patient, in the setting of unknown adrenal pheochromocytoma. We highlight the life-saving role of extracorporeal membrane oxygenation in undiagnosed endocrine emergencies, allowing cardiac and end-organ recovery, and giving time for accurate diagnosis and specific treatment in such unusual situations.

Pheochromocytoma Crisis in the ICU: A French Multicenter Cohort Study With Emphasis on Rescue Extracorporeal Membrane Oxygenation

OBJECTIVES

To describe the characteristics, management, and outcome of patients admitted to ICUs for pheochromocytoma crisis.

DESIGN

A 16-year multicenter retrospective study.

SETTING

Fifteen university and nonuniversity ICUs in France.

PATIENTS

Patients admitted in ICU for pheochromocytoma crisis.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

We included 34 patients with a median age of 46 years (40-54 yr); 65% were males. At admission, the median Sequential Organ Failure Assessment score was 8 (4-12) and median Simplified Acute Physiology Score II 49.5 (27-70). The left ventricular ejection fraction was consistently decreased with a median value of 30% (15-40%). Mechanical ventilation was required in 23 patients, mainly because of congestive heart failure. Vasoactive drugs were used in 23 patients (68%) and renal replacement therapy in eight patients (24%). Extracorporeal membrane oxygenation was used as a rescue therapy in 14 patients (41%). Pheochromocytoma was diagnosed by CT in 33 of 34 patients. When assayed, urinary metanephrine and catecholamine levels were consistently elevated. Five patients underwent urgent surgery, including two during extracorporeal membrane oxygenation. Overall ICU mortality was 24% (8/34), and overall 90-day mortality was 27% (9/34). Crude 90-day mortality was not significantly different between patients managed with versus without extracorporeal membrane oxygenation (22% vs 30%) (p = 0.7) despite higher severity scores at admission in the extracorporeal membrane oxygenation group.

CONCLUSIONS

Mortality is high in pheochromocytoma crisis. Routinely considering this diagnosis and performing abdominal CT in patients with unexplained cardiogenic shock may allow an earlier diagnosis. Extracorporeal membrane oxygenation and adrenalectomy should be considered as a therapeutic in most severe cases.

Update on Modern Management of Pheochromocytoma and Paraganglioma

Despite all technical progress in modern diagnostic methods and treatment modalities of pheochromocytoma/paraganglioma, early consideration of the presence of these tumors remains the pivotal link towards the best possible outcome for patients. A timely diagnosis and proper treatment can prevent the wide variety of potentially catastrophic cardiovascular complications. Modern biochemical testing should include tests that offer the best available diagnostic performance, measurements of metanephrines and 3-methoxytyramine in plasma or urine. To minimize false-positive test results particular attention should be paid to pre-analytical sampling conditions. In addition to anatomical imaging by computed tomography (CT) or magnetic resonance imaging, new promising functional imaging modalities of photon emission tomography/CT using with somatostatin analogues such as ⁶⁸Ga-DOTATATE (⁶⁸Ga-labeled DOTA(0)-Tyr(3)-octreotide) will probably replace ¹²³I-MIBG (iodine-123-metaiodobenzylguanidine) in the near future. As nearly half of all pheochromocytoma patients harbor a mutation in one of the 14 tumor susceptibility genes, genetic testing and counseling should at least be considered in all patients with a proven tumor. Post-surgical annual follow-up of patients by measurements of plasma or urinary metanephrines should last for at least 10 years for timely detection of recurrent or metastatic disease. Patients with a high risk for recurrence or metastatic disease (paraganglioma, young age, multiple or large tumors, genetic background) should be followed up lifelong.

Extracorporeal membrane oxygenation for pheochromocytoma-induced cardiogenic shock

BACKGROUND

Pheochromocytoma, a rare catecholamine-producing tumor, might provoke stress-induced Takotsubo-like cardiomyopathy and severe cardiogenic shock. Because venoarterial-extracorporeal membrane oxygenation (VA-ECMO) rescue of pheochromocytoma-induced refractory cardiogenic shock has rarely been reported, we reviewed our ICU patients' presentations and outcomes.

METHODS

All pheochromocytoma-induced refractory cardiogenic shock cases managed with VA-ECMO (January 2007-March 2015) were prospectively included and reviewed. We also performed a systematic review on this topic.

RESULTS

Nine patients (7 women, 2 men; 31-51 [median, 43 (IQR 36-49) years old]) were included; none had a previously known pheochromocytoma. Six of them had medical histories suggestive of the diagnosis: palpitations and headaches for several months for four, multiple endocrine neoplasia syndrome type 1 for one and recurrent Takotsubo disease for one; at hospital admission, all were hypertensive despite cardiogenic shock. Three others had an identified surgical triggering factor. All nine patients rapidly developed refractory cardiogenic shock with very severe left ventricular (LV) impairment (LV ejection-fraction range 5-20%; LV outflow-tract velocity-time integral range 3-8 cm). Seven patients' abdominal computed tomography scans showed pheochromocytoma-suggestive adrenal gland tumors (no scan during ICU stay for 2). Despite VA-ECMO implantation, three patients died of refractory multiple organ failure. For the six others, myocardial function improved and ECMO was removed 3-7 days post-implantation; α- and β-blockers were progressively introduced. Five survivors underwent pheochromocytoma excision 3 weeks-4 months post-ICU discharge, with satisfactory outcomes. One patient, whose pheochromocytoma was diagnosed 1 year after the index event, underwent uneventful surgical adrenalectomy. Systematic review retrieved 40 cases of pheochromocytoma-induced cardiogenic shock requiring mechanical support (mostly ECMO), with a mortality rate of 7%. Pheochromocytoma was removed surgically after mechanical support weaning in 31 patients and during mechanical support in 5. Four were not operated.

CONCLUSIONS

Pheochromocytoma is a rare but reversible cause of cardiogenic shock amenable to VA-ECMO rescue. Adrenal gland imaging should be obtained for all patients with unexplained cardiogenic shock. Lastly, it might be safer to perform adrenalectomy several weeks after the initial catastrophic presentation, once recovery of LV systolic function is complete.

Interest of systematic screening of pheochromocytoma in patients with neurofibromatosis type 1

OBJECTIVE

Pheochromocytoma (PHEO) may occur in 0.1-5.7% of patients presenting with a neurofibromatosis type 1 (NF1). Current recommendations are to explore only symptomatic patients. The objective of the study is to evaluate the prevalence and the interest of a systematic PHEO screening in this population.

DESIGN

A prospective study in a French tertiary center including consecutive NF1 patients older than 18 years.

METHODS

A systematic screening combining abdominal imaging and urinary fractionated metanephrines was proposed. In case of positivity of one or both exams, (123)I-metaiodobenzylguanidine scintigraphy or [(18)F]-fluoro-dihydroxyphenylalanine PET imaging was performed. The diagnosis of secreting PHEO was retained in case of elevated urinary metanephrines associated with positive scintigraphy and non-secreting PHEO when urinary metanephrines were normal with a positive scintigraphy.

RESULTS

Between January 2014 and August 2015, 234 patients were included and 156 patients (66.7%) completed both exams. In these 156 patients, 12 PHEOs were diagnosed, representing a prevalence of 7.7%. Of these, six PHEOs were secreting, with only two symptomatic patients. The tumor size of these PHEOs were bigger than that of non-secreting PHEO (25.2 ± 6.6 vs 14 ± 6.9 mm, P = 0.0165). One lesion was bilateral. Mean metanephrine and normetanephrine levels were 3.2 ± 2.6N and 2.8 ± 1N respectively. Three patients underwent surgery. The six patients with non-secreting PHEO were asymptomatic. One of them had bilateral lesion and one underwent surgery.

CONCLUSIONS

PHEO in NF1, whether or not secreting, are mostly asymptomatic. The current strategy to explore only symptomatic patients leads to an underestimation of prevalence with the risks inherent to the existence of an unrecognized PHEO.

15 YEARS OF PARAGANGLIOMA: Clinical manifestations of paraganglioma syndromes types 1-5

The paraganglioma (PGL) syndromes types 1-5 are autosomal dominant disorders characterized by familial predisposition to PGLs, phaeochromocytomas (PCs), renal cell cancers, gastrointestinal stromal tumours and, rarely, pituitary adenomas. Each syndrome is associated with mutation in a gene encoding a particular subunit (or assembly factor) of succinate dehydrogenase (SDHx). The clinical manifestations of these syndromes are protean: patients may present with features of catecholamine excess (including the classic triad of headache, sweating and palpitations), or with symptoms from local tumour mass, or increasingly as an incidental finding on imaging performed for some other purpose. As genetic testing for these syndromes becomes more widespread, presymptomatic diagnosis is also possible, although penetrance of disease in these syndromes is highly variable and tumour development does not clearly follow a predetermined pattern. PGL1 syndrome (SDHD) and PGL2 syndrome (SDHAF2) are notable for high frequency of multifocal tumour development and for parent-of-origin inheritance: disease is almost only ever manifest in subjects inheriting the defective allele from their father. PGL4 syndrome (SDHB) is notable for an increased risk of malignant PGL or PC. PGL3 syndrome (SDHC) and PGL5 syndrome (SDHA) are less common and appear to be associated with lower penetrance of tumour development. Although these syndromes are all associated with SDH deficiency, few genotype-phenotype relationships have yet been established, and indeed it is remarkable that such divergent phenotypes can arise from disruption of a common molecular pathway. This article reviews the clinical presentations of these syndromes, including their component tumours and underlying genetic basis.