Laparoscopic and retroperitoneoscopic treatment of pheochromocytomas and retroperitoneal paragangliomas: results of 161 tumors in 126 patients

Management of Pheochromocytomas and Paragangliomas

Pheochromocytomas and paragangliomas are distinctive neuroendocrine tumors which frequently produce excess catecholamines with resultant cardiovascular morbidity. These tumors have a strong genetic component, with up to 40% linked to hereditary pathogenic variants; therefore, germline genetic testing is recommended for all patients. Surgical resection offers the only potential cure in the case of localized disease. Given the potential for catecholaminergic crises, appropriate perioperative management is crucial, and all patients should undergo alpha-adrenergic blockade before resection. Therapeutic options for metastatic disease are limited and include surgical debulking, radiopharmaceutical therapies, and conventional chemotherapy.

Outcome of Partial Adrenalectomy in MEN2 Syndrome: Personal Experience and Systematic Review of Literature

Background: Partial adrenalectomy (PA) is an alternative option to total adrenalectomy for the treatment of hereditary pheochromocytoma (PHEO) to preserve cortical function and avoid life-long steroid replacement. The aim of this review is to summarize current evidence in terms of clinical outcome, recurrence, and corticosteroid therapy implementation after PA for MEN2-PHEOs. Material and Methods: From a total of 931 adrenalectomies (1997-2022), 16 of the 194 patients who underwent surgical treatment of PHEO had MEN2 syndrome. There were six patients scheduled for PA. MEDLINE^®, EMBASE^®, Web of Science, and Cochrane Library were searched for English studies from 1981 to 2022. Results: Among six patients who underwent PA for MEN2-related PHEO in our center, we reported two with bilateral synchronous disease and three with metachronous PHEOs. One recurrence was registered. Less than 20 mg/day Hydrocortison therapy was necessary in 50% of patients after bilateral procedures. Systematic review identified 83 PA for MEN2-PHEO. Bilateral synchronous PHEO, metachronous PHEO and disease recurrence were reported in 42%, 26%, and 4% of patients, respectively. Postoperative steroid implementation was necessary in 65% of patients who underwent bilateral procedures. Conclusions: PA seems to be a safe and valuable option for the treatment of MEN2-related PHEOs, balancing the risk of disease recurrence with the need for corticosteroid therapy.

Simultaneous bilateral laparoscopic cortical-sparing adrenalectomy for bilateral pheochromocytomas in multiple endocrine neoplasia type 2

Purpose

This study aimed to assess the feasibility of synchronous bilateral laparoscopic or open cortical-sparing adrenalectomy (SB-LCSA or SB-OCSA) for bilateral pheochromocytomas (bPHEOs) in multiple endocrine neoplasia type 2 (MEN2).

Methods

Altogether, 31 patients (54.8% were women) were diagnosed with MEN2-related bPHEOs, and 29 of them underwent varying specific adrenalectomies. We systematically analyzed and evaluated their clinical profiles, mutation types, tumor histopathological features, and follow-up records.

Results

All 31 patients with bPHEOs presented with RET-C634 (90.3%) and RET-M918T (9.7%) mutations, and the median age at initial presentation was 38 years (range, 23-78). bPHEOs were synchronous in 27 patients and metachronous in 4 (12.9%) patients. In total, 29 patients underwent initial cortical-sparing adrenalectomy (CSA) including 23 (79.3%) undergoing synchronous bilateral CSA (18 SB-LCSA and 5 SB-OCSA) and 6 (20.7%) undergoing metachronous CSA. SB-LCSA and synchronous surgery were associated with less bleeding volume and shorter length of hospital stay than SB-OCSA and metachronous surgery (all P's < 0.05). Corticosteroid replacement treatment was necessary for 14 patients (45.2%) after bilateral CSA. During a median follow-up period of 7 years (range, 1.8-23), three of these patients (10.3%) had a recurrent disease that required reoperation.

Conclusion

SB-LCSA is feasible for treating synchronous bPHEOs and should be recommended as a prioritized surgical approach.

Total versus partial adrenalectomy in bilateral pheochromocytoma - a systematic review and meta-analysis

BACKGROUND

In patients with bilateral pheochromocytoma, partial adrenalectomy offers the chance to preserve adrenal function and avoid the need for lifelong steroid supplementation. However, the risk of tumour recurrence raises questions about this procedure. The aim of our study was to compare partial and total adrenalectomy in bilateral pheochromocytoma through a systematic review with meta-analysis.

METHODS

A systematic search was carried out using databases (MEDLINE, EMBASE, Scopus, Web of Science, CENTRAL) and registers of clinical trials (ClinicalTrials.gov, European Trials Register, WHO International Trials Registry Platform). This meta-analysis included studies up to July 2022 without language restrictions. A random effects model meta-analysis was performed to assess the risk of tumor recurrence, steroid dependence and morbidity in these patients.

RESULTS

Twenty-five studies were included in the analysis involving 1444 patients. The relative risk (RR) of loss of adrenal hormone function during follow-up and the need for steroid therapy was 0.32 in patients after partial adrenalectomy: RR 0.32, 95% Confidence Interval (CI): 0.26-0.38, P < 0.00001, I2 = 21%. Patients undergoing partial adrenalectomy had a lower odds ratio (OR) for developing acute adrenal crisis: OR 0.3, 95% CI: 0.1-0.91, P=0.03, I2 = 0%. Partial adrenalectomy was associated with a higher risk of recurrence than total adrenalectomy: OR 3.72, 95% CI: 1.54-8.96, P=0.003, I2 = 28%.

CONCLUSION

Partial adrenalectomy for bilateral pheochromocytoma is a treatment that offers a chance of preserving adrenal hormonal function, but is associated with a higher risk of local tumor recurrence. There was no difference for the risk of metastasis and in overall mortality among the group with bilateral pheochromocytomas undergoing total or partial adrenalectomy. This study is in line with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and AMSTAR (A Measurement Tool to Assess Systematic Reviews) Guidelines (10, 11).

SYSTEMATIC REVIEW REGISTRATION

https://osf.io/zx3se.

Correlation between the size of pheochromocytoma and the level of metanephrines

Objective. Pheochromocytomas (PHEO) and paraganglioma (PGLs) are rare neuroendocrine catecholamine-producing tumors that arise from the chromaffin cells of either the adrenal medulla or extra-adrenal paraganglionic tissues. Despite the recent advances in imaging technologies, biochemical evidence of excessive catecholamine production by the tumor is considered the most important test for the diagnosis of these tumors. The aim of the present study is to investigate the role of the catecholamine metabolites (normetanephrine and metanephrine) levels in the diagnosis of PHEO/PGLs and to evaluate if their levels correlate with the size of these tumors. Patients and Methods. Twenty-five patients were included in the study during the time period of 10 years. Their data were compared with another set of 25 patients to obtain the sensitivity and specificity of metanephrine and normetanephrine in the diagnosis of PHEO/PGLs. The tumor size was reviewed in every patient to obtain the correlation coefficient between the tumor sizes and the plasma/24-hour urinary metanephrine levels. Results. The sensitivity and specificity rates for plasma metanephrine were 80-92% and 92-96%, respectively; while for 24-hour urinary metanephrine were 80-90% and 95-100%, respectively. We found a strong positive relationship between the tumor size and the plasma levels of normetanephrine (r=0.518, p<0.01), and metanephrine (r=0.577, p<0.01). While the relation with the 24-hour urinary concentrations of normetanephrine (r=0.384, p=0.01) and 24-h urinary meta-nephrine (r=0.138, p<0.01) was low. Conclusion. The determination of plasma and 24-hour urinary levels of metanephrines is a reliable test for the diagnosis of PHEO, as they are continuously produced by the tumor cells in contrast to catecholamines.

Retroperitoneoscopic resection of a primary retroperitoneal paraganglioma occurring between the aorta and vena cava: A case report

A 67-year-old man presented with lower limb weakness, palpitations, and insomnia. His urinary total metanephrine and normetanephrine levels were high. Computed tomography showed a 48 × 34-mm oval mass on the dorsal side of the pancreas and portal vein between the aorta and vena cava. Because of the tumor location, we performed laparoscopic surgery using a retroperitoneal approach. We described a case of a patient with primary retroperitoneal paraganglioma between the aorta and vena cava who underwent retroperitoneoscopic resection. Our case suggests that this procedure can be safely performed.

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.

Predicting surgical outcome in posterior retroperitoneoscopic adrenalectomy with the aid of a preoperative nomogram

BACKGROUND

Posterior retroperitoneoscopic adrenalectomy (PRA) has several advantages over transperitoneal laparoscopic adrenalectomy (TLA) regarding operative time, blood loss, postoperative pain, and recovery. However, it can be a technically challenging procedure. To improve patient selection for PRA, we developed a preoperative nomogram to predict operative time.

METHODS

All consecutive patients with tumors of ≤ 7 cm and a body mass index (BMI) of < 35 kg/m2 undergoing unilateral PRA between February 2011 and March 2020 were included in the study. The primary outcome was operative time as surrogate endpoint for surgical complexity. Using ten patient variables, an optimal prediction model was created, with a best subsets regression analysis to find the best one-variable up to the best seven-variable model.

RESULTS

In total 215 patients were included, with a mean age of 52 years and mean tumor size of 2.4 cm. After best subsets regression analysis, a four-variable nomogram was selected and calibrated. This model included sex, pheochromocytoma, BMI, and perinephric fat, which were all individually significant predictors. This model showed an ideal balance between predictive power and applicability, with an R2 of 38.6.

CONCLUSIONS

A four-variable nomogram was developed to predict operative time in PRA, which can aid the surgeon to preoperatively identify suitable patients for PRA. If the nomogram predicts longer operative time and therefore a more complex operation, TLA should be considered as an alternative approach since it provides a larger working space. Also, the nomogram can be used for training purposes to select patients with favorable characteristics when learning this surgical approach.

A case of retroperitoneal venous malformation resected by laparoscopic surgery

Introduction

Among vascular malformations, venous malformations are the most common type. Among these, retroperitoneal venous malformations are extremely rare.

Case presentation

A 60‐year‐old woman was diagnosed with a retroperitoneal tumor 4.5 cm in diameter by abdominal computed tomographic scan. We had difficulty judging whether the tumor was benign or malignant. We performed laparoscopic surgery in order to remove the tumor and make a precise diagnosis. The pathological diagnosis was a venous malformation.

Conclusion

Venous malformation located in the retroperitoneum is very rare, and there were few cases that could be removed by laparoscopic surgery. Laparoscopic surgery may be beneficial both for treatment and diagnosis of patients with a small retroperitoneal venous malformation.

Preoperative Alpha-Blocker Therapy in Patients with Missed Preoperative Diagnosis of Extra-Adrenal Retroperitoneal Paraganglioma Undergoing Resection: A Retrospective Study of 167 Cases at a Single Center

INTRODUCTION

Preoperative α-adrenergic blockade is thought to decrease perioperative risks and mortality in surgeries for adrenal pheochromocytoma. However, there are limited data on the efficacy of α-blockers in surgeries for retroperitoneal paragangliomas. The aim of this study was to evaluate the effects of the preoperative α-adrenergic blockade on outcomes in patients undergoing surgery for extra-adrenal retroperitoneal paraganglioma.

METHODS

We searched the clinical database for patients diagnosed with extra-adrenal retroperitoneal paraganglioma by postoperative histopathology in the General Hospital of People's Liberation Army in China from 2000 to 2017. We compared the preoperative status of patients, preoperative examination, preoperative preparation, intraoperative and postoperative cardiovascular events, intake and output, length of stay in the intensive care unit, length of hospital stays, and short-term outcomes between patients who received preoperative treatment with α-adrenergic blockade and those who did not.

RESULTS

Of the 167 patients enrolled in the study, 61 received preoperative α-adrenergic blockade therapy. Intraoperative heart rate elevation and highest heart rate were higher in patients undergoing tumor manipulation with preoperative α-adrenergic blockade than those who did not (p < 0.05). However, there were no significant differences between these 2 groups in terms of intraoperative blood pressure elevation and systolic blood pressure decrease following tumorectomy (p > 0.05). Moreover, there were no significant differences in postoperative complications and outcomes (p > 0.05).

CONCLUSION

Under the current medical practice, resection of extra-adrenal retroperitoneal paraganglioma can be successfully carried out with or without preoperative α-adrenergic blockade.

Tailored Approach in Adrenal Surgery: Retroperitoneoscopic Partial Adrenalectomy

The interest on partial adrenalectomy has steadily increased over the past twenty years. Adrenal pathologies are mostly benign, making an organ-preserving procedure attractive for many patients. The introduction of minimally invasive techniques played probably an important role in this process because they transformed a complex surgical procedure, related to the difficult access to the retroperitoneal space, into a simple operation improving the accessibility to this organ. In this review we summarize the role of partial retroperitoneoscopic adrenalectomy over the years and the current indications and technique.

Laparoscopic resection of aortocaval paraganglioma diagnosed by serial increase in urinary metanephrines after bilateral adrenalectomy in a patient with multiple endocrine neoplasia type 2A

INTRODUCTION

Although bilateral pheochromocytoma is prevalent in patients with multiple endocrine neoplasia type 2, extra-adrenal tumors rarely occur in the aortocaval area.

CASE PRESENTATION

A 35-year-old man with multiple endocrine neoplasia type 2A (RET codon Cys634Arg mutation) underwent bilateral adrenalectomy for metachronous pheochromocytoma. After bilateral adrenalectomy, urinary metanephrines decreased below the measurement sensitivity. The levels of urinary metanephrines were serially elevating to a peak of 187 ng/mgCr during the 11-year follow-up period; however, urinary normetanephrine levels remained almost stable. 123I-metaiodobenzylguanidine single-photon emission computed tomography revealed abnormal accumulation with a mass of 25 × 18 mm in diameter in the aortocaval space cranially to the renal vessels. The extra-adrenal paraganglioma was successfully resected using transperitoneal laparoscopic surgery.

CONCLUSION

The serial increase in urinary metanephrine levels was useful for the detection of the recurrent tumor in a patient who had undergone bilateral adrenalectomy.

Minimally invasive adrenalectomy for large pheochromocytoma: not recommendable yet? Results from a single institution case series

BACKGROUND

Minimally invasive adrenalectomy represents the treatment of choice of pheochromocytoma (PCC). For large or invasive PCCs, an open approach is currently recommended, in order to ensure complete tumor resection, prevent tumor rupture, avoid local recurrence, and limit perioperative hemodynamic instability. The aim of this study is to analyze perioperative outcomes of laparoscopic adrenalectomies (LAs) for large adrenal PCCs.

METHODS

All consecutive LAs for PCC performed at a single institution between 1998 and 2020 were included. Two groups were defined: lesions larger (group 1) and smaller (group 2) than 5 cm. Short-term outcomes were compared in order to find any significant difference between the two groups.

OUTCOMES

One hundred fourteen patients underwent LA during the study period: 46 for lesions larger and 68 for lesions smaller than 5 cm. No significant differences were found in patients' characteristics, median operative time, conversion rate, intraoperative hemodynamic and metabolic parameters, postoperative intensive care unit (ICU) admission rate, complications rate, and length of hospital stay. Long-term oncologic outcomes were similar, with a recurrence rate of 5.1% in group 1 vs 3.6% in group 2 (p = 1).

CONCLUSION

Minimally invasive adrenalectomy seems to be safe and effective even in large PCC. The recommendation to prefer an open approach for large PCCs should probably be reconsidered.

Feasibility and safety of the posterior retroperitoneoscopic approach in the resection of aortocaval and infrarenal paraganglioma: a single-center experience

BACKGROUND

The posterior retroperitoneoscopic approach (PRA) has been under attention as a method for resection of paraganglioma (PGL) for the past few years. However, only a few studies have explored the effectiveness and safety of the PRA for aortocaval and infrarenal PGL resection.

METHODS

We designed this retrospective study to investigate the safety and effectiveness of the PRA for aortocaval and infrarenal PGL resection in a single center. We retrospectively reviewed the medical records of patients who underwent PRA for PGL resection at our medical center from January 2006 to March 2021. Eight patients were enrolled, of whom six had aortocaval PGL. We investigated the surgical outcomes of enrolled patients.

RESULTS

The locations of the tumors in relation to the renal vein were: suprarenal in two (25.0%) patients, at the renal vein level in three (37.5%) patients, and infrarenal in three (37.5%) patients. The mean operative time of the enrolled patients was 101.5 ± 39.1 min. The mean postoperative stay was 3.5 ± 1.5 days, and the estimated blood loss was 31.3 ± 51.4 ml. There was one minor complication (chyle leakage), and two hypotensive events occurred during the surgery. Focusing on the results of the renal vein level and infrarenal PGL resection, the mean operative time, mean postoperative stay, and estimated blood loss of the patients were 109.2 ± 41.3 min, 3.5 ± 1.8 days, and 41.7 ± 56.4 ml, respectively.

CONCLUSION

The PRA for aortocaval and infrarenal PGL resection is feasible and safe. Additional data analysis and long-term follow-up are needed in the future.

Approach to pheochromocytoma and paraganglioma in children and adolescents: A retrospective clinical study from a tertiary care center

AIM

Pheochromocytoma (PCC) and paraganglioma (PGL) are rare tumors in childhood. They are catecholamine secreting tumors and present with signs or symptoms related to their excess. Most common signs and symptoms are hypertension, headache and diaphoresis. The management of children usually depend on experience of adulthood. This study is conducted to present the clinical characteristics, surgical management and outcome of childhood PCC and PGL in a tertiary care center.

MATERIAL AND METHODS

We reviewed clinical records of all patients operated for PCC and PGL between 2000 and 2020 retrospectively.

RESULTS

There were 18 children operated for PCC and PGL in the study period. The female to male ratio was 1:1. The median age at diagnosis was 13 (IQR, 9-15) years. The most common presenting symptoms were headache and diaphoresis. Hypertension was the most common sign. Three patients had von Hippel-Lindau (VHL). Tumors of two patients with VHL were detected during routine follow-up. Three patients had multifocal disease. Medical preparation for surgery was carried out in all patients. Antihypertensive treatments were administered preoperatively. Since the patients are at risk for postoperative hypotension due to chronic vasoconstriction and blood volume contraction, high salt diet was recommended. Intravenous normal saline at a rate of 3000 ml/m² body surface area per day was started for intravascular volume expansion preoperatively. The mean duration for preoperative medication to achieve normal blood pressure was 22 days (range, 16-30). Twenty-five tumors were excised in eighteen patients. One patient who had bone metastases on diagnosis and is on I¹³¹MIBG therapy. The median follow-up time was 5.6 years (range, 1 months - 21 years). Five patients reached adulthood during the study period. Four of these had recurrent metastases (n = 2) and new tumors (pancreatic neuroendocrine tumor, n = 1 and pancreatic neuroendocrine tumor and renal cell carcinoma, n = 1) after the age of 18.

CONCLUSION

Multidisciplinary approach is necessary to achieve safe surgical treatment and surveillance of PCC and PGL. Detection of associated familial cancer susceptibility syndromes and long-term follow-up is essential to detect late recurrences and new tumors.

Multidisciplinary practice guidelines for the diagnosis, genetic counseling and treatment of pheochromocytomas and paragangliomas

Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors that arise from chromaffin cells of the adrenal medulla and the sympathetic/parasympathetic neural ganglia, respectively. The heterogeneity in its etiology makes PPGL diagnosis and treatment very complex. The aim of this article was to provide practical clinical guidelines for the diagnosis and treatment of PPGLs from a multidisciplinary perspective, with the involvement of the Spanish Societies of Endocrinology and Nutrition (SEEN), Medical Oncology (SEOM), Medical Radiology (SERAM), Nuclear Medicine and Molecular Imaging (SEMNIM), Otorhinolaryngology (SEORL), Pathology (SEAP), Radiation Oncology (SEOR), Surgery (AEC) and the Spanish National Cancer Research Center (CNIO). We will review the following topics: epidemiology; anatomy, pathology and molecular pathways; clinical presentation; hereditary predisposition syndromes and genetic counseling and testing; diagnostic procedures, including biochemical testing and imaging studies; treatment including catecholamine blockade, surgery, radiotherapy and radiometabolic therapy, systemic therapy, local ablative therapy and supportive care. Finally, we will provide follow-up recommendations.

Evolution of surgical management for phaeochromocytoma over a 17-year period: an Australian perspective

BACKGROUND

Minimally invasive adrenalectomy and advances in anaesthetic techniques have transformed surgery for phaeochromocytoma. This 17-year review describes the evolution of phaeochromocytoma care in our unit.

METHODS

We performed a retrospective cohort review of all patients who underwent adrenalectomy for phaeochromocytoma from 2000 to 2016. Patients were divided into three time periods, early: 2000-2005 (n = 17), middle: 2006-2010 (n = 15) and late: 2011-2016 (n = 24). The posterior retroperitoneoscopic adrenalectomy was introduced in 2011. Demographics and clinicopathological details were extracted. Median values for nominal data were compared using Mann-Whitney U-test. A chi-squared test was used to compare categorical data.

RESULTS

Sixty-one adrenalectomies were performed on 56 patients: 19 open, 17 laparoscopic and 20 posterior retroperitoneoscopic adrenalectomies. The median length of operation decreased from 135 to 90 min from the early to the late time period (P > 0.05). Length of stay decreased from a median of 5 days in the early group to 1 day in the late group (P = 0.01). A total of 94.1% of the early period patients were admitted to the intensive care unit compared to 30.4% of the late group (P = <0.01). Need for post-operative vasopressors and blood transfusions was significantly reduced.

CONCLUSION

Over the 17-year period, the choice of operative technique has transitioned towards posterior retroperitoneoscopic adrenalectomy. Operative time, rate of intensive care unit admission, and admission length have all decreased without any increase in rates of complications.

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.

Local-Regional Recurrence of Pheochromocytoma/Paraganglioma: Characteristics, Risk Factors and Outcomes

OBJECTIVE

To study the characteristics, risk factors, and outcomes of local-regional recurrence of pheochromocytoma and paraganglioma (PPGL).

METHODS

Clinical data of 96 PPGL patients with local-regional recurrence and 112 patients without recurrence were retrospectively analyzed.

RESULTS

Recurrent patients exhibited a median recurrence time of 6.0 (4.0, 9.0) years after resection of the primary tumor. SDHB mutation [HR 4.1 (1.7, 9.5), p=0.001), primary tumor size ≥5cm [HR 2.3 (1.1, 4.7), p=0.028], and average Ki-67 count ≥3% in the primary tumor [HR 2.6 (1.4, 4.9), p=0.003] were independent predictors for recurrence of PPGL. Primary tumor sizes ≥5cm [HR 5.1 (1.7, 15.3), p=0.003] and average Ki-67 counts ≥3% of the primary tumor [HR 2.4 (1.1, 5.2), p=0.035] were independent predictors for recurrence of pheochromocytoma, while SDHB mutation [HR 4.6 (1.5, 13.9), p=0.007] was a predictor for paraganglioma recurrence. Among recurrent patients, 47% (45/96) had multiple nodules in recurrent sites, and 58% (56/96) had metastases, with 20% (19/96) being implantation metastases. The risk of metastases (42% vs. 25%, p=0.030) and death (15% vs. 8%, p=0.003) was significantly increased in untreated patients after recurrence compared with treated patients.

CONCLUSION

Long-term follow-up is necessary for all PPGL patients. Risk factors for recurrence of pheochromocytoma and paraganglioma differ, with primary tumor size and average Ki-67 count representing independent predictors for pheochromocytoma patients and SDHB mutations predicting paraganglioma recurrence. Although the treatment of recurrence can be difficult, patients should be treated once recurrence is detected as it decreases the risk of metastases and death.

Long-term outcomes of abdominal paraganglioma

Purpose

Paragangliomas (PGL) are rare neuroendocrine tumors derived from chromaffin cells of the autonomic nervous system. We aim to describe our experience and the long-term outcome of abdominal PGL over the last decade.

Methods

A retrospective review of patients diagnosed with PGL in our hospital between November 2005 and June 2017 was conducted. All nonabdominal PGL were excluded and the clinicopathological features and long-term outcomes of the patients were analyzed.

Results

A total of 46 patients were diagnosed with abdominal PGL. The average age of diagnosis was 55.4 years and there was no sex predilection. The average tumor size was 5.85 cm and they were predominantly located in the infrarenal position (50%). The mean follow-up period was 42 months (range, 1.8–252 months). All patients with metastases had Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) of ≥4. One patient presented with synchronous metastases while 2 developed local recurrence and distant metastases. One presented with only local recurrence. One patient died 5 years after diagnosis.

Conclusion

Abdominal PGL is a rare tumor with excellent long-term prognosis. Recurrence although uncommon, can occur decades after initial diagnosis. Long-term follow-up is therefore recommended for all patients with PGL, especially in patients with PASS of ≥4.

Approach to the Patient: Perioperative Management of the Patient with Pheochromocytoma or Sympathetic Paraganglioma

Pheochromocytomas and sympathetic paraganglioma (PPGL) are rare chromaffin cell tumors originating in the adrenal medulla and sympathetic paraganglia, respectively, which share the capacity to synthesize and release catecholamines. The incidence of PPGL has increased in recent years. Surgical resection is the only curative treatment for PPGL. Management of patients with PPGL is complex and should be done by a specialized multidisciplinary team in centers with broad expertise. Surgical resection of a PPGL is a high-risk procedure for which optimal pretreatment with antihypertensive drugs is required in combination with state-of-the-art surgical procedures and anesthesiological techniques. In this article we discuss the underlying evidence and the pros and cons of presurgical medical preparation. Finally, the areas of uncertainty and controversies in this field are addressed.

Long-term Functional and Oncologic Outcomes of Partial Adrenalectomy for Pheochromocytoma

OBJECTIVE

To evaluate the recurrence and functional outcomes in a primarily hereditary cohort of patients undergoing partial adrenalectomy for pheochromocytoma.

METHODS

A retrospective review from a prospectively managed database of patients undergoing partial adrenalectomy from 1995 to 2018 at the National Cancer Institute was performed. Local recurrence was defined as imaging evidence of a recurrent or de novo lesion on the operative side. Steroid dependency was defined as requiring daily steroid replacement at time of last follow-up.

RESULTS

One hundred and twenty-four partial adrenalectomies, removing 162 tumors, were performed in 107 patients. Most patients had a known hereditary predisposition to develop bilateral, multifocal, and recurrent pheochromocytoma. Median tumor size was 2 cm (interquartile range (IQR) 1.5-2.8). Median follow-up was 60 months (IQR 13-131). Local recurrence occurred in 17 patients (15.8%) and were managed with active surveillance or surgery. A single patient (1/106, 0.9%) developed metastatic spread of pheochromocytoma approximately 14 years after his first of 2 partial adrenalectomies and remains alive under active surveillance. Median time to recurrence was 71 months (IQR 26-127) with 10 patients (9.3%) requiring daily steroid replacement at time of last follow-up.

CONCLUSION

Partial adrenalectomy offers excellent oncologic and functional outcomes, sparing most patients from lifelong steroid replacement therapy. Recurrences can be easily managed with repeat surgery or active surveillance via functional work-up and imaging. Partial adrenalectomy remains the recommended surgical management for patients pre-disposed to development of bilateral, multifocal and recurrent pheochromocytoma.

Laparoscopic transperitoneal and retroperitoneal adrenalectomy: a 20-year, single-institution experience with an analysis of the learning curve and tumor size [lap transper and retroper adrenalectomy]

BACKGROUND

The superiority of laparoscopic transperitoneal (TP) versus retroperitoneal (RP) adrenalectomy is an ongoing debate.

METHODS

Data from 163 patients (TP: n = 135; RP: n = 28) undergoing minimally invasive adrenalectomy were analyzed. Both operative [intraoperative blood loss, previous abdominal surgery, conversion rate, operative time and tumor size] and perioperative [BMI (body mass index), ASA (American Society of Anesthesiologists) score, time of hospitalization, time of oral intake, histology and postoperative complications] parameters were compared. Both the learning curve (LC) and tumor size were analyzed.

RESULTS

We found significant differences in the mean operative time (p = 0.019) and rate of previous abdominal surgery (p = 0.038) in favor of TP. Significantly larger tumors were removed with TP (p = 0.018). Conversion rates showed no significant difference (p = 0.257). Also, no significant differences were noted for time of hospitalization, intraoperative blood loss and postoperative complications. In terms of the LC, we saw significant differences in previous abdominal surgery (p = 0.015), conversion rate (p = 0.011) and operative time (p = 0.023) in favor of TP. Large (LT) and extra-large tumors (ELT) were involved in 47 lesions (LT: 40 vs. ELT: 7), with a mean tumor size of 71.85 and 141.57 mm, respectively. Mean intraoperative blood loss was 64.47 ml vs. 71.85 ml, time of hospitalization was 5.10 vs. 4.57 days and mean operative time was 76.52 vs. 79.28 min for LT and ELT, respectively.

CONCLUSION

A shorter operative time and lower conversion rate in favor of TP were noted during the learning curve. TP proved to be more effective in the removal of large-, extra-large and malignant lesions. The RP approach was feasible for smaller, benign lesions, with a more prolonged learning curve.

Adrenal Tumors: Are Gender Aspects Relevant?

The distribution of malignant tumors is strongly related to gender due to sex-related organ and tissue differentiation. Neoplasias of the adrenal glands are relatively common and typically benign. Mainly based on our recently published contributions, we analyzed the influence of gender on type of tumors, complexity of surgery, and long-term outcome. Cortisol-secreting adrenal tumors are more often diagnosed in female patients, while the incidence of Conn's syndrome and pheochromocytoma is similar between male and female patients. Adrenalectomy is more difficult in male patients because of longer operating time and higher blood loss. The probability of cure in male patients with Conn's syndrome is significantly lower. Gender does not influence long-term results in adrenal hypercortisolism and pheochromocytomas.

Caveat for Vascular Surgeons: Lesson Learned from Acute Onset of a Rare Aortic Paraganglioma in a Young Boy

BACKGROUND

Paragangliomas (PGs) are rare neuroendocrine tumors arising from the extra-adrenal autonomic paraganglia that are tiny organs formed by bundles of neuroendocrine cells derived from the embryonic neural crest and capable of catecholamines secretion. Diagnosis and treatment of aortic PGs could be a challenging issue when they present as an emergency setup (sudden abdominal pain and radiological images resembling a vascular emergency).

CASE REPORT

We present a rare case of a 16-year-old man with a symptomatic and bleeding left para-aortic mass, treated in emergency with embolization, before a staged videolaparoscopic resection. Histology of the mass showed the presence of a large aortic PG.

CONCLUSIONS

In case of active bleeding, in emergency, vascular consultants are always involved. Sometimes, circumstances are very atypical; therefore, it is essential to keep in mind rare pathologies. In such settings, multidisciplinary approach is primary to obtain a prompt diagnosis and appropriate treatment.

Surgical approaches and results of treatment for hereditary paragangliomas

Paragangliomas (PGL) are rare neuroendocrine tumours; parasympathetic PGL are predominantly non-secreting and located at the skull base and neck, while sympathetic PGL are typically catecholamine-secreting and located at abdomino-pelvic level. Approximately 40% of PGL may be caused by germline mutations; hereditary variants should be suspected especially in case of positive family history, early onset, multifocal, or recurrent PGL. Significant genotype-phenotype correlation has been recognized, including syndromic presentation, location, multifocality and risk of malignancy. Surgical resection remains the only curative strategy, but the outcomes may be unsatisfactory because of surgical morbidity and recurrence rate. However, due to the rarity of the disease, most data derive from case-report or limited series. This paper was aimed to review the available literature on the epidemiology, diagnosis, clinical features, treatment of PGL in order to discuss the surgical approach and the results of treatment in hereditary PGL.

Indocyanine green fluorescence imaging during partial adrenalectomy

BACKGROUND

Indocyanine green (ICG) fluorescence imaging represents an emerging technology that facilitates the assessment of tissue vascularity, tissue distinction, and tumor localization during surgery. The aim of this study was to investigate the potential role of ICG imaging during laparoscopic partial adrenalectomy.

METHODS

Indocyanine fluorescence imaging was carried out during laparoscopic partial adrenalectomy for bilateral pheochromocytoma and bilateral Cushing's syndrome. A first bolus of 5 mg ICG was applied intravenously upon exposure of the retroperitoneal plane to identify the adrenal borders. The fluorescence was visualized using a Storz^® NIR/ICG endoscopic system. As the camera of this system detects NIR light as a blue signal, the well-vascularized adrenal tissue was expected to show a strong fluorescence in the blue color channel in contrast to the surrounding adipose tissue. Following partial adrenalectomy, a second bolus of 5 mg ICG was applied intravenously to evaluate the vascularity of the remaining adrenal tissue.

RESULTS

We investigated six adrenal glands from three patients undergoing bilateral partial adrenalectomy. The indication for surgery was pheochromocytoma in two patients and Cushing's syndrome with bilateral adenomas in one patient. Regarding left adrenalectomies, ICG imaging was helpful in visualizing the adrenal borders and the adrenal vein. Further, it facilitated the identification of the hypofluorescent pheochromocytoma and to resect the entire tumor. On the right side, due to the more apparent anatomy, ICG imaging did not contribute to the conduct of the operation. Four adrenal remnants showed a strong vascularization and two remnants were only reasonably vascularized.

CONCLUSION

ICG fluorescence may be helpful in guiding partial adrenalectomy and assessing the vascularity of remaining adrenal tissue.

Laparoscopic adrenalectomy: lateral transperitoneal versus posterior retroperitoneal approach - prospective randomized trial

INTRODUCTION

Laparoscopic adrenalectomy has become the gold standard of surgical treatment for benign adrenal masses. Two alternative surgical approaches are currently advocated: the lateral transperitoneal approach (LTA) and the posterior retroperitoneal approach (PRA). Several randomized trials have compared LTA to PRA, but most of them included small numbers of patients or had stringent inclusion criteria.

AIM

To compare clinical results of LTA and PRA endoscopic adrenalectomies for tumors < 8 cm with wide inclusion criteria.

MATERIAL AND METHODS

We randomized 77 patients to either LTA (n = 33) or PRA (n = 44). The groups were comparable in terms of age, gender proportions, body mass index, tumor size, clinical and pathological diagnosis. We analyzed duration of surgery, intraoperative blood loss, postoperative pain, length of hospital stay and postoperative morbidity.

RESULTS

The follow-up concerned 98.8% of patients and was on average 28 (8-47) months long. There were no conversions. We identified significantly lower intensity of pain assessed 24 h after surgery in the PRA group (3.4 ±1), as compared to LTA (4.2 ±1), with lower prevalence of shoulder pain (2.3% vs. 30.3%, respectively). Postoperative hospital stay was shorter in the PRA (1.14 ±0.4) than in the LTA (1.36 ±0.5) group. Perioperative morbidity concerned 4 patients in each group with pain requiring oral analgesia > 7 days.

CONCLUSIONS

To our knowledge this is the largest prospective randomized study comparing LTA to PRA. We demonstrated safety, efficacy and very low morbidity of both techniques. The PRA proved superior to LTA in terms of lower intensity of postoperative pain and shorter hospital stay.

Retroperitoneoscopic resection of retroperitoneal nonadrenal ganglioneuromas: our technique and clinical outcomes

OBJECTIVE

To report our experience of retroperitoneoscopic technique in semi-lateral decubitus position for the retroperitoneal nonadrenal ganglioneuromas in 18 patients, and to evaluate its clinical outcomes.

MATERIALS AND METHODS

From January 2012 to May 2016, 18 patients with retroperitoneal nonadrenal ganglioneuromas underwent retroperitoneoscopic resection. With the patients in semi-lateral decubitus position, a 4-port retroperitoneal approach was used. Data were collected on the tumor size, tumor location, perioperative outcomes, pathology, and lastknown disease status. We reviewed the operative videos to identify surgical tips and tricks.

RESULTS

All procedures were carried out successfully without converting to open surgery. The tumors had an average size of 5.2cm. The mean operative time was 86.5 min, with a mean estimated blood loss of 85.4mL. There were three patients suffering from intraoperative complications. Postoperatively, all patients achieved an uneventful recovery; the mean postoperative hospital stay was 5.5 days. The postoperative pathology revealed to be retroperitoneal ganglioneuromas. With a mean follow-up of 39.5 months, all patients were recurrence free. The review of the operative videos revealed several tips and tricks, including keeping peritoneum and posterior Gerota fascia intact to provide a favorable operative exposure of tumors, and placing the harmonic scalpel through different ports during tumor dissection.

CONCLUSIONS

With the patient in semi-lateral decubitus position and a 4-port retroperitoneal approach, retroperitoneoscopic resection of retroperitoneal nonadrenal ganglioneuroma is a feasible, effective, and safe procedure. This approach has distinct advantages including direct access to the tumor, optimal exposure of tumor and less intraperitoneal interference.

[Minimally invasive surgery of retroperitoneal paragangliomas : Synopsis of personal experiences]

Retroperitoneal paragangliomas are rare tumors with the characteristics of adrenal pheochromocytomas. They may occur sporadically or in conjunction with hereditary syndromes. Diagnostic methods in paragangliomas include testing of catecholamine secretion and imaging procedures. The first choice treatment is surgical removal, which in the author's opinion is preferably by minimally invasive approaches. Infrarenal paragangliomas should be excised using a laparoscopic transabdominal procedure. For suprarenal tumors the retroperitoneoscopic approach should be used.

[Genetics of pheochromocytoma and the relevance in surgery]

Chromaffin tumors, e.g. pheochromocytomas and paragangliomas are caused by germline mutations of several susceptibility genes in 30-40% of the patients. The corresponding syndromes are multiple endocrine neoplasia type 2 (MEN2, RET gene), von Hippel-Lindau disease (VHL), neurofibromatosis type 1 (NF1), paraganglioma syndrome types 1-5 (PGL1-5, SDHx gene) and familial pheochromocytoma due to mutations in the MAX and TMEM127 genes. Clinically, screening for such diseases should be carried out by clinical symptoms and mutation analyses. Important indications can be found in the history of patients and their families, young age of manifestation (<30 years), extra-adrenal localization and the presence of metastatic pheochromocytomas. Organ-preserving endoscopic adrenal operations are nowadays standard for hereditary pheochromocytomas. Previous studies have shown that the reoccurrence of tumors in residual tissue is rare and can occur many years later and that metastatic tumors arising from such recurrences are very rare. When a mutation is detected in a susceptibility gene, a multidisciplinary follow-up care tailored to each individual syndrome is essential.

65 YEARS OF THE DOUBLE HELIX: Genetics informs precision practice in the diagnosis and management of pheochromocytoma

Although the authors of the present review have contributed to genetic discoveries in the field of pheochromocytoma research, we can legitimately ask whether these advances have led to improvements in the diagnosis and management of patients with pheochromocytoma. The answer to this question is an emphatic Yes! In the field of molecular genetics, the well-established axiom that familial (genetic) pheochromocytoma represents 10% of all cases has been overturned, with >35% of cases now attributable to germline disease-causing mutations. Furthermore, genetic pheochromocytoma can now be grouped into five different clinical presentation types in the context of the ten known susceptibility genes for pheochromocytoma-associated syndromes. We now have the tools to diagnose patients with genetic pheochromocytoma, identify germline mutation carriers and to offer gene-informed medical management including enhanced surveillance and prevention. Clinically, we now treat an entire family of tumors of the paraganglia, with the exact phenotype varying by specific gene. In terms of detection and classification, simultaneous advances in biochemical detection and imaging localization have taken place, and the histopathology of the paraganglioma tumor family has been revised by immunohistochemical-genetic classification by gene-specific antibody immunohistochemistry. Treatment options have also been substantially enriched by the application of minimally invasive and adrenal-sparing surgery. Finally and most importantly, it is now widely recognized that patients with genetic pheochromocytoma/paraganglioma syndromes should be treated in specialized centers dedicated to the diagnosis, treatment and surveillance of this rare neoplasm.

Submucosal tunnel endoscopic resection for extraluminal tumors: a novel endoscopic method for en bloc resection of predominant extraluminal growing subepithelial tumors or extra-gastrointestinal tumors (with videos)

BACKGROUND AND AIMS

The management of subepithelial tumors with a predominant extraluminal growth pattern or extra-GI tumors can be challenging and traditionally requires a surgical resection that is not only invasive but may carry a significant risk of morbidity and mortality. We aimed to assess the feasibility, safety, and efficacy of a novel endoscopic technique termed submucosal tunnel endoscopic resection for extraluminal tumors (STER-ET).

METHODS

We prospectively enrolled patients who underwent STER-ET for GI subepithelial tumors with a predominant extraluminal growth pattern or extra-GI tumors located at the level of cardia or the proximal part of the lesser curvature of the stomach seen on cross-sectional imaging between January 2016 and March 2017.

RESULTS

Eight patients underwent STER-ET. The mean (± standard deviation) tumor size was 2.8 ± 0.6 cm and 2.3 ± 0.8 cm in longest and shortest dimension, respectively. The average procedure time was 67 ± 4.4 minutes. The rates of curative en bloc resection and en bloc retrieval was 100% and 87.5%, respectively. On final histology, 6 tumors were GI stromal tumors, 1 was a schwannoma, and 1 was a foregut cyst. Five patients had capnoperitoneum during the procedure and required abdominal decompression. One patient had a small mucosotomy successfully treated with a hemostatic clip. There were no major adverse events or deaths. The median length of hospital stay was 3 days. There was no residual tumor on surveillance imaging after a mean follow-up period of 10.0 ± 2.1 months.

CONCLUSIONS

STER-ET is a novel technique that appears to be safe and effective in achieving a curative resection for GI subepithelial tumors with a predominantly extraluminal growth pattern or extraluminal tumors in a selected group of patients. However, larger studies are required to validate our finding.

[Preferable surgery for benign tumors of the adrenal glands]

AIM

To determine optimal surgical approach in patients with adrenal tumors.

MATERIAL AND METHODS

Overall experience of treatment of patients with adrenal tumors comprises over 300 procedures including 152 minimally invasive surgeries.

RESULTS

We have presented the advantages and relative disadvantages of various technologies which are useful to be considered to determine the most optimal surgery in these patients.

CONCLUSION

There are no serious contradictions to use existing surgical methods in patients with adrenal tumors. Minimally invasive procedures along with conventional (open) interventions significantly enlarged rational choice in surgery for adrenal neoplasms and optimized personified approach.

Functional adrenal cortex preservation: A good reason for posterior retroperitoneal endoscopic approach

INTRODUCTION

Cortical-sparing adrenalectomy is a suitable treatment for hereditary and sporadic bilateral pheochromocytoma, in cases of low risk of malignancy, to reduce the possibility of adrenal insufficiency assuming the chance of local recurrence. The aim of the study is to analyze the functional results of partial adrenalectomy by retroperitoneal endoscopic approach in single-adrenal patients or patients requiring bilateral adrenalectomy.

METHODS

Prospective study between January 2015 and February 2016 including pheochromocytoma patients diagnosed with low risk of malignant mutations. All patients agreed to be included in the study. Experienced endocrine surgeons who have been trained in minimally invasive endocrine surgery performed the procedure using the same surgical technique. Demographic variables and clinical characteristics were collected, subsequently carrying out the descriptive analysis of the data.

RESULTS

A total of 6 patients were registered, four associated with MEN type 2 syndrome and two in the context of VHL syndrome. Retroperitoneoscopic resection was performed without laparoscopic or open conversion and no postoperative complications; the average hospital stay was 2.5 days. Preservation of the functional cortex without corticosteroids was achieved in 5 (83%) of out 6 cases with a follow-up of 26.2 ± 6 months. Today, these 5 patients have a preserved adrenal function without hormone replacement.

CONCLUSIONS

Cortical-sparing adrenalectomy by the retroperitoneal endoscopic approach, in expert hands, is safe and feasible for the treatment of hereditary and sporadic pheochromocytoma in a context of low malignancy, making it possible to avoid the need for corticoid replacement in most cases.

Extent of surgery for phaeochromocytomas in the genomic era

Background

Germline mutations are present in 20–30 per cent of patients with phaeochromocytoma. For patients who develop bilateral disease, complete removal of both adrenal glands (total adrenalectomy) will result in lifelong adrenal insufficiency with an increased risk of death from adrenal crisis. Unilateral/bilateral adrenal-sparing surgery (subtotal adrenalectomy) offers preservation of cortical function and independence from steroids, but leaves the adrenal medulla in situ and thus at risk of developing new and possibly malignant disease. Here, present knowledge about how tumour genotype relates to clinical behaviour is reviewed, and application of this knowledge when choosing the extent of adrenalectomy is discussed.

Methods

A literature review was undertaken of the penetrance of the different genotypes in phaeochromocytomas, the frequency of bilateral disease and malignancy, and the underlying pathophysiological mechanisms, with emphasis on explaining the clinical phenotypes of phaeochromocytomas and their associated syndromes.

Results

Patients with bilateral phaeochromocytomas most often have multiple endocrine neoplasia type 2 (MEN2) or von Hippel–Lindau disease (VHL) with high-penetrance mutations for benign disease, whereas patients with mutations in the genes encoding SDHB (succinate dehydrogenase subunit B) or MAX (myelocytomatosis viral proto-oncogene homologue-associated factor X) are at increased risk of malignancy.

Conclusion

Adrenal-sparing surgery should be the standard approach for patients who have already been diagnosed with MEN2 or VHL when operating on the first side, whereas complete removal of the affected adrenal gland(s) is generally recommended for patients with SDHB or MAX germline mutations. Routine assessment of a patient's genotype, even after the first operation, can be crucial for adopting an appropriate strategy for follow-up and future surgery.

Is there any role for minimally invasive surgery in NET?

Neuroendocrine tumors (NET) represent the variability of almost benign lesions either secreting hormones occurring as a single lesion up to malignant lesions with metastatic potential. Treatment of NET is usually performed by surgical resection. Due to the rarity of NET, surgical treatment is mainly based on the experience and recommendations of experts and less on the basis of prospective randomized studies. In addition, the development and establishment of new surgical procedures is made more difficult by their rarity. The development of laparoscopic-assisted surgery has significantly improved the treatment of many diseases. Due to the well-known advantages of laparoscopic surgery, this method has also been increasingly used to treat NET. However, due to limited comparative data, the assumed superiority of laparoscopic surgery in the area NET remains often unclear or not yet proven. This review focuses on the present usage of laparoscopic techniques in the area of NET. Relating to the current literature, this review presents the evidence of various laparoscopic procedures for treatment of adrenal, pancreatic and intestine NET as well as extraadrenal pheochromocytoma and neuroendocrine liver metastases. Further, this review focuses on recent new developments of minimally invasive surgery in the area of NET. Here, robotic-assisted surgery and single-port surgery are promising approaches.

Retroperitoneal paraganglioma-Is pre operative embolization useful?

INTRODUCTION

Paragangliomas (PG) are rare tumors derived from chromaffin cells that are located outside the adrenal gland and are capable of producing catecholamines. The treatment is based on a surgical resection, and there is controversy regarding the usefulness of previously carrying out an embolization and what is the most adequate surgical approach.

CLINICAL CASE

We will present a 17-year-old woman with a retroperitoneal tumour in contact with the aorta and the inferior vena cava, treated with embolization prior to the surgical resection via laparotomy.

DISCUSSION

The PG tumors are very infrequent and originate in the extra-adrenal chromaffin cells that exist in the vicinity of the components of the autonomic nervous system. Most of them (86%) produce catecholamines, are unique, sporadic, benign and more frequent in middle-aged women. Since they are radioresistant tumors, the only possibility for a cure is by a complete surgical excision. The preoperative embolization has been described mainly as the treatment of cervical PG, although its use in abdominal PG is more controversial and is not done in a systematic manner.

CONCLUSION

We can conclude that the embolization of abdominal PG is not free of risks and that it has not been demonstrated that it significantly reduces the peri-operative bleeding or the surgical time. Probably, the embolization should be reserved for intensively hypervascularized and larger PGs.