Minimally invasive cortical-sparing surgery for bilateral pheochromocytomas

Phaeochromocytoma and paraganglioma

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

[Personalized treatment of pheochromocytoma]

BACKGROUND

Pheochromocytoma is a rare but severe disease of the adrenal glands. The aim of this study is to present and discuss recent developments in the diagnosis and treatment of pheochromocytoma.

MATERIAL AND METHODS

A narrative review article based on the most recent literature is presented.

RESULTS AND DISCUSSION

The proportion of pheochromocytomas as tumors of adrenal origin is about 5% of incidentally discovered adrenal tumors. The classical symptomatic triad of headaches, sweating, and palpitations occurs in only about 20% of patients, while almost all patients show at least 1 of these symptoms. To diagnose pheochromocytoma, levels of free plasma metanephrines or alternatively, fractionated metanephrines in a 24‑h urine collection is required in a first step. In the second step an imaging procedure, computed tomography (CT) or magnetic resonance imaging (MRI), is performed to localize the adrenal tumor. Functional imaging is also recommended to preoperatively detect potential metastases. Genetic testing should always be offered during the course of treatment as 30-40% of pheochromocytomas are associated with genetic mutations. The dogma of preoperative alpha blockade is increasingly being questioned and has been controversially discussed in recent years. Minimally invasive removal of the adrenal tumor is the standard surgical procedure to cure patients with pheochromocytoma. The transabdominal and retroperitoneal laparoscopic approaches are considered equivalent. The choice of the minimally invasive procedure depends on the expertise and experience of the surgeon and should be tailored accordingly. Individualized and regular follow-up care is important after surgery.

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.

Phaeochromocytoma recurrence in a patient with multiple endocrine neoplasia type 2A

Multiple endocrine neoplasia type 2A (MEN2A) is a hereditary syndrome associated with tumours of the endocrine system. Principally, it is characterized by medullary thyroid carcinoma (MTC) with some individuals also developing phaeochromocytoma and hyperparathyroidism. Patients with fewer than two clinical features require either an identification of a germline rearranged in transfection mutation, or MEN2A characteristics in first-degree relatives, to establish a diagnosis of MEN2A. We present the case of a 54-year-old female with MEN2A, diagnosed by genetic screening, due to a substantial history of the disease in her ancestry. This case outlines the successful treatment of recurrent phaeochromocytoma, through the medium of radioactive iobenguane as an adjunct to surgical management. The report focuses particularly on the significance of innovative treatment strategies and forthcoming approaches to improve patient care in treating phaeochromocytoma in MEN2A.

Intraoperative imaging for remnant viability assessment in bilateral posterior retroperitoneoscopic partial adrenalectomy in an experimental model

BACKGROUND

A surgical approach preserving functional adrenal tissue allows biochemical cure while avoiding the need for lifelong steroid replacement. The aim of this experimental study was to evaluate the impact of intraoperative imaging during bilateral partial adrenalectomy on remnant perfusion and function.

METHODS

Five pigs underwent bilateral posterior retroperitoneoscopic central adrenal gland division (9 divided glands, 1 undivided). Intraoperative perfusion assessment included computer-assisted quantitative fluorescence imaging, contrast-enhanced CT, confocal laser endomicroscopy (CLE) and local lactate sampling. Specimen analysis after completion adrenalectomy (10 adrenal glands) comprised mitochondrial activity and electron microscopy.

RESULTS

Fluorescence signal intensity evolution over time was significantly lower in the cranial segment of each adrenal gland (mean(s.d.) 0·052(0·057) versus 0·133(0·057) change in intensity per s for cranial versus caudal parts respectively; P = 0·020). Concordantly, intraoperative CT in the portal phase demonstrated significantly lower contrast uptake in cranial segments (P = 0·031). In CLE, fluorescein contrast was observed in all caudal segments, but in only four of nine cranial segments (P = 0·035). Imaging findings favouring caudal perfusion were congruent, with significantly lower local capillary lactate levels caudally (mean(s.d.) 5·66(5·79) versus 11·58(6·53) mmol/l for caudal versus cranial parts respectively; P = 0·008). Electron microscopy showed more necrotic cells cranially (P = 0·031). There was no disparity in mitochondrial activity (respiratory rates, reactive oxygen species and hydrogen peroxide production) between the different segments.

CONCLUSION

In a model of bilateral partial adrenalectomy, three intraoperative imaging modalities consistently discriminated between regular and reduced adrenal remnant perfusion. By avoiding circumferential dissection, mitochondrial function was preserved in each segment of the adrenal glands. Surgical relevance Preservation of adrenal tissue to maintain postoperative function is essential in bilateral and hereditary adrenal pathologies. There is interindividual variation in residual adrenocortical stress capacity, and the minimal functional remnant size is unknown. New intraoperative imaging technologies allow improved remnant size and perfusion assessment. Fluorescence imaging and contrast-enhanced intraoperative CT showed congruent results in evaluation of perfusion. Intraoperative imaging can help to visualize the remnant vascular supply in partial adrenalectomy. Intraoperative assessment of perfusion may foster maximal functional tissue preservation in bilateral adrenal pathologies and procedures.

Adrenal-sparing surgery: current concepts on a theme from the past

Adrenal insufficiency represents a debilitating condition which mandates lifelong steroid replacement and which is associated with significant long-term morbidity, due to either inadequate or excessive replacement. The concept of preserving healthy cortical tissue by means of partial adrenalectomy has evolved as a means of avoiding the detrimental consequences of adrenal insufficiency. The advent of advanced technology in adrenal surgery has greatly facilitated the performance of partial adrenalectomy, enabling utilization of this method in an increasing number of endocrine diseases. Hereditary pheochromocytoma, Conn's syndrome, Cushing's syndrome, and non-functional adrenal masses represent the current indications for partial adrenalectomy, although the specific circumstances under which adrenal-sparing surgery should be proposed are still debatable. Partial adrenalectomy can be achieved by all types of minimally invasive surgery. In the absence of randomized, prospective, controlled studies designed to compare laparoscopic, retroperitoneoscopic, and robot-assisted partial adrenalectomy, none of these techniques has as yet been proven to be the gold standard for adrenal-sparing surgery. Apart from indications for surgery, results of surgery, and different types of partial adrenalectomy, controversial topics addressed in this review article include technical aspects such as the volume of residual adrenal tissue needed, ligation of adrenal vein, and means of tumor identification. Discussion of these controversial topics represents an attempt to define the role of partial adrenalectomy in modern adrenal surgery.

Indocyanine green fluorescence imaging for robotic adrenalectomy

Despite the novel and innovative developments in minimal invasive platforms and the expanding indications regarding adrenal surgery, surgeons are still confronted with some obstacles. The use of intraoperative indocyanine green aims to overcome these problems, but there is still limited data and ongoing debates in terms of robot-assisted adrenal surgery. The aim of this article is to discuss the benefit of indocyanine green fluorescence imaging for robot-assisted adrenalectomy and provide up-to date data.

[Surgery of adrenal diseases]

Incidentally discovered adrenal alterations should be separated into those without any clinical importance and adrenal diseases that have to be surgically or conservatively treated. Before operative treatment, in addition to the possible different functional activity of tumors, a differentiation must be made between sporadically arising singular or multiple adrenal tumors or nodular adrenal hyperplasia, adrenal tumors as part of a familial syndrome and metastases of other primary malignant tumors into the adrenal glands. Benign hormonally active adrenal tumors as well as questionable malignant tumors of the adrenal cortex are resected by minimally invasive techniques. For large malignant tumors infiltrating into surrounding tissues and tumors with proven lymph node metastases, the primarily open approach is indicated. Patients with adrenal diseases should always undergo an interdisciplinary assessment and in cases with clear indications for surgery, sometimes transferred to a center with experience in surgery and postoperative management of these patients.

Large Adrenal Lesion Series in a Tertiary Care Center in Northern India: Diagnostic and Operative Challenges

Large adrenal tumors pose varied challenges to surgeons in terms of diagnosis, planning surgical approach, and also intra-operative difficulties in resection. The aim of this study is to discuss challenges in the management of large and difficult adrenal lesions. A retrospective analysis was done on data of all patients with large adrenal lesions/paragangliomas managed from 1 June 2016 to 30 August 2018. Forty-eight patients with adrenal lesions underwent treatment in 2 years duration. Pain in the abdomen was the most common presentation. Mean age was 34.4 years (range 2-60), female to male (23:25) and right to left side to bilateral tumor 30:16:2. Thirty-one (64.6%) patients had large adrenal masses (size > 6 cm). Surgical approaches included open transperitoneal adrenalectomy (n = 20) and laparoscopic transperitoneal (n = 9 and 2 others had conversion to open procedure). Challenges faced are described in the table below: [Table: see text] There were no major peri-operative morbidities, but two patients died in perioperative period. Large adrenal tumors pose a challenge in surgical planning, approach, and resection and need careful planning and multidisciplinary team approach to have the best outcomes.

Evaluation and management of adrenal neoplasms: endocrinologist and endocrine surgeon perspectives

The evaluation and management of adrenal disease is a complex endeavor that relies on an expert knowledge of human physiology and anatomy. Careful and proper patient assessment mandates a balanced approach which marries the disciplines of endocrinology, surgery, and radiology. Any of these three specialties may be on the front line in performing the initial workup when an adrenal neoplasm is discovered. With an ever-increasing volume of cross-sectional imaging, be it CT, MRI, or PET, large numbers of adrenal incidentalomas are being discovered. A close collaboration amongst specialties should strive to streamline the initial evaluation and minimize unnecessary testing and treatment.

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.

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.

Fluorescence-enabled assessment of adrenal gland localization and perfusion in posterior retroperitoneoscopic adrenal surgery in a preclinical model

BACKGROUND

The posterior retroperitoneoscopic adrenal access represents a challenge in orientation and working space creation. The aim of this experimental acute study was to evaluate the impact of computer-assisted quantitative fluorescence imaging on adrenal gland identification and assessment of intraoperative remnant perfusion for adrenal resection in the posterior retroperitoneoscopic approach.

METHODS

Six pigs underwent simultaneous (n = 5) or sequential (n = 1) bilateral posterior retroperitoneoscopic adrenalectomy (n = 12). Fluorescence imaging was obtained via intravenous administration of 3 mL of Indocyanine Green (ICG) and by switching the camera systems to near-infrared mode (D-LIGHT P, KARL STORZ; Germany). Fluorescence-based visualization of adrenal glands before vascular division (n = 4), after the main vascular pedicle ligation (negative control, n = 1) or after adrenal resection (n = 7), was followed by completion adrenalectomy. The fluorescence signal intensity dynamics were recorded and analyzed using proprietary software. For each pixel, the slope of fluorescence signal intensity evolution over time was translated into a color-coded perfusion cartography, which was superimposed onto real-time images obtained with the corresponding left and right camera systems. Quantitative fluorescence signal analysis in the regions of interest (ROIs) served to assess adrenal remnant perfusion in divided adrenal glands.

RESULTS

In the retroperitoneum, the vascular anatomy was illuminated in fluorescence imaging first. The adrenal glands were promptly highlighted after primary intravenous ICG administration (n = 9) or showed a fluorescence signal intensity increase upon reinjection (n = 3). Quantitative fluorescence analysis showed a statistically significant difference between perfused and ischemic segments in divided glands (p = 0.0156).

CONCLUSIONS

Fluorescence imaging provides real-time guidance during minimally invasive adrenal surgery. Prior to dissection, it allows to easily discriminate the adrenal gland from surrounding retroperitoneal structures. After adrenal gland division, ICG injection associated with a computer-assisted quantitative analysis helps to distinguish between well-perfused and ischemic segments. Further studies are underway to establish the correlation between remnant perfusion and viability.

Precision Surgery for Pheochromocytomas and Paragangliomas

Since Felix Fränkel's account of pheochromocytoma in 1886, great discoveries and vast advancements in the diagnosis, genetics, anatomical and functional imaging techniques, and surgical management of pheochromcytoma and paraganglioma (P-PGL) have been made. The improved insight in the pathophysiology of P-PGL and more accurate detection methods enable physicians to tailor the treatment plan to an individual based on the genetic profile and tumor behavior. This review will cover briefly the clinical features, diagnosis, genetic mutations, and imaging modalities that are used to guide current surgical management of these rare and interesting endocrinopathies.

Challenges of training in adrenal surgery

While adrenal tumors are common, adrenalectomy is rather uncommon. This is one reason for the many challenges regarding the training of adrenal surgery. Here we focus on issues that are most pertinent regarding training of the young surgeons performing adrenalectomy. Due to the very limited literature, what is presented is mainly based on personal experience and/or from the literature published for other surgical operations and subspecialties. The discussed challenges include indications for surgery, surgical approaches and extent, and intraoperative complications. With advances in adrenal surgery, we expect some old challenges to be resolved, and some new challenges to arise. These challenges will be faced in order to continue to help our younger trainee acquire the knowledge and skills to best care for our patients with adrenal diseases.

Surgical therapy of adrenal tumors: guidelines from the German Association of Endocrine Surgeons (CAEK)

BACKGROUND AND AIMS

Previous guidelines addressing surgery of adrenal tumors required actualization in adaption of developments in the area. The present guideline aims to provide practical and qualified recommendations on an evidence-based level reviewing the prevalent literature for the surgical therapy of adrenal tumors referring to patients of all age groups in operative medicine who require adrenal surgery. It primarily addresses general and visceral surgeons but offers information for all medical doctors related to conservative, ambulatory or inpatient care, rehabilitation, and general practice as well as pediatrics. It extends to interested patients to improve the knowledge and participation in the decision-making process regarding indications and methods of management of adrenal tumors. Furthermore, it provides effective medical options for the surgical treatment of adrenal lesions and balances positive and negative effects. Specific clinical questions addressed refer to indication, diagnostic procedures, effective therapeutic alternatives to surgery, type and extent of surgery, and postoperative management and follow-up regime.

METHODS

A PubMed research using specific key words identified literature to be considered and was evaluated for evidence previous to a formal Delphi decision process that finalized consented recommendations in a multidisciplinary setting.

RESULTS

Overall, 12 general and 52 specific recommendations regarding surgery for adrenal tumors were generated and complementary comments provided.

CONCLUSION

Effective and balanced medical options for the surgical treatment of adrenal tumors are provided on evidence-base. Specific clinical questions regarding indication, diagnostic procedures, alternatives to and type as well as extent of surgery for adrenal tumors including postoperative management are addressed.

La chirurgie d’épargne surrénalienne : du cortex à la médulla

The 2017 Endocrine Society annual meeting included several communications and debates on the conservative adrenal surgery in bilateral hereditary pheochromocytomas (BHP), bilateral adrenal macronodular hyperplasia (BAMH) and primary hyperaldosteronism (PHA). The general principle is to preserve a part of the adrenal cortex to prevent the occurrence of a definitive adrenal insufficiency. In BHP, cortical sparing surgery allows more than 50% of patients to maintain normal corticotropic function at 10 years with a low recurrence rate (~ 10%). Since the adrenal medulla cannot be removed entirely, recurrence seems inevitable and long-term follow-up is essential. Individual risk of malignancy must be taken into account. In BAMH responsible for Cushing syndrome, unilateral adrenalectomy induces a normalization of urinary free cortisol in 92 to 100% of cases and even corticotropic insufficiency in 40 to 100% of cases. This is most often transient. Late recurrences of Cushing's syndrome may occur in 13 to 60% of cases. Prolonged patient monitoring is therefore essential. In PAH with lateralized aldosterone production, minimally invasive partial adrenal surgery, which consists of removing only the adrenal adenoma visualized at TDM, allows an improvement blood pressure in about 94% of patients. However, failure or recurrence may occur. Its place therefore remains marginal in the treatment of the lateralized PAHs.

Posterior retroperitoneoscopic thoracic duct ligation: a novel surgical approach

BACKGROUND

Treatment of postoperative chylothorax can be challenging. Conservative treatment and/or surgical management by means of open or minimally invasive thoracic duct ligation for persistent chylothorax are accepted therapeutic options. We present a new retroperitoneoscopic approach for thoracic duct ligation.

METHODS

Between January 2006 and May 2017, posterior retroperitoneoscopic thoracic duct ligation was performed in four patients. The thoracic duct was identified transdiaphragmatically and ligated cranially to the cisterna chyli using absorbable clips.

RESULTS

Retroperitoneoscopic ligation resulted in a complete and lasting chylothorax resolution in three patients and marked improvement in a fourth one. Mean operative time was 86 min (range 40-135). There were no perioperative or postoperative complications.

CONCLUSIONS

Retroperitoneoscopic thoracic duct ligation is feasible and safe. It allows for a precise anatomical exploration of the thoracic duct caudally to the chyle leak, avoiding the previous operative field and resulting in minimal morbidity. In patients with persistent chylothorax, our approach provides an additional therapeutic option.

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.

Surgical approaches in hereditary endocrine tumors

Endocrine tumors of thyroid, adrenal and parathyroid glands may be due to germline and inheritable mutations in 5-30% of patients. Medullary Thyroid Carcinoma, Pheochromocytoma, Paraganglioma, and Familial Primary Hyperparathyroidism are the most frequent entity. Hereditary endocrine tumors usually have a suggestive familial history; they occur earlier than sporadic variants, are multifocal, and have increased recurrence rates. They may be present as isolated variant or associated to other neoplasms in a syndromic setting. Genetic diagnosis should be preferably available before surgery because specific and targeted operative management are needed to achieve the best chance of cure. This review was aimed to discuss the surgical approaches for some of the most frequent hereditary endocrine tumors of thyroid, adrenal and parathyroid glands, focusing on medullary thyroid carcinoma, Pheochromocytoma, Paraganglioma and hereditary primary hyperparathyroidism (pHPT). Hereditary Medullary Thyroid Carcinoma is caused by RET mutations, and may be associated to Pheochromocytomas in MEN 2 setting. Total thyroidectomy and at least central neck nodal dissection is required. The availability of genetic screening allows prophylactic or early surgery in asymptomatic patients, with subsequent definitive cure. Hereditary Pheochromocytomas may be present in several syndromes (MEN 2, VHL, NF1, Paraganglioma/Pheochromocytoma syndrome); it may involve both adrenals; in these cases, a cortical sparing adrenalectomy should be performed to avoid permanent hypocorticosurrenalism. Hereditary Primary Hyperparathyroidism may frequently occur associated to MEN 1, MEN 2A, MEN 4, Hyperparathyroidism-Jaw Tumor Syndrome; it may involve all the parathyroid glands, requiring subtotal parathyroidectomy or total parathyroidectomy plus autotransplantation. In some cases, a selective parathyroidectomy might be performed.

Paraganglioma and phaeochromocytoma: from genetics to personalized medicine

Paragangliomas and phaeochromocytomas are neuroendocrine tumours whose pathogenesis and progression are very strongly influenced by genetics. A germline mutation in one of the susceptibility genes identified so far explains ∼40% of all cases; the remaining 60% are thought to be sporadic cases. At least one-third of these sporadic tumours contain a somatic mutation in a predisposing gene. Genetic testing, which is indicated in every patient, is guided by the clinical presentation as well as by the secretory phenotype and the immunohistochemical characterization of the tumours. The diagnosis of an inherited form drives clinical management and tumour surveillance. Different 'omics' profiling methods have provided a neat classification of these tumours in accordance with their genetic background. Transcriptomic studies have identified two main molecular pathways that underlie development of these tumours, one in which the hypoxic pathway is activated (cluster 1) and another in which the MAPK and mTOR (mammalian target of rapamycin) signalling pathways are activated (cluster 2). DNA methylation profiling has uncovered a hypermethylator phenotype in tumours related to SDHx genes (a group of genes comprising SDHA, SDHB, SDHC, SDHD and SDHAF2) and revealed that succinate acts as an oncometabolite, inhibiting 2-oxoglutarate-dependent dioxygenases, such as hypoxia-inducible factor prolyl-hydroxylases and histone and DNA demethylases. 'Omics' data have suggested new therapeutic targets for patients with a malignant tumour. In the near future, new 'omics'-based tests are likely to be transferred into clinical practice with the goal of establishing personalized medical management for affected patients.

Diagnosis and preoperative imaging of multiple endocrine neoplasia type 2: current status and future directions

Multiple endocrine neoplasia type 2 (MEN2) is a rare autosomal dominant syndrome caused by mutations in the RET protooncogene and is characterized by a strong penetrance of medullary thyroid carcinoma (all subtypes) and is often accompanied by pheochromocytoma (MEN2A/2B) and primary hyperparathyroidism (MEN2A). The evaluation and management of MEN2-related tumours is often different from that of sporadic counterparts. This review article provides an overview of clinical manifestations, diagnosis and surgical management of MEN2 patients. This review also presents applications of the most up-to-date imaging modalities to MEN2 patients that are tightly linked to the clinical management and aims to guide physicians towards a rationale for the use of imaging prior to prophylactic thyroidectomy, initial surgery and reoperations for persistent/recurrent disease. This review also concludes that, in the near future, it is expected that these patients will indeed benefit from newly developed positron emission tomography approaches which will target peptide receptors and protein kinases. Identification of MEN2-specific radiopharmaceuticals will also soon arise from molecular profiling studies. Furthermore, subtotal (cortical-sparing) adrenalectomy, which is a valid option in MEN2 for avoiding long-term steroid replacement, will benefit from an accurate estimation through imaging of differential adrenocortical function.

Pheochromocytoma and paraganglioma: an endocrine society clinical practice guideline

OBJECTIVE

The aim was to formulate clinical practice guidelines for pheochromocytoma and paraganglioma (PPGL).

PARTICIPANTS

The Task Force included a chair selected by the Endocrine Society Clinical Guidelines Subcommittee (CGS), seven experts in the field, and a methodologist. The authors received no corporate funding or remuneration.

EVIDENCE

This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system to describe both the strength of recommendations and the quality of evidence. The Task Force reviewed primary evidence and commissioned two additional systematic reviews.

CONSENSUS PROCESS

One group meeting, several conference calls, and e-mail communications enabled consensus. Committees and members of the Endocrine Society, European Society of Endocrinology, and Americal Association for Clinical Chemistry reviewed drafts of the guidelines.

CONCLUSIONS

The Task Force recommends that initial biochemical testing for PPGLs should include measurements of plasma free or urinary fractionated metanephrines. Consideration should be given to preanalytical factors leading to false-positive or false-negative results. All positive results require follow-up. Computed tomography is suggested for initial imaging, but magnetic resonance is a better option in patients with metastatic disease or when radiation exposure must be limited. (123)I-metaiodobenzylguanidine scintigraphy is a useful imaging modality for metastatic PPGLs. We recommend consideration of genetic testing in all patients, with testing by accredited laboratories. Patients with paraganglioma should be tested for SDHx mutations, and those with metastatic disease for SDHB mutations. All patients with functional PPGLs should undergo preoperative blockade to prevent perioperative complications. Preparation should include a high-sodium diet and fluid intake to prevent postoperative hypotension. We recommend minimally invasive adrenalectomy for most pheochromocytomas with open resection for most paragangliomas. Partial adrenalectomy is an option for selected patients. Lifelong follow-up is suggested to detect recurrent or metastatic disease. We suggest personalized management with evaluation and treatment by multidisciplinary teams with appropriate expertise to ensure favorable outcomes.

Surgical management of adrenocortical tumours

The surgical treatment of adrenal tumours has evolved over the past century, as has our understanding of which hormones are secreted by the adrenal glands and what these hormones do. This article reviews the preoperative evaluation of patients with adrenal tumours that could be benign or malignant, including metastases. The biochemical evaluation of excess levels of hormones is discussed, as are imaging characteristics that differentiate benign tumours from malignant tumours. The options for surgical management are outlined, including the advantages and disadvantages of various open and laparoscopic approaches. The surgical management of adrenocortical carcinoma is specifically reviewed, including controversies in operative approaches as well as surgical management of invasive or recurrent disease.

Outcomes of adrenal-sparing surgery or total adrenalectomy in phaeochromocytoma associated with multiple endocrine neoplasia type 2: an international retrospective population-based study

BACKGROUND

The prevention of medullary thyroid cancer in patients with multiple endocrine neoplasia type 2 syndrome has demonstrated the ability of molecular diagnosis and prophylactic surgery to improve patient outcomes. However, the other major neoplasia associated with multiple endocrine neoplasia type 2, phaeochromocytoma, is not as well characterised in terms of occurrence and treatment outcomes. In this study, we aimed to systematically characterise the outcomes of management of phaeochromocytoma associated with multiple endocrine neoplasia type 2.

METHODS

This multinational observational retrospective population-based study compiled data on patients with multiple endocrine neoplasia type 2 from 30 academic medical centres across Europe, the Americas, and Asia. Patients were included if they were carriers of germline pathogenic mutations of the RET gene, or were first-degree relatives with histologically proven medullary thyroid cancer and phaeochromocytoma. We gathered clinical information about patients'RET genotype, type of treatment for phaeochromocytoma (ie, unilateral or bilateral operations as adrenalectomy or adrenal-sparing surgery, and as open or endoscopic operations), and postoperative outcomes (adrenal function, malignancy, and death). The type of surgery was decided by each investigator and the timing of surgery was patient driven. The primary aim of our analysis was to compare disease-free survival after either adrenal-sparing surgery or adrenalectomy.

FINDINGS

1210 patients with multiple endocrine neoplasia type 2 were included in our database, 563 of whom had phaeochromocytoma. Treatment was adrenalectomy in 438 (79%) of 552 operated patients, and adrenal-sparing surgery in 114 (21%). Phaeochromocytoma recurrence occurred in four (3%) of 153 of the operated glands after adrenal-sparing surgery after 6-13 years, compared with 11 (2%) of 717 glands operated by adrenalectomy (p=0.57). Postoperative adrenal insufficiency or steroid dependency developed in 292 (86%) of 339 patients with bilateral phaeochromocytoma who underwent surgery. However, 47 (57%) of 82 patients with bilateral phaeochromocytoma who underwent adrenal-sparing surgery did not become steroid dependent.

INTERPRETATION

The treatment of multiple endocrine neoplasia type 2-related phaeochromocytoma continues to rely on adrenalectomies with their associated Addisonian-like complications and consequent lifelong dependency on steroids. Adrenal-sparing surgery, a highly successful treatment option in experienced centres, should be the surgical approach of choice to reduce these complications.

Multiplicity of hormone-secreting tumors: common themes about cause, expression, and management

CONTEXT

Multiplicity of hormone-secreting tumors occurs in a substantial portion of hormone-excess states. Multiplicity increases the difficulty of management and drives the selection of special strategies.

EVIDENCE ACQUISITION

This is a synthesis from publications about tumor development and expression, and also about types of clinical strategy for hormone-secreting tumors.

EVIDENCE SYNTHESIS

Comparisons were made between patient groups with solitary tumors vs those with multiple tumors. Major themes with clinical relevance emerged. Usually, tumor multiplicity develops from a genetic susceptibility in all cells of a tissue. This applies to hormone-secreting tumors that begin as either polyclonal (such as in the parathyroids of familial hypocalciuric hypercalcemia) or monoclonal tumors (such as in the parathyroids of multiple endocrine neoplasia type 1 [MEN1]). High penetrance of a hereditary tumor frequently results in bilaterality and in several other types of multiplicity. Managements are better for the hormone excess than for the associated cancers. Management strategies can be categorized broadly as ablation that is total, subtotal, or zero. Examples are discussed for each category, and 1 example of each category is named here: 1) total ablation of the entire tissue with effort to replace ablated functions (for example, in C-cell neoplasia of multiple endocrine neoplasia type 2); 2) subtotal ablation with increased likelihood of persistent disease or recurrent disease (for example, in the parathyroid tumors of MEN1); or 3) no ablation of tissue with or without the use of pharmacotherapy (for example, with blockers for secretion of stomach acid in gastrinomas of MEN1).

CONCLUSIONS

Tumor multiplicity usually arises from defects in all cells of the precursor tissue. Even the optimized managements involve compromises. Still, an understanding of pathophysiology and of therapeutic options should guide optimized management.

Robotic partial adrenalectomy using indocyanine green dye with near-infrared imaging: the initial clinical experience

OBJECTIVE

To present the initial clinical experience with robot-assisted partial adrenalectomy using indocyanine green dye with near-infrared fluorescence (ICG-NIRF) imaging.

METHODS

Three consecutive patients with solitary adrenal masses with worrisome features were referred for treatment. The preoperative workup included dedicated axial imaging and adrenal function studies. All patients underwent purely robotic partial adrenalectomy with ICG-NIRF guidance. Relevant steps of the technique included a transperitoneal approach, gross identification of the adrenal gland, administration of 5 mg intravenous ICG, and finally, mass resection guided by ICG-NIRF and white light visualization in an effort to completely excise the mass while sparing uninvolved adrenal tissue.

RESULTS

Robotic partial adrenalectomy was successfully performed with negative margins in all patients. All masses were hypofluorescent relative to normal adrenal tissue with ICG-NIRF and included a pheochromocytoma, lipoadenoma, and follicular lymphoid hyperplasia.

CONCLUSION

Robotic partial adrenalectomy with intraoperative ICG-NIRF is safe and feasible. The addition of ICG-NIRF may help mass identification, excision, and promote the use adrenal-sparing surgery.

Molecular and therapeutic advances in the diagnosis and management of malignant pheochromocytomas and paragangliomas

Pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare catecholamine-secreting tumors derived from chromaffin cells originating in the neural crest. These tumors represent a significant diagnostic and therapeutic challenge because the diagnosis of malignancy is frequently made in retrospect by the development of metastatic or recurrent disease. Complete surgical resection offers the only potential for cure; however, recurrence can occur even after apparently successful resection of the primary tumor. The prognosis for malignant disease is poor because traditional treatment modalities have been limited. The last decade has witnessed exciting discoveries in the study of PCCs and PGLs; advances in molecular genetics have uncovered hereditary and germline mutations of at least 10 genes that contribute to the development of these tumors, and increasing knowledge of genotype-phenotype interactions has facilitated more accurate determination of malignant potential. Elucidating the molecular mechanisms responsible for malignant transformation in these tumors has opened avenues of investigation into targeted therapeutics that show promising results. There have also been significant advances in functional and radiological imaging and in the surgical approach to adrenalectomy, which remains the mainstay of treatment for PCC. In this review, we discuss the currently available diagnostic and therapeutic options for patients with malignant PCCs and PGLs and detail the molecular rationale and clinical evidence for novel and emerging diagnostic and therapeutic strategies.

Long-term outcomes of surgical treatment for hereditary pheochromocytoma

BACKGROUND

The ideal surgical management of hereditary pheochromocytomas includes planning for a potential metachronous bilateral presentation and the possibility of lifelong steroid dependence if bilateral adrenalectomy is needed. An intact and viable cortical remnant after bilateral pheochromocytoma resection can eliminate the necessity for steroid dependency, but can increase the risk of pheochromocytoma recurrence.

STUDY DESIGN

We retrospectively reviewed outcomes of all patients with a diagnosis of hereditary pheochromocytomas treated at our tertiary cancer institution from 1962-2011, with subset analysis of patients undergoing a cortical-sparing procedure in the setting of bilateral adrenalectomy.

RESULTS

Of the ninety-six patients who underwent adrenalectomy for hereditary pheochromocytomas, 47 presented with bilateral disease. In 15 of the 49 patients (30%) who originally underwent unilateral adrenalectomy, pheochromocytoma developed in the contralateral gland at a median of 8.2 years (range 1 to 20 years) after the initial diagnosis. There were 4 recurrences in 55 cortical-sparing remnants (7%) and 3 recurrences in the adrenal bed after 101 intended total adrenal resections (3%) (p = 0.24). Total bilateral adrenalectomy was performed in 25 patients and acute adrenal insufficiency developed in 5 (20%) of those patients. An intended cortical-sparing adrenalectomy was performed in 39 patients and acute adrenal insufficiency developed in 1 (3%). Of these patients with adequate follow-up, 21 of 27 (78%) were steroid independent at 3-year follow-up. Sex, median age, adrenal vein preservation, metachronous adrenal resection, and bilateral cortical-sparing procedures did not predict steroid independence at 3 years.

CONCLUSIONS

Cortical-sparing adrenalectomy avoids long-term corticosteroid dependence in the majority of patients with hereditary pheochromocytoma with minimal risk of acute adrenal insufficiency. Recurrence occurs in approximately 7% of adrenal remnants.

[Function-preserving adrenalectomy for adrenal tumors]

Organ preserving resection (subtotal adrenalectomy) or adrenocortical autotransplantation can preserve adrenocortical stress capacity in bilateral adrenal surgery. After adrenocortical autotransplantation approximately 30% of patients do not need exogenous steroids. Organ preserving surgery avoids steroid supplementation in more than 80% of cases. After organ preserving resections in secondary or familial diseases, however, there is a relevant risk of recurrent disease: the rate of ipsilateral recurrence in familial pheochromocytoma is approximately 20% during a follow-up of 20 years. Routine administration of exogenous steroids should be avoided after subtotal adrenalectomy as functional restitution of the residual tissue might be disturbed. Approximately 80% of patients, however, present with impaired adrenocortical stress capacity directly after surgery. Within a few weeks some 80% of patients show a sufficient functional restitution of the adrenocortical stress capacity. Organ preserving adrenal surgery should be performed endoscopically. The adrenal remnant should not be devascularized; the adrenal vein, however, can be divided without functional consequences. About one third of a normal adrenal gland usually provides sufficient adrenocortical function.