Pheochromocytoma and paraganglioma: diagnosis, genetics, management, and treatment

Tumor progression in tympanojugular paragangliomas: the role of radiotherapy and wait and scan

INTRODUCTION

Tympanojugular paragangliomas (TJ PGLs) are rare tumors characterized by bone infiltration and erosion and a close relationship with critical structures, such as cranial nerves and internal carotid artery. For these reasons, their management represents a tough challenge. Since the fifties, radio-therapy (RT) has been proposed as an alternative treatment aimed at avoiding tumor progression. However, the indolent nature of the tumor, characterized by slow growth, is a crucial factor that needs to be considered before offering radiation.

METHODS

This study aims to examine tumor progression in RT patients through a systematic review of the literature and in TJ PGL patients who underwent solely wait and scan at our department.

RESULTS

The rate of tumor progression in the RT group was 8.9%, while in the wait and scan cohort was 12.9%. This data suggests the innate slow growth of PGLs. However, it is not possible to draw certain conclusions because of the wide heterogeneity of the studies.

CONCLUSION

When complete surgical excision of TJ PGLs is not feasible, appropriate counseling and patient selection, including comprehensive tumor classification, should be performed before proposing RT to control tumor progression, since wait and scan may represent a reasonable option in selected cases.

Peptide receptor radionuclide therapy with 177Lu- or 90Y-SSTR peptides in malignant pheochromocytomas (PCCs) and paragangliomas (PGLs): results from a single institutional retrospective analysis

BACKGROUND

Malignant pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare tumors and available systemic therapies are limited.

AIM

To explore the role of peptide receptor radionuclide therapy (PRRT) with Yttrium-90 (90Y) and Lutetium-177 (177Lu) peptides in pheochromocytomas (PCCs) and paragangliomas (PGLs).

METHODS

We retrospectively analyzed more than 1500 patients with histologically proven neuroendocrine tumors treated with 177Lu- or 90Y-DOTA-TATE or -TOC between 1999 to 2017 at our Institute. Overall, 30 patients with confirmed malignant PCCs and PGLs matched inclusion/exclusion criteria and were considered eligible for this analysis.

RESULTS

Thirty (n = 30) patients were treated: 22 with PGLs and 8 with PCCs (12 M and 18 F, median age 47 [IQR: 35-60 years]). Eighteen patients (n = 18) had head and neck PGLs, 3 patients thoracic PGLs and 1 patient abdominal PGL. Sixteen patients (53%) had locally advanced and fourteen (47%) had metastatic disease. Twenty-seven (90%) patients had disease progression at baseline. Four (13%) patients were treated with 90Y, sixteen (53%) with 177Lu and ten (33%) with 90Y + 177Lu respectively. The median total cumulative activity from treatment with 90Y- alone was 9.45 GBq (range 5.11-14.02 GBq), from 177Lu- alone was 21.9 GBq (7.55-32.12 GBq) and from the combination treatment was 4.94 GBq from 90Y- and 6.83 GBq from 177Lu- (ranges 1.04-10.1 and 2.66-20.13 GBq, respectively). Seven out of 30 (23%) patients had partial response and 19 (63%) stable disease. Median follow up was 8.9 years (IQR: 2.9-12). The 5-y and 10-y PFS was 68% (95% CI: 48-82) and 53% (95% CI: 33-69), respectively, whereas 5-y and 10-y OS was 75% (95% CI: 54-87) and 59% (95% CI: 38-75), respectively. Grade 3 or 4 acute hematological toxicity occurred in three patients, two with leucopenia and one with thrombocytopenia, respectively.

CONCLUSION

PRRT with 177Lu- or 90Y-DOTA-TATE or -TOC is feasible and well tolerated in advanced PGLs and PCCs.

Clinical diagnosis of pheochromocytoma and paraganglioma-induced secondary hypertension through UPLC-MS/MS analysis of plasma catecholamines and their metabolites

This study aimed to elucidate the clinical diagnostic value of plasma catecholamines and their metabolites for pheochromocytoma and paraganglioma (PPGL)-induced secondary hypertension using ultraperformance liquid chromatography-mass spectrometry (UPLC-MS/MS). The study population included 155 patients with PPGL that were divided into the PPGL with hypertension (n = 79) and a PPGL without hypertension (n = 76) groups, and 90 healthy volunteers and 90 patients with primary hypertension as the control groups. UPLC-MS/MS was performed to detect plasma levels of catecholamines and their metabolites, including dopamine, vanillylmandelic acid (VMA), norepinephrine, metanephrine, and normetanephrine. Receiver operating characteristic curves were generated to analyze the diagnostic value of the plasma levels of catecholamines and their metabolites in PPGL-induced secondary hypertension. Patients in the primary hypertension and PPGL without hypertension groups had higher levels of dopamine, VMA, norepinephrine, metanephrine, and normetanephrine than patients in the normal group (all p < .05). On the other hand, patients in the PPGL with hypertension group had higher levels of dopamine, VMA, norepinephrine, metanephrine, and normetanephrine than patients in the normal, primary hypertension, and PPGL without hypertension groups (all p < .05). Collectively, our findings showed that dopamine, VMA, norepinephrine, metanephrine, and normetanephrine are all effective biomarkers for the diagnosis of PPGL and PPGL-induced secondary hypertension.

A case report on pheochromocytoma mimicking as fulminant myocarditis-a diagnostic challenge

We present an exceptional case of a 53-year-old female, initially misdiagnosed with fulminant myocarditis, but later correctly diagnosed with pheochromocytoma. The presentation of the patient included a spectrum of symptoms such as headache, chest discomfort, palpitations, and dyspnea, following the intake of Domperidone. Two weeks prior to admission, the patient had experienced episodes of diarrhea and a low-grade fever. Unresolved symptoms and an unmanageable surge in blood pressure despite comprehensive fulminant myocarditis treatment prompted further investigation. The discovery of an adrenal mass via a CT scan and subsequent biochemical tests led to the confirmation of pheochromocytoma. Implementation of alpha-blockade therapy and a successful laparoscopic adrenalectomy resulted in significant clinical improvement. This case underscores the diagnostic intricacies of pheochromocytoma and highlights the need for vigilance when faced with severe, unresponsive cardiovascular symptoms.

The Role of Catecholamines in the Pathogenesis of Diseases and the Modified Electrodes for Electrochemical Detection of Catecholamines: A Review

Catecholamines (CAs), which include adrenaline, noradrenaline, and dopamine, are neurotransmitters and hormones that critically regulate the cardiovascular system, metabolism, and stress response in the human body. The abnormal levels of these molecules can lead to the development of various diseases, including pheochromocytoma and paragangliomas, Alzheimer's disease, and Takotsubo cardiomyopathy. Due to their low cost, high sensitivity, flexible detection strategies, ease of integration, and miniaturization, electrochemical techniques have been extensively employed in the detection of CAs, surpassing traditional analytical methods. Electrochemical detection of CAs in real samples is challenging due to the tendency of poisoning electrode. Chemically modified electrodes have been widely used to solve the problems of poor sensitivity and selectivity faced by bare electrodes. There are a few articles that provide an overview of electrochemical detection and efficient enrichment of CAs, but there is a dearth of updates on the role of CAs in the pathogenesis of diseases. Additionally, there is still a lack of systematic synthesis with a focus on modified electrodes for electrochemical detection. Thus, this review provides a summary of the recent clinical pathogenesis of CAs and the modified electrodes for electrochemical detection of CAs published between 2017 and 2022. Moreover, challenges and future perspectives are also highlighted. This work is expected to provide useful guidance to researchers entering this interdisciplinary field, promoting further development of CAs pathogenesis, and developing more novel chemically modified electrodes for the detection of CAs.

Mastering bladder paraganglioma for optimal treatment: a case report of robot-assisted surgery

Bladder paraganglioma is a rare neuroendocrine neoplasm, either functional or non-functional, arising from the urinary bladder. Functional variants present with catecholamine-related symptoms, while non-functional variants pose diagnostic challenges, mimicking urothelial carcinoma. Misdiagnosis risks underscore the importance of accurate identification for appropriate patient management. In this case, a 52-year-old man, diagnosed incidentally with hypertension and reported occasional post-micturition tachycardia, underwent abdominal ultrasound for known hepatic cyst follow-up, revealing an oval hypoechoic bladder mass. Initial consideration of bladder urothelial carcinoma prompted further investigation with contrast-enhanced CT scan and cystoscopy that confirmed extrinsic mass nature, and subsequent robotic-assisted partial cystectomy was performed. Histologically, the removed mass exhibited characteristic features of bladder paraganglioma. Postoperative recovery was uneventful, with resolution of post-micturition tachycardia at 1 month. Follow-up includes endocrinological evaluation and a 6-month CT scan. In conclusion, bladder paraganglioma should be considered in para-vesical mass differentials. This case highlights the importance of meticulous history collection, even in asymptomatic patients, the need for a multidisciplinary approach for accurate diagnosis and management of this rare condition, and the robotic approach as a viable option.

Development and internal validation of a novel predictive model for SDHB mutations in pheochromocytomas and retroperitoneal paragangliomas

Aim

To develop and internally validate a novel predictive model for SDHB mutations in pheochromocytomas and retroperitoneal paragangliomas (PPGLs).

Methods

Clinical data of patients with PPGLs who presented to Peking Union Medical College Hospital from 2013 to 2022 and underwent genetic testing were retrospectively collected. Variables were screened by backward stepwise and clinical significance and were used to construct multivariable logistic models in 50 newly generated datasets after the multiple imputation. Bootstrapping was used for internal validation. A corresponding nomogram was generated based on the model. Sensitivity analyses were also performed.

Results

A total of 556 patients with PPGLs were included, of which 99 had a germline SDHB mutation. The prediction model revealed that younger age of onset [Odds ratio (OR): 0.93, 95% CI: 0.91-0.95], synchronous metastasis (OR: 6.43, 95% CI: 2.62-15.80), multiple lesion (OR: 0.22, 95% CI: 0.09-0.54), retroperitoneal origin (OR: 5.72, 95% CI: 3.13-10.47), negative 131I-meta-iodobenzylguanidine (MIBG) (OR: 0.34, 95% CI: 0.15-0.73), positive octreotide scintigraphy (OR: 3.24, 95% CI: 1.25-8.43), elevated 24h urinary dopamine (DA) (OR: 1.72, 95% CI: 0.93-3.17), NE secretory type (OR: 2.83, 95% CI: 1.22- 6.59), normal secretory function (OR: 3.04, 95% CI: 1.04-8.85) and larger tumor size (OR: 1.09, 95% CI: 0.99-1.20) were predictors of SDHB mutations in PPGLs, and showed good and stable predictive performance with a mean area under the ROC curve (AUC) of 0.865 and coefficient of variation of 2.2%.

Conclusions

This study provided a novel and useful tool for predicting SDHB mutations by integrating easily obtained clinical data. It may help clinicians select suitable genetic testing methods and make appropriate clinical decisions for these high-risk patients.

Interleukin-6-producing paraganglioma as a rare cause of systemic inflammatory response syndrome: a case report

Pheochromocytomas and paragangliomas (PPGLs) may secrete hormones or bioactive neuropeptides such as interleukin-6 (IL-6), which can mask the clinical manifestations of catecholamine hypersecretion. We report the case of a patient with delayed diagnosis of paraganglioma due to the development of IL-6-mediated systemic inflammatory response syndrome (SIRS). A 58-year-old woman presented with dyspnea and flank pain accompanied by SIRS and acute cardiac, kidney, and liver injuries. A left paravertebral mass was incidentally observed on abdominal computed tomography (CT). Biochemical tests revealed increased 24-hour urinary metanephrine (2.12 mg/day), plasma norepinephrine (1,588 pg/mL), plasma normetanephrine (2.27 nmol/L), and IL-6 (16.5 pg/mL) levels. 18F-fluorodeoxyglucose (FDG) positron emission tomography/CT showed increased uptake of FDG in the left paravertebral mass without metastases. The patient was finally diagnosed with functional paraganglioma crisis. The precipitating factor was unclear, but phendimetrazine tartrate, a norepinephrine-dopamine release drug that the patient regularly took, might have stimulated the paraganglioma. The patient's body temperature and blood pressure were well controlled after alpha-blocker administration, and the retroperitoneal mass was surgically resected successfully. After surgery, the patient's inflammatory, cardiac, renal, and hepatic biomarkers and catecholamine levels improved. In conclusion, our report emphasizes the importance of IL-6-producing PPGLs in the differential diagnosis of SIRS.

Intraoperative difficulty in cardiorespiratory management during anesthesia for retroperitoneal paraganglioma resection

We report the anesthetic management of a case of paraganglioma, which was challenging because of intraoperative circulatory changes and difficult ventilatory management. A 52-year-old man with a history of chronic obstructive pulmonary disease was scheduled for paraganglioma resection under general anesthesia combined with epidural anesthesia. Since a marked increase in blood pressure was observed immediately after administration of rocuronium, antihypertensive agents were administered as necessary. The ventilatory settings were initially adjusted to deliver a tidal volume of 7 mL/kg, and the drive pressure was maintained at 13 cm H₂O or less. However, despite increasing the minute volume, PETCO₂ increased to 60 mmHg and PaCO₂ to 76 mmHg before tumor removal. Blood pressure decreased immediately after tumor removal, and PETCO₂ and PaCO₂ gradually returned to normal. We speculated that the increases in PETCO₂ and PaCO₂ might have been due to both an increase in endogenous catecholamine secretion as well as chronic obstructive pulmonary disease. It is important to preoperatively evaluate the functionality of the tumor and to anticipate perioperative cardiorespiratory instability in the management of paragangliomas.

Multimodality Imaging Appearance of Intrapericardial Paragangliomas

Paragangliomas are neuroendocrine tumors of the sympathetic and parasympathetic nervous system that originate from neural crest cells. Less than 1% of paragangliomas are found in the heart, originating from intrinsic cardiac ganglia cells in the posterior wall the atria, atrioventricular groove, and along the root of the great vessels. A 10-year review of our institution's database identified nine patients who had documented intrapericardial paragangliomas. We describe the multimodality imaging appearance of these tumors. The most common findings include embedment and wrapping around the great vessels and atrioventricular groove within the confines of the pericardium, markedly avid heterogeneous enhancement, distinct engorged neovascularization, and in large lesions, central low attenuation areas compatible with hemorrhage, necrosis, or cystic degeneration.

Primary intra-abdominal paraganglioma: A case report

BACKGROUND

Paragangliomas are rare neuroendocrine tumors. We hereby report a case of a localized paraganglioma found in the abdominal cavity, and review the relevant literature to improve the understanding of this disease.

CASE SUMMARY

A 29-year-old Chinese female patient was referred to our hospital due to an abdominal mass found on physical examination. Imaging revealed a mass in the left upper abdomen, suggestive of either a benign stromal tumor or an ectopic accessory spleen. Laparoscopic radical resection was subsequently performed, and histopathological analysis confirmed the diagnosis of a paraganglioma. The patient was followed up 3 months post-operation, and reported good recovery with no metastasis.

CONCLUSION

Radical resection can effectively treat intra-abdominal paragangliomas, with few side effects and low recurrence risk. In addition, early and accurate diagnosis and timely intervention are essential for the prognosis of this disease.

A Case of Retroperitoneal Paraganglioma Presenting As Dizziness and Chest Pain With a Coexisting Contralateral Primary Renal Tumor

Paraganglioma is a rare type of neuroendocrine tumor with variable clinical presentations, making diagnosis relatively challenging. In this report, we present a case of retroperitoneal paraganglioma in a patient who experienced intermittent episodes of dizziness and chest pain. Imaging studies conducted during the patient's hospitalization revealed the presence of a lesion in the upper region of the right kidney, as well as a mass in the left retroperitoneal area that was suspected to be a paraganglioma. Biochemical studies were collected, including 24-hour urine metanephrines, urine catecholamines, urine cortisol, plasma metanephrines, renin, and aldosterone. However, it took an extended period of time for these results to come back. Given high clinical suspicion, alpha-blockade was initiated without a definite diagnosis of paraganglioma. Ultimately, the patient underwent tumor resection and the final pathology confirmed paraganglioma. The pathology of the contralateral renal mass showed oncocytoma. This case serves as an illustration of the difficulties that can arise when diagnosing and treating undiagnosed paragangliomas within a community healthcare setting.

New advances in endocrine hypertension: from genes to biomarkers

Hypertension (HT) is a major cardiovascular risk factor that affects 10% to 40% of the general population in an age-dependent manner. Detection of secondary forms of HT is particularly important because it allows the targeted management of the underlying disease. Among hypertensive patients, the prevalence of endocrine HT reaches up to 10%. Adrenal diseases are the most frequent cause of endocrine HT and are associated with excess production of mineralocorticoids (mainly primary aldosteronism), glucocorticoids (Cushing syndrome), and catecholamines (pheochromocytoma). In addition, a few rare diseases directly affecting the action of mineralocorticoids and glucocorticoids in the kidney also lead to endocrine HT. Over the past years, genomic and genetic studies have allowed improving our knowledge on the molecular mechanisms of endocrine HT. Those discoveries have opened new opportunities to transfer knowledge to clinical practice for better diagnosis and specific treatment of affected subjects. In this review, we describe the physiology of adrenal hormone biosynthesis and action, the clinical and biochemical characteristics of different forms of endocrine HT, and their underlying genetic defects. We discuss the impact of these discoveries on diagnosis and management of patients, as well as new perspectives related to the use of new biomarkers for improved patient care.

Multimodality imaging appearance of intrapericardial paragangliomas

Paragangliomas are neuroendocrine tumours of the sympathetic and parasympathetic nervous systems originating from neural crest cells. Less than 1% of paragangliomas in the heart originate from intrinsic cardiac ganglia cells in the posterior wall of the atria, atrioventricular groove, and along the root of the great vessels. We describe the tumour characteristics, patient demographics, presentation, means of diagnosis, pathology correlation, management, and outcome in 11 patients with intrapericardial paragangliomas. To the authors' knowledge, this is the largest case series reported, with emphasis on multimodality imaging findings.

Minimally invasive management for multifocal pelvic retroperitoneal malignant paraganglioma: a neuropelveological approach

Background

Pheochromocytoma and Paraganglioma (PGL) are rare neuroendocrine tumors, with an estimated incidence of about 0.6 cases per 100.000 person/year. Overall, 3–8% of them are malignant. These tumors are characterized by a classic triad of symptoms (headaches, palpitations, profuse sweating) due to hypersecretion of catecholamines. Despite several advantages of minimally invasive surgery (MIS) for PGL debulking, the surgical approach is not standardized yet. In this scenario, we aimed to report a case of a multiple recurrent PGL with metastatic retroperitoneal localization involving the pelvic sidewall, excised with MIS.

Case presentation

We performed complete laparoscopic-assisted neuronavigation (LANN technique) with isolation of the sacral routes and the sciatic nerve to obtain complete exposure of the main anatomic landmarks. Robotic surgery was used to perform neurolysis of sacral plexus, and partial resection of left splanchnic nerves was needed. After the resection of the first mass, extensive neurolysis of all sacral routes, obturator nerve, pudendal nerve till the entrance of the pudendal (Alcock) canal, and sciatic nerve was performed. Finally, the mass was identified after trans gluteal incision and dissection of the maximum gluteal muscle, and a partial resection of the superior gluteal nerve and slicing of the sciatic nerve were needed to obtain a radical excision of the mass. Then neurorrhaphy of the sectioned nerve fibers of the superior gluteal nerve was performed, and nerve protection was obtained using a collagen nerve wrap. After 18 months of follow-up, the patient is free of disease at the MRI imaging and 123I-metaiodobenzylguanidine scintigraphy.

Conclusions

Minimally invasive gynecological surgery with neuropelveological approach could be considered as a feasible option in case of multifocal pelvic retroperitoneal malignant paraganglioma of the pelvic side wall.

Efficacy and safety of 225Ac-DOTATATE targeted alpha therapy in metastatic paragangliomas: a pilot study

PURPOSE

In this study, we aim to evaluate the efficacy and safety of 225AC-DOTATATE targeted alpha therapy in advanced-stage paragangliomas (PGLs).

METHODS

Nine (6 males and 3 females) consecutive patients with histologically proven PGLs were treated with 225Ac-DOTATATE targeted alpha therapy (TAT) and concomitant radiosensitizer, capecitabine, at 8-weekly intervals up to a cumulative activity of ~ 74 MBq. The primary endpoint included evaluating therapy response and disease control rate (DCR) using the RECIST 1.1 criteria. Additional secondary endpoints comprised clinical response assessment using EORTC QLQ-H&N35 questionnaire, Karnofsky Performance Scale (KPS), Eastern Cooperative Oncology Group performance status (ECOG), analgesic score (AS), dose alterations of anti-hypertensive drugs (anti-HTN), and the safety and side-effect profile evaluation as per CTCAE criteria version 5.0.

RESULTS

Following 225Ac-DOTATATE treatment, morphological response revealed partial response in 50%, stable disease in 37.5%, and disease progression in 12.5%, with a DCR of 87.5%. Similarly, the symptomatic response was remarkable, and anti-HTN drugs were stopped in 25% and reduced in 37.5%. Another significant finding in our study revealed a morphologic DCR of 66.6% (2/3) in patients who failed previous lutetium-177 peptide receptor radionuclide therapy (177Lu-PRRT). Regarding the KPS, ECOG, and AS performance scores, a notable improvement was observed post-225Ac-DOTATATE treatment. The QLQ-H&N35 symptom scores evaluated in seven H&N PGL patients showed significant improvement in all aspects. No improvement in sexual function was noted (P = 0.3559). Despite the significant reduction in the analgesic score post-treatment (P = 0.0031), the QLQ-H&N35 revealed only marginal significance concerning the intake of pain killers (P = 0.1723). No grade III/IV hematological, renal, and hepatological toxicities were noted.

CONCLUSION

The evidence from this study suggests 225Ac-DOTATATE therapy is effective and safe in the treatment of advanced-stage PGLs and also reports a clear benefit even in patient's refractory to the previous 177Lu-PRRT.

Adrenal pheochromocytoma as a rare cause of reversible left ventricular systolic dysfunction and malignant arrhythmias: a case series

Background

Pheochromocytoma is a neuroendocrine tumour originating from the chromaffin cells of adrenal glands or sympathetic paraganglia. It produces most frequently norepinephrine, epinephrine, and dopamine. As a result of non-specific and variable clinical presentation, pheochromocytoma is difficult to diagnose.

Case summary

A 37-year-old female without medical history and 57-year-old male patient with diabetes, arterial hypertension, and aortic valve replacement with a mechanical prosthesis were admitted to the hospital after successful cardiopulmonary resuscitation due to ventricular fibrillation. In both patients, coronary angiography demonstrated a normal finding, and echocardiography showed left ventricular (LV) contractile dysfunction with improvement in the subsequent examination. In the first patient, the diagnosis of stress-induced cardiomyopathy was considered as the most probable cause. She was later admitted to hospital due to acute pulmonary oedema with hypertensive crisis. Echocardiography documented reversible LV systolic dysfunction with improvement after 3 days. The course of hospitalization of the male was complicated by multi-organ dysfunction syndrome comprising renal failure, paralytic ileus, and pancreatic irritation, which normalized after 2 weeks. The diagnosis of pheochromocytoma was confirmed by laboratory tests and imaging methods. After pharmacological pre-treatment with doxazosin in both patients and bisoprolol in the female, successful adrenalectomies were performed with no relapse of tumour.

Discussion

We describe an atypical clinical presentation of pheochromocytoma with initial cardiac arrest due to ventricular fibrillation and reversible LV systolic dysfunction. Our cases underline that clinical suspicion of pheochromocytoma as a potentially correctable cause should be raised in unexplained cases of severe heart failure, ventricular arrhythmias, and cardiac arrest.

Biochemically normal adrenal pheochromocytoma following extensive central necrosis in a child with von Hippel-Lindau (VHL) gene mutation

Pheochromocytomas are rare in children. The diagnosis is usually established from a raised urinary or plasma catecholamine or their metabolites. We present a girl aged 11 years who manifested with a hypertensive crisis secondary to an adrenal tumour but with unexpectedly normal urinary metanephrine and catecholamine results. She improved spontaneously following the crisis and underwent surgery later. The histopathological study confirmed a pheochromocytoma with large central necrosis. Her genetic screening reported a pathogenic von Hippel-Lindau gene mutation. Surveillance scan postsurgery detected no other tumours. Following the catecholamine crisis, an acute infarct occurred, resulting in extensive tumour necrosis and subsequent rapid remission of symptoms and paradoxically normal biochemical markers. Although not unheard of in adults, we believe this is the first reported case of an extensive spontaneous necrosis resulting in a biochemically normal pheochromocytoma in a child.

Cross-Talk Between Nitrosative Stress, Inflammation and Hypoxia-Inducible Factor in Patients with Adrenal Masses

Background

Adrenal masses are the most common of all human tumors. The role of nitrosative stress and inflammation in cancer development has already been demonstrated. However, it is not known whether they are involved in the pathogenesis of adrenal tumors. The aim of the study was to investigate a cross-talk between nitrosative stress, inflammation and hypoxia-inducible factor (HIF-1α) in 75 patients with different types of adrenal masses (non-functional incidentaloma, pheochromocytoma and Cushing's/Conn's adenoma).

Methods

The plasma concentrations of total nitric oxide (NO), S-nitrosothiols, peroxynitrite nitrotyrosine and the activity of serum myeloperoxidase (MPO) were measured spectrophotometrically, whereas concentrations of interleukin 1 beta (IL-1β), tumor necrosis factor α (TNF-α) and hypoxia-inducible factor 1 alpha (HIF-1α) were measured using commercial ELISA kits. The control group consisted of 50 healthy people matched by age and sex to the study group. The number of subjects was determined a priori based on our previous experiment (power of the test = 0.9; α = 0.05).

Results

We found significantly higher nitrosative stress (↑nitric oxide, ↑peroxynitrite, ↑S-nitrosothiols and ↑nitrotyrosine) in the plasma of patients with adrenal tumors, which was accompanied by increased inflammatory (↑myeloperoxidase, ↑interleukin 1 beta and ↑tumor necrosis factor α) and hypoxia (HIF-1α) biomarkers. Peroxynitrite and nitrotyrosine were positively correlated with aldosterone level. Nitrosative stress was also associated with inflammation and HIF-1α. Interestingly, plasma nitrotyrosine and serum MPO differentiated patients with adrenal tumor from healthy individuals with high sensitivity and specificity. Moreover, using multivariate regression analysis, we showed that ONOO^- and IL-1β depended on cortisol level, while ONOO^-, nitrotyrosine and HIF-1α were associated with aldosterone. Unfortunately, none of the assessed biomarkers differentiated between tumor types studied, suggesting that the severity of nitrosative damage and inflammation are similar in patients with incidentaloma, pheochromocytoma, and Cushing's or Conn's adenoma.

Conclusion

Adrenal tumors are associated with increased protein nitration/S-nitrosylation and inflammation.

Targeting the Redox Balance Pathway Using Ascorbic Acid in sdhb Zebrafish Mutant Larvae

Simple Summary

Thus far, no curative therapies are available for malignant SDHB-associated phaeochromocytomas and paragangliomas (PPGLs). Therapy development is severely hampered by the limited availability of suitable animal models. In this study, we investigated the potential of the sdhb^rmc200 zebrafish model to study SDHB-associated PPGLs using a drug screening approach. One of the key features of cancer initiation and progression is redox imbalance. First, we identified increased reactive oxygen species levels in homozygous sdhb^rmc200 larvae at baseline. Next, we tested the effect of anti- and pro-oxidant ascorbic acid (Vitamin C) on these larvae. We validated the sdhb^rmc200 zebrafish model as a powerful drug screening tool to provide valuable insights into pathomechanisms, which may lead to novel therapeutic targets and therapy development in the future.

Abstract

Patients with mutations in the β-subunit of the succinate dehydrogenase (SDHB) have the highest risk to develop incurable malignant phaeochromocytomas and paragangliomas (PPGLs). Therapy development is hindered by limited possibilities to test new therapeutic strategies in vivo. One possible molecular mechanism of SDHB-associated tumorigenesis originates in an overproduction of reactive oxygen species (ROS) due to mitochondrial dysfunction. Ascorbic acid (Vitamin C) has already been shown to act as anti-cancer agent in several clinical trials for various types of cancer. In this study, the potential of the sdhb^rmc200 zebrafish model to study SDHB-associated PPGLs using a drug screening approach was investigated. First, we identified increased basal ROS levels in homozygous sdhb larvae compared to heterozygous and wild-type siblings. Using a semi high-throughput drug screening, the effectiveness of different dosages of anti- and pro-oxidant Vitamin C were assessed to evaluate differences in survival, ROS levels, and locomotor activity. Low-dosage levels of Vitamin C induced a decrease of ROS levels but no significant effects on lifespan. In contrast, high-dosage levels of Vitamin C shortened the lifespan of the homozygous sdhb^rmc200 larvae while not affecting the lifespan of heterozygous and wild-type siblings. These results validated the sdhb^rmc200 zebrafish model as a powerful drug screening tool that may be used to identify novel therapeutic targets for SDHB-associated PPGLs.

Concurrent Urinary Bladder Paraganglioma and Adrenal Phaeochromocytoma With Succinate Dehydrogenase-B Mutation

Phaeochromocytoma (PHEO) is a neoplasm that arises from chromaffin cells present in the adrenal medulla. The counterpart of the PHEO extra-adrenal is termed paraganglioma (PGL). The urinary bladder PGL is a rare tumour, and it accounts for less than 0.06% of all bladder tumours. In this report, we discuss a case of a young female who presented with symptoms of headache, dizziness, palpitations, and high blood pressure. After workup, she was diagnosed with concurrent urinary bladder PGL and adrenal PHEO, and the genetic study of the whole exon sequence indicated the presence of succinate dehydrogenase-B (SDHB) mutation. Both tumours were treated surgically; however, the patient ultimately developed recurrence, rapid progression, and metastasis. All secondary modalities were unsuccessful, and the patient was referred for palliative treatment and eventually lost to follow-up.

PGL should be included in the differential diagnosis of bladder tumours, and testing for SDHB gene mutations should be considered in all urinary PGLs. Therefore, these patients need follow-up and genetic counselling.

Adrenal pheochromocytoma: is it all or the tip of the iceberg?

Adrenal pheochromocytoma is not always a simple retroperitoneal tumor but may be part of a more complicated condition. It often has a spectrum of complex and variable imaging features, may present as a collision tumor and composite tumor, and is associated with a variety of clinical syndromes. A comprehensive understanding of the clinical, pathological, and variable imaging manifestations of pheochromocytoma can help radiologists make an accurate diagnosis. This article reviews various special imaging features of pheochromocytoma and pheochromocytoma-related diseases.

Micturition-triggered severe headache associated with bladder paraganglioma: A case report

BACKGROUND

Paragangliomas are rare neuroendocrine tumors, especially in the bladder. Although many paragangliomas are non-functional, functioning paragangliomas present with many non-specific signs and symptoms, such as hypertension and headache, complicating their diagnosis. Here, we report a case of micturition-induced severe headache associated with a bladder paraganglioma.Case description: This report describes a severe headache disorder triggered by micturition and associated with a bladder paraganglioma in a middle-aged woman. Her pain occurred consistently after micturition, beginning from the left side of the nose and gradually extended to the forehead and the parietal and occipital regions. The headaches lasted 5-10 min. Removal of the paraganglioma completely eliminated the patient's pain syndrome.

CONCLUSION

This case elucidates the association between micturition-triggered headaches and bladder paragangliomas. The presence of a post-micturition severe headache should suggest the possibility of a bladder paraganglioma.

Anaesthetic challenges in perioperative management of thoracic paraganglioma in an 8-year-old child

Pheochromocytomas (PCC) are catecholamine-secreting tumours that arise from chromaffin cells of the sympathoadrenal system. These rare catecholamine-secreting tumours arising from adrenal glands are termed as PCC and those from extra--adrenal sites are termed paraganglioma (PGL). Thoracic PGL is very rarely found. we report the anaesthetic challenges and management of an 8-year-old child with functional thoracic PGL and its successful outcome.

Antioxidant Barrier and Oxidative Damage to Proteins, Lipids, and DNA/RNA in Adrenal Tumor Patients

This study is the first to assess redox balance, glutathione metabolism, and oxidative damage to RNA/DNA, proteins, and lipids in the plasma/serum and urine of patients with adrenal masses. The study included 70 patients with adrenal tumors divided into three subgroups: incidentaloma (n = 30), pheochromocytoma (n = 20), and Cushing's/Conn's adenoma (n = 20), as well as 60 healthy controls. Blood and urine samples were collected before elective endoscopic adrenalectomy. Antioxidant defense capacity was significantly decreased (serum/plasma: superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH), uric acid (UA); urine: SOD, GSH, UA) in patients with adrenal masses. The oxidative damage to proteins (advanced glycation end products (AGE), advanced oxidation protein products (AOPP)) and lipids (lipid hydroperoxides (LOOH), and malondialdehyde (MDA)) was higher in the plasma and urine of these patients. Plasma MDA and DNA/RNA oxidation products, with high sensitivity and specificity, can help to diagnose pheochromocytoma. This biomarker differentiates patients with pheochromocytoma from Cushing's/Conn's adenoma as well as from heathy controls. Plasma RNA/DNA oxidation was also positively correlated with urine metanephrine. Oxidative stress can play a crucial role in adrenal tumors. However, further studies are required to clarify the role of redox signaling in adrenal masses.

Pheochromocytoma/paraganglioma crisis: case series from a tertiary referral center for pheochromocytomas and paragangliomas

Pheochromocytoma/paraganglioma (PPGL)-induced catecholamine crisis is a rare endocrine emergency leading to life-threatening hemodynamic instability causing end-organ damage or dysfunction. As it is associated with a significant mortality rate of approximately 15%, recognizing the signs and symptoms and making the appropriate diagnosis are critical. For this purpose, we report the clinical course of the crisis in four out of a total of six patients with a PPGL crisis from a cohort of 199 PPGL patients of a single tertiary referral center for PPGL patients in the Netherlands diagnosed between 2002 and 2020. Successful treatment of a PPGL crisis demands prompt diagnosis, vigorous pharmacological therapy, and emergency tumor removal if the patient continues to deteriorate.

Genetic Variants in Patients with Multiple Head and Neck Paragangliomas: Dilemma in Management

Multiple head and neck paragangliomas (HNPGLs) are neuroendocrine tumors of a mostly benign nature that can be associated with a syndrome, precipitated by the presence of a germline mutation. Familial forms of the disease are usually seen with mutations of SDHx genes, especially the SDHD gene. SDHB mutations are predisposed to malignant tumors. We found 6 patients with multiple tumors amongst 30 patients with HNPGLs during the period of 2016 to 2021. We discuss the phenotypic and genetic patterns in our patients with multiple HNPGLs and explore the management possibilities related to the disease. Fifty percent of our patients had incidental findings of HNPGLs. Twenty-one biochemically silent tumors were found. Four patients had germline mutations, and only one had a positive family history. Three out of five underwent surgery without permanent complications. Preventative measures (genetic counselling and tumor surveillance) represent the gold standard in effectively controlling the disease in index patients and their relatives. In terms of treatment, apart from surgical and radiotherapeutic interventions, new therapeutic measures such as gene targeted therapy have contributed very sparsely. With the lack of standardized protocols, management of patients with multiple HNPGLs still remains very challenging, especially in those with sporadic or malignant forms of the disease.

Bioinformatic analysis of differentially expressed genes as prognostic markers in pheochromocytoma and paraganglioma tumors

The pathogenesis of pheochromocytoma and paraganglioma (PCPG) catecholamine-producing tumors is exceedingly complicated. Here, we sought to identify important genes affecting the prognosis and survival rate of patients suffering from PCPG. We analyzed 95 samples obtained from two microarray data series, GSE19422 and GSE60459, from the Gene Expression Omnibus (GEO) repository. First, differentially expressed genes (DEGs) were identified by comparing 87 PCPG tumor samples and eight normal adrenal tissue samples using R language. The GEO2R tool and Venn diagram software were applied to the Database for Annotation, Visualization and Integrated Discovery (DAVID) to analyze Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and Gene Ontology (GO). We further employed Cytoscape with the Molecular Complex Detection (MCODE) tool to make protein-protein interactions visible for the Search Tool for Retrieval of Interacting Genes (STRING). These procedures resulted in 30 candidate DEGs, which were subjected to Kaplan-Meier analysis and validated by Gene Expression Profiling Interactive Analysis (GEPIA) to determine their influence on overall survival rate. Finally, we identified ALDH3A2 and AKR1B1, two genes in the glycerolipid metabolism pathway, as being particularly enriched in PCPG tumors and correlated with T and B tumor-infiltrating immune cells. Our results suggest that these two DEGs are closely associated with the prognosis of malignant PCPG tumors.

Case Report: Totally Laparoscopic Resection of Retroperitoneal Paraganglioma Masquerading as a Duodenal Gastrointestinal Stromal Tumor

Introduction: Retroperitoneal paraganglioma (RPGL) is a rare clinical tumor derived from the retroperitoneal sympathetic paraganglion tissue. Since RPGLs are locate deeply and have no specific symptoms and imaging manifestations at the early stage, which easily causes missed diagnosis or misdiagnosis. In addition, reports on totally laparoscopic resection of RPGLs are scarce due to their close proximity to large vessels, giant size, uncertain location, and unknown malignant status.

Case Presentation: We present here the case of totally laparoscopic resection of a 6.4 × 5.4 cm RPGL that was discovered during a workup for discomfort and upper abdominal pain in a 68-year-old female patient, mimicking a gastrointestinal stromal tumor (GIST) of the duodenum, Which was confirmed as a RPGL based on the histopathological and immunohistochemical findings.

Conclusions: RPGL is a rare tumor, and the transperitoneal laparoscopic approach for the RPGL is a safe, applicable method with less trauma and quick recovery, which is worth clinical popularizing and application. Moreover, the survival prognosis of RPGL patients are related to metastasis, and lifelong follow-up should be emphasized.

Diagnosis of a 09 cm pheochromocytoma mistaken to be an intramesenteric pancreatic tumor: Case report complying with the scare guidelines

INTRODUCTION

Pheochromocytoma is an adrenal medullary tumor of the chromaffin cells first described in 1886, remains an entity not fully discovered that case reports keep showing its diversity in clinical presentation, diagnosis methods treatment and follow up challenges.

CASE PRESENTATION

We report the case of a 47 year old woman with complaining from abdominal pain and major weightless with a 09 cm tumor of the body of the pancreas viewed in imaging with no hormonal secretion but high levels of chromogranine A open surgery conducted that revealed the tumor to be located between the adrenal medulla and the Aorta misleading the team between an adrenal tumor or a zuckerkandl body tumor. The hemodynamic changes after manipulation of the tumor and the histopathology confirming the diagnosis of pheochromocytoma. Our main surprise was the aspect of the tumor bombing in the peritoneal cavity firstly thought to be mesenteric tumor; and the stability of the patient with no premedication until the tumor had been manipulated, enlarging the hypothesis about catecholamine secretion of these tumor.

DISCUSSION

The diagnosis is basically simple when the tumor expresses its catecholamines by biomarkers testing, an imaging. Functional imaging should be used to locate the tumor or its metastasis, the sequence of testing or imaging can vary either it's a symptomatic tumor or an incidentaloma. Preoperative measures should be taken so no major preoperative complications and the main treatment is the tumor complete resection CONCLUSION: The malignancy of the pheochromocytoma is no near to be reliably identified which imposes a lifetime follow up of these patients as for metastasis were described even after 40 years after diagnosis.

Pheochromocytoma as a cause of repeated acute myocardial infarctions, heart failure, and transient erythrocytosis: A case report and review of the literature

BACKGROUND

Pheochromocytoma is a rare catecholamines-secreting tumor arising from chromaffin cells in the adrenal medulla. It classically presents with paroxysmal hypertension, headaches, palpitations, sweating, and metabolic disorders. Atypical presentations such as acute myocardial infarction, heart failure, cardiomyopathy, stroke, and transient erythrocytosis have been infrequently documented.

CASE SUMMARY

We describe the case of a 72-year-old man diagnosed with pheochromocytoma presenting with non-ST segment elevation myocardial infarction, heart failure, and transient erythrocytosis with nonobstructed coronary arteries. This was his second heart attack. The patient was previously diagnosed with myocardial infarction, and an immense mass was found on the left adrenal gland 3 years prior. Based on clinical and laboratory findings, a diagnosis of pheochromocytoma was confirmed. His coronary angiogram showed nonobstructed coronary arteries except for a myocardial bridge in the left anterior descending branch. This was a form of type-2 myocardial infarction. The myocardial cell lesions were caused by sudden secretion of catecholamines by the pheochromocytoma. Even more atypically, his hemoglobin level was obviously elevated at admission, but after a few days of treatment with an alpha-adrenergic receptor blocker, it dropped to normal levels without additional treatment.

CONCLUSION

Pheochromocytoma may be a cause of acute myocardial infarction, heart failure, and transient erythrocytosis.

THE ROLE OF TUMOR-SEEKING RADIOPHARMACEUTICALS IN THE DIAGNOSIS AND MANAGEMENT OF ADRENAL TUMORS

Context

The variety of tumor-seeking radiopharmaceuticals, which are currently in clinical use, may have a potential role as imaging agents for adrenal gland tumors, due to physiological characteristics of this organ.

Objective

The purpose of this study was to evaluate the diagnostic potential of ^99mTc-HYNIC-TOC, ^99mTc(V)-DMSA, and ^99mTc-MIBI in the assessment of adrenal tumors, by correlating with imaging findings and histopathologic results.

Design

The research is designed as a cross-sectional prospective study.

Patients and method

The study included 50 patients with adrenal tumors (19 hormone-secreting and 31 nonfunctioning) and 23 controls without adrenal involvement. In all patients, single-photon emission computed tomography (SPECT) was performed, using qualitative and semiquantitative analysis. The tumor to non-tumor tracer uptake was conducted by using a region-of-interest technique. Adrenal to background (A/B) ratio was calculated in all cases.

Results

^99mTc-HYNIC-TOC scintigraphy showed a high statistical significance between A/B ratios, while other two tracers resulted in a lower sensitivity, specificity and accuracy. Futhermore, ^99mTc-HYNIC-TOC could have a high diagnostic yield to detect adrenal tumors (the receiver-operating-characteristic curve analysis, A/B ratio cut-off value of 8.40).

Conclusion

A semiquantitative SPECT analysis showed that ^99mTc-HYNIC-TOC is a highly sensitive tumor-seeking agent for the accurate localization of adrenal tumors.

Perioperative management of pheocromocytoma/ paraganglioma: a comprehensive review

Pheochromocytomas are rare neuroendocrine neoplasms that require adequate preoperative evaluation in order to prevent and lessen the serious complications of catecholamine hypersecretion. Preoperative management contributes to reducing morbidity and mortality rates in patients who have not been diagnosed with this condition and undergo any surgery. However, current mortality seems to be lower, a fact attributed to preoperative management with alpha blockers.

Tumors presenting in both pediatric and adult patients: a case-based review of pathology and imaging features for the radiologist

Various pathologic neoplasms present in both childhood and adulthood. Multiple environmental and genetic factors with different targets at different ages have been implicated in prior literature. These tumors include Multi-Locular Cystic Renal Tumors (MCRT), Adrenocortical Carcinomas, Paragangliomas, Hepatic Hemangiomas, and Medullary Renal Cell Carcinomas. The pertinent imaging, pathological, and clinical features of these select entities are discussed to assist the General and Pediatric Radiologist in accurate interpretation and treatment planning.

An Adrenal Incidentaloma Diagnosed as Dopamine-Secreting Pheochromocytoma: A Case Report

BACKGROUND

Dopamine-secreting pheochromocytomas are exceedingly rare.

CASE PRESENTATION

A 28-year-old woman, who was admitted due to 4 hours of acute-onset abdominal pain, detected an adrenal mass incidentally. She was almost asymptomatic without a known family history. Laboratory assessments showed significant increases in dopamine levels of serum and 24-h urinary. By using preoperative a-adrenergic receptor blockers, she developed orthostatic hypotension and palpitations. When she underwent laparoscopic left adrenalectomy, she experienced rapid cyclic fluctuations in systolic blood pressure from 90 mmHg to 200 mmHg. Postoperatively, she exhibited prolonged hypotension, requiring vasopressor therapy and fluid replacement. According to histopathological diagnosis, it was a pheochromocytoma. Dopamine levels in 24-h urine and serum decreased to normal after operation. Analysis of specific gene SDHB, SDHD, RET, VHL and NF1 detected no pathogenic mutations.

CONCLUSION

Patients with dopamine-secreting pheochromocytomas are mostly asymptomatic, leading to a significant delay in diagnosis. There is a large possibility for dopamine-secreting pheochromocytomas to show a malignant tendency than the adrenergic and noradrenergic phenotypes. The a-adrenergic receptor blocker is not indicated for preoperative medical treatment because it can cause hypotension and cardiovascular failure. Calcium channel blockers or metyrosine may be better alternatives. All patients with pheochromocytomas should receive targeted genetic testing based on specific clinical features. SDHB, SDHD, RET, VHL and NF1 mutations are suggested for genetic testing of adrenal dopamine-secreting pheochromocytomas.

Abdominal Ultrasound in the Detection of an Incidental Paraganglioma

Paraganglioma is a tumor that originates from neuroendocrine cells of the sympathetic or parasympathetic systems. Patients may suffer from headaches, palpitations, diaphoresis, and hypertension due to catecholamine excess or symptoms from the mass effect of the tumor. In the absence of typical symptoms of catecholamine excess, the diagnosis of a nonfunctional paraganglioma is often delayed. Herein, we report a case of a 63-year-old female patient with a nonfunctional paraganglioma which is an accidental finding during investigation of a fever. Abdominal ultrasonography incidentally detected this lesion as a complex, solid, cystic mass in the left suprarenal retroperitoneum.

Prevention and Management of Hormonal Crisis during Theragnosis with LU-DOTA-TATE in Neuroendocrine Tumors. A Systematic Review and Approach Proposal

Neuroendocrine tumors (NETs) frequently overexpress somatostatin receptors (SSTR) on their cell surface. The first-line pharmacological treatment for inoperable metastatic functioning well-differentiated NETs are somatostatin analogs. On second line, Lu-DOTA-TATE (177Lu-DOTA0 Tyr 3 octreotate) has shown stabilization of the disease and an increase in progression free survival, as well as effectiveness in controlling symptoms and increasing quality of life. The management of functional NETs before and during LU-DOTA-TATE treatment is specially challenging, as several complications such as severe carcinoid and catecholamine crisis have been described. The aim of this review is to establish practical guidance for the management and prevention of the most common hormonal crises during radionuclide treatment with Lu-DOTA-TATE: carcinoid syndrome (CS) and catecholamine hypersecretion, as well as to provide a brief commentary on other infrequent metabolic complications. To establish a practical approach, a systematic review was performed. This systematic review was developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and conducted using MEDLINE (accessed from PubMed), Google Scholar and ClinicalTrials.gov. Literature searches found 449 citations, and finally nine were considered for this systematic review.

Pheochromocytoma and Paraganglioma: From Epidemiology to Clinical Findings

Pheochromocytomas (PCC) and paragangliomas (PGL) are rare neuroendocrine tumors. Pheochromocytomas arise from chromaffin cells in the adrenal medulla, and PGLs arise from chromaffin cells in the ganglia of the autonomic nervous system. Paragangliomas originate from sympathetic or parasympathetic ganglia in the abdomen, thorax, and pelvis. The majority of PCC and sympathetic PGL are endocrine active tumors causing clinical symptoms by secreting excess catecholamines (norepinephrine, epinephrine, dopamine) and their metabolites. The incidence of PCC and PGL ranges between 2 and 8 per million, with a prevalence between 1:2500 and 1:6500. It peaks between the 3rd and 5th decades of life, and approximately 20% of cases are pediatric patients. The prevalence among patients with hypertension in outpatient clinic ranges between 0.1-0.6% in adults and between 2-4.5% in the pediatric age group. 10-49% of these tumors is detected incidentally in imaging techniques performed for other reasons. However, 4-8% of adrenal incidentalomas are PCCs. Of these neuroendocrine tumors, 80-85% are PCCs and 15-20% are PGLs. Up to 40% of patients with PCC and PGL has disease-specific germline mutations and the situation is hereditary. Of 60% of the remaining sporadic patients, at least 1/3 has a somatic mutation in predisposing genes. 8% of the sporadic cases, 20-75% of the hereditary cases, 5% of the bilateral, adrenal cases, and 33% of the extra-adrenal cases at first presentation are metastatic. Although PCCs and PGLs have scoring systems for histological evaluation of the primary tumor, it is not possible to diagnose whether the tumor is malignant since there is no histological system approved for the biological aggressiveness of this tumor group. Metastasis is defined as the presence of chromaffin tissue in non-chromaffin organs, such as lymph nodes, liver, lungs and bone. Although most of the PCC and PGL are benign, the metastatic disease may develop in 15-17%. Metastatic disease is reported between 2-25% in PCCs and 2.4-60% in PGLs. The TNM staging system of the American Joint Committee on Cancer (AJCC) was developed to predict the prognosis, based on the specific anatomical features of the primary tumor and the occurrence of metastasis.

Endoscopic Resection of Functional Paraganglioma of the Pterygopalatine Fossa: A Case Report

Functional paraganglioma is a rare tumor that secretes the catecholamine which is able to cause secondary hypertension. Surgical resection is the only curative treatment modality for this tumor, which can correct the secondary hypertension. The pterygopalatine fossa is a small retromaxillary space which contains a neurovascular bundle that crosses the middle cranial fossa to the nasal cavity, nasal septum, and oral cavity. To our knowledge, two cases have been reported for functional paraganglioma involving the pterygopalatine fossa removed by surgery. We present a patient who had a catecholamine-secreting paraganglioma in the pterygopalatine fossa, which is the first case successfully resected with an endoscopic approach.

Germline variant in REXO2 is a novel candidate gene in familial pheochromocytoma

Pheochromocytoma (PCC) is a rare, mostly benign tumour of the adrenal medulla. Hereditary PCC accounts for ~35% of cases and has been associated with germline mutations in several cancer susceptibility genes (e.g., KIF1B, SDHB, VHL, SDHD, RET). We performed whole-exome sequencing in a family with four PCC-affected patients in two consecutive generations and identified a potential novel candidate pathogenic variant in the REXO2 gene that affects splicing (c.531-1G>T (NM 015523.3)), which co-segregated with the phenotype in the family. REXO2 encodes for RNA exonuclease 2 protein and localizes to 11q23, a chromosomal region displaying allelic imbalance in PCC. REXO2 protein has been associated with DNA repair, replication and recombination processes and thus its inactivation may contribute to tumorigenesis. While the study suggests that this novel REXO2 gene variant underlies PCC in this family, additional functional studies are required in order to establish the putative role of the REXO2 gene in PCC predisposition.

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.

A Guide to Pheochromocytomas and Paragangliomas

Pheochromocytomas and extra-adrenal paragangliomas are rare neuroendocrine neoplasms with characteristic histologic and immunohistochemical features. These tumors can arise in several anatomic locations, necessitating that their diagnostic recognition extends beyond the realm of endocrine disorders. A practical and reproducible risk stratification system for these tumors is still in development. In this rapidly evolving era of molecular medicine, it is essential for pathologists to equip themselves with a framework for understanding the classification of paragangliomas and pheochromocytomas and be informed of how they might advise their colleagues with regard to prognostication and appropriate follow-up.