Surgical management of hereditary pheochromocytoma1 1No competing interests declared

Clinical Significance of Pheochromocytoma Size on the Timing and Extent of Surgery

INTRODUCTION

Elevated metanephrine and catecholamine levels 3-fold upper limit of normal (ULN) are diagnostic for pheochromocytoma. We sought to determine whether size correlates with biochemical activity or symptoms which could guide timing of surgery.

METHODS

Data from consecutive patients undergoing adrenalectomy for pheochromocytoma at our institution over a 10-year period were retrospectively collected. These included maximal lesion diameter on preoperative imaging, plasma/urine metanephrine and/or catecholamine levels, demographic variables and presence of typical paroxysmal symptoms. Receiver operating characteristic curves were used to assess predictive accuracy.

RESULTS

Sixty-three patients were included in the analysis (41 females and 22 males). Median age was 56 (43, 69) years. Due to various referring practices, 31 patients had documented 24-h urine metanephrine, 26 had 24-h urine catecholamine, and 52 had fractionated plasma metanephrine levels available for review. Values were converted to fold change compared to ULN and the maximum of all measured values was used for logistic regression. Median tumor size was 3.40 (2.25, 4.55) cm in greatest dimension. Tumor size at which pheochromocytoma produced > 3-fold ULN was ≥2.3 cm (AUC of 0.84). Biochemical activity increased with doubling tumor size (odds ratio = 8, P = 0.0004) or ≥ 1 cm increase in tumor size (odds ratio = 3.03, P = 0.001). 40 patients had paroxysmal symptoms, but there was no significant correlation between tumor size/biochemical activity and symptoms.

CONCLUSIONS

In our study, tumor size directly correlated with the degree of biochemical activity and pheochromocytomas ≥2.3 cm produced levels 3 times ULN. These findings may allow clinicians to adjust timing of operative intervention.

Succinate Dehydrogenase Mutations as Familial Pheochromocytoma Syndromes

It is recognized that a large portion of pheochromocytoma and paraganglioma cases will have an underlying germline mutation, supporting the recommendation for universal genetic testing in all patients with PPGLs. A mutation in succinate dehydrogenase subunit B is associated with increased rates of developing synchronous and/or metachronous metastatic disease. Patients identified with this mutation require meticulous preoperative evaluation, a personalized surgical plan to minimize the risk of recurrence and tumor spread, and lifelong surveillance.

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.

Recurrent ipsilateral pheochromocytoma in carriers of RET p.Cys634 missense mutations

PURPOSE

The objective of this study was to provide RET genotype-specific data on recurrent ipsilateral pheochromocytoma in multiple endocrine neoplasia type 2A (MEN2A), which are sparse.

METHODS

Kaplan-Meier analyses were performed to determine the risk of recurrent ipsilateral adrenalectomy after subtotal and total adrenalectomy in 221 carriers of RET p.Cys634 missense mutations.

RESULTS

Altogether, pheochromocytoma emerged in 112 of 442 adrenals at risk, for which 63 adrenals underwent total adrenalectomy and 49 adrenals subtotal adrenalectomy. After a mean (median) of 99 (132.9) months, 10 recurrent ipsilateral pheochromocytomas arose in 10 (20.4%) of 49 adrenal remnants. Seven of these 10 adrenal remnants were subjected to total adrenalectomy and 3 to another subtotal adrenalectomy. After 23 and 250 (mean/median 136.5) more months, 2 of the 3 remaining adrenal remnants gave rise to 2 further recurrent ipsilateral pheochromocytomas, which were removed by total adrenalectomy. When the rare publications in which carriers of RET p.Cys634 mutations made up 81-84% of MEN2A patients were combined with the present RET p.Cys634-specific series, the risk of recurrent ipsilateral pheochromocytoma was 6.7% (25 recurrent ipsilateral pheochromocytomas in 375 adrenal remnants), with a mean time interval of 146 months after initial subtotal adrenalectomy.

CONCLUSION

Subtotal adrenalectomy is a viable treatment option for many carriers of RET p.Cys634 mutations who develop an initial pheochromocytoma. Although the adrenal remnant may give rise to recurrent ipsilateral pheochromocytoma after 8-11 years in up to 20% of patients, it is manageable very well in experienced hands, buying the patient valuable time off steroids.

Association between pheochromocytoma and neurofibromatosis type I: a rare entity in the African population

The association of pheochromocytoma in patients with neurofibromatosis type I has rarely been reported in low-income countries, especially on the African continent. A 43-year-old woman with neurofibromatosis type I was diagnosed with a right adrenal pheochromocytoma in Pretoria, South Africa. To our knowledge, this report is the first case to be published of a patient with neurofibromatosis type I diagnosed with a pheochromocytoma in Pretoria, and one of three cases on the African continent. The rarity may be due to the two associated conditions being under-reported, undiagnosed, misdiagnosed or possibly the association is rare on the African continent. The clinician dealing with these two conditions should be aware of the association.

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.

Pediatric pheochromocytoma: current status of diagnostic imaging and treatment procedures

PURPOSE OF REVIEW

To provide an overview of relevant data available and updated recommendations for management of pediatric patients with pheochromocytoma (PCC).

RECENT FINDINGS

Much of the available data surrounding pediatric PCC is in the form of case reports and case series. With the accumulation of data over time, pediatric PCC does in fact differ significantly from not only what is known in the adult population, but also from classic teaching. Pediatric patients are much more likely to have a hereditary predisposition as well as aggressive and malignant disease. Much of the recent literature focuses on defining these genetic syndromes in order to provide recommendations for screening and genetic counseling. Other recent advances center around developing treatments for metastatic disease. Timely diagnosis with plasma metanephrines and cross-sectional imaging, and appropriate preoperative medical optimization followed by surgical resection remain the center of treatment.

SUMMARY

Although rare and adult principles are applied to pediatric PCC, genetic testing plays a pivotal role in management of children, adolescents and young adults with PCC.

100-Year evolution of precision medicine and surgery for multiple endocrine neoplasia type 2A

PURPOSE

To determine whether published disease penetrance estimates of 50% for pheochromocytoma and 20-30% for primary hyperparathyroidism in multiple endocrine neoplasia (MEN 2A), conceivably reflecting overrepresentation of index patients with completely developed MEN 2A, may be too high.

METHODS

Cross-sectional study of carriers at high risk of MEN 2A from a tertiary referral center.

RESULTS

There were 213 carriers of RET mutations in codon 634, born between 1922 and 2014. Median age of thyroidectomy was 17 years, with MTC being present in 76.5%; pheochromocytoma in 31.0% at a median of 34 years in the first, and in 18.8% at a median of 35 years in the second adrenal; and primary hyperparathyroidism in 10.8% at a median of 39 years. MTC, pheochromocytoma and primary hyperparathyroidism, stratified by year of birth, were diagnosed earlier over time: for MTC from 51 to 4 years; for pheochromocytoma from 51 to 22.5 years in the first, and from 51 to 29.5 years in the second adrenal, and for primary hyperparathyroidism from 46 to 12 years (P ≤ 0.008). This decline in age was paralleled by diminishing tumor diameters, more strongly in the thyroid (from 20 to 1.8 mm; P < 0.001) than in the adrenals (from 43 to 30 mm in the first, and from 20-57.5 to 30.5 mm in the second adrenal; statistically nonsignificant).

CONCLUSIONS

The lower disease penetrance estimates and sluggish decline of adrenal tumor diameters call for more widespread adoption of adrenal-sparing and parathyroid preservation surgery based on early and regular biochemical screening.

Pheochromocytoma and paraganglioma-an update on diagnosis, evaluation, and management

Pheochromocytomas and paragangliomas (PPGLs) generally grouped together are rare catecholamine-secreting endocrine tumors. Symptoms of catecholamine excess are non-specific and therefore a high index of suspicion in children with sustained hypertension, family history of endocrine tumors, or features of syndromes associated with PPGLs leads to a timely diagnosis and treatment. Free metanephrines in the plasma or 24-h urine are the preferred tests to establish catecholamine excess. Considerations for false-positive conditions improve diagnostic yield and accuracy. Functional imaging, targeting either specific cell membrane transporters or vesicular catecholamine transport systems, is indicated for incidental lesions suspicious for PPGLs with inconclusive biochemical testing, assessment of regional extension or multifocality, and exclusion of metastases. Surgery is the mainstay of treatment for PPGLs. Preoperatively, sequential use of alpha adrenergic receptor blockade and volume expansion followed by beta blockade is mandatory to reduce intraoperative intravascular instability and blood pressure fluctuation due to tumor manipulation. Since genetic mutations have been reported in tumor susceptibility genes in nearly 50% of patients with PPGLs, genetic counselling and testing should be considered in all patients with a confirmed tumor.

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.

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.

Organ-sparing procedures in GU cancer: part 1-organ-sparing procedures in renal and adrenal tumors: a systematic review

PURPOSE

Organ-sparing surgery (OSS) for the kidney and adrenals has emerged as the need for preservation of function is paramount in patients with poor functional reserve. As reports increasingly showed that oncological outcomes were equivalent to radical excision, elective OSS became a viable alternative in patients with otherwise normal reserve. In this review, we summarize the current knowledge of OSS for adrenal and renal tumors.

MATERIALS AND METHODS

PubMed, Web of Science and Cochrane Library Central Search were searched for recently published articles up to December 2017. The following keywords were used; "partial adrenalectomy", "adrenal sparing", "partial nephrectomy", "nephron sparing", "kidney/renal cancer".

RESULTS

Partial adrenalectomy became an attractive alternative to total adrenalectomy avoiding adrenal insufficiency. Both minimally invasive surgery and ablative techniques were increasingly reported for adrenal OSS with adequate residual adrenal function and excellent oncological outcome. Radical nephrectomy remained for many years as the gold standard of treatment for organ-confined renal cell carcinoma. As the need to reduce the impact on renal function, more conservative approaches were utilized. Soon, the non-inferiority of nephron-sparing surgery to that of radical excision became evident and elective partial nephrectomy was gaining ground as the standard of care for small renal masses in patients with normal contralateral kidneys.

CONCLUSIONS

Herein, we present a comprehensive review of the current status of OSS in renal and adrenal tumors.

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.

Review of Pediatric Pheochromocytoma and Paraganglioma

Pheochromocytoma (PCC) and paraganglioma (PGL) are rare chromaffin cell tumors which secrete catecholamines and form part of the family of neuroendocrine tumors. Although a rare cause of secondary hypertension in pediatrics, the presentation of hypertension in these patients is characteristic, and treatment is definitive. The gold standard for diagnosis is via measurement of plasma free metanephrines, with imaging studies performed for localization, identification of metastatic lesions and for surgical resection. Preoperative therapy with alpha-blocking agents, beta blockers, and potentially tyrosine hydroxylase inhibitors aid in a safe pre-, intra- and postoperative course. PCC and PGL are inherited in as much as 80% of pediatric cases, and all patients with mutations should be followed closely given the risk of recurrence and malignancy. While the presentation of chromaffin cell tumors has been well described with multiple endocrine neoplasia, NF1, and Von Hippel-Lindau syndromes, the identification of new gene mutations leading to chromaffin cell tumors at a young age is changing the landscape of how clinicians approach such cases. The paraganglioma-pheochromocytoma syndromes (SDHx) comprise familial gene mutations, of which the SDHB gene mutation carries a high rate of malignancy. Since the inheritance rate of such tumors is higher than previously described, genetic screening is recommended in all patients, and lifelong follow-up for recurrent tumors is a must. A multidisciplinary team approach allows for optimal health-care delivery in such children. This review serves to provide an overview of pediatric PCC and PGL, including updates on the preferred methods of imaging, guidelines on gene testing as well as management of hypertension in such patients.

MANAGEMENT OF ENDOCRINE DISEASE: Recurrence or new tumors after complete resection of pheochromocytomas and paragangliomas: a systematic review and meta-analysis

OBJECTIVES

To systematically review the incidence and factors associated with recurrences or new tumors after apparent complete resection of pheochromocytoma or thoraco-abdomino-pelvic paraganglioma.

DESIGN

A systematic review and meta-analysis of published literature was performed.

METHODS

Pubmed and Embase from 1980 to 2012 were searched for studies published in English on patients with non-metastatic pheochromocytoma or thoraco-abdomino-pelvic paraganglioma, complete tumor resection, postoperative follow-up exceeding 1 month, and recurrence or new tumor documented by pathology, hormonal dosages, or imaging tests. Incidence rates of new events after curative surgery were calculated for each study that had sufficient information and pooled using random-effect meta-analysis.

RESULTS

In total, 38 studies were selected from 3518 references, of which 36 reported retrospective cohorts from the USA, Europe, and Asia. Patient follow-up was neither standardized nor exhaustive in the included studies. A clear description of patient retrieval methods was available for nine studies and the follow-up protocol and patient flow for four studies. Only two studies used multivariable methods to assess potential predictors of postoperative events.The overall rate of recurrent disease from 34 studies was 0.98 events/100 person-years (95% confidence interval 0.71, 1.25). Syndromic diseases and paragangliomas were consistently associated with a higher risk of a new event in individual studies and in meta-regression analysis.

CONCLUSIONS

The risk of recurrent disease after complete resection of pheochromocytoma may be lower than that previously estimated, corresponding to five events for 100 patients followed up for 5 years after complete resection. Risk stratification is required to tailor the follow-up protocol after complete resection of a pheochromocytoma or paraganglioma. Large multicenter studies are needed to this end.

Pheochromocytoma in Neurofibromatosis Type 1: When Should it Be Suspected?

OBJECTIVE

Neurofibromatosis type 1 (NF1) carries an increased risk of pheochromocytoma. Most experts recommend that NF1 patients be screened for pheochromocytoma if hypertension develops. We sought to compare NF1 and non-NF1 patients with pheochromocytoma.

METHODS

Retrospective analysis of a prospectively collected database of all patients undergoing pheochromocytoma resection by a single surgeon from 2003-2012. Statistical significance was evaluated using Fisher's exact test for categorical variables and the Wilcoxon rank sum test for continuous variables.

RESULTS

Of 56 patients undergoing pheochromocytoma resection, 6 (11%) had NF1. All 6 (100%) NF1 patients had pheochromocytoma diagnosed incidentally during work-up for another condition, whereas 28 of 50 (56%) non-NF1-associated pheochromocytomas were diagnosed incidentally (P = .071). Hypertension was present in 1 (17%) NF1 patient and in 37 (74%) of the non-NF1 patients (P = .011). Tumors were significantly smaller in NF1 patients compared with non-NF1 patients (median tumor dimension, 2.75 cm vs. 5.9 cm, respectively; P = .014).

CONCLUSION

Although NF1 patients have a well-known increased risk of developing pheochromocytoma, in the current series, all NF1 patients referred to the surgeon for adrenalectomy had pheochromocytoma diagnosed incidentally. Nevertheless, NF1 patients had significantly smaller tumors and less hypertension than other patients treated for pheochromocytoma, perhaps due to a higher frequency of imaging occasioned by their other neoplasms. The common recommendation to screen for pheochromocytoma when hypertension develops would have failed to spur screening in 83% of these NF1 patients. Routine screening for pheochromocytoma in all NF1 patients may be warranted after evaluating whether this is cost-effective in reducing morbidity and mortality.

Phaeochromocytoma and Paraganglioma

Phaeochromocytomas and paragangliomas are relatively uncommon tumours which may be manifest in many ways, specifically as sustained or paroxysmal hypertension, episodes of palpitations, sweating, headache and anxiety, or increasingly as an incidental finding. Recent studies have shown that an increasing number are due to germline mutations. This review concentrates on the diagnosis, biochemistry and treatment of these fascinating tumours.

Tau missorting and spastin-induced microtubule disruption in neurodegeneration: Alzheimer Disease and Hereditary Spastic Paraplegia

In Alzheimer Disease (AD), the mechanistic connection of the two major pathological hallmarks, namely deposition of Amyloid-beta (Aβ) in the form of extracellular plaques, and the pathological changes of the intracellular protein Tau (such as phosphorylation, missorting, aggregation), is not well understood. Genetic evidence from AD and Down Syndrome (Trisomy 21), and animal models thereof, suggests that aberrant production of Aβ is upstream of Tau aggregation, but also points to Tau as a critical effector in the pathological process. Yet, the cascade of events leading from increased levels of Aβ to Tau-dependent toxicity remains a matter of debate.

Using primary neurons exposed to oligomeric forms of Aβ, we have found that Tau becomes mislocalized (missorted) into the somatodendritic compartment. Missorting of Tau correlates with loss of microtubules and downstream consequences such as loss of mature spines, loss of synaptic activity, and mislocalization of mitochondria.

In this cascade, missorting of Tau induces mislocalization of TTLL6 (Tubulin-Tyrosine-Ligase-Like 6) into the dendrites. TTLL6 induces polyglutamylation of microtubules, which acts as a trigger for spastin mediated severing of dendritic microtubules. Loss of microtubules makes cells unable to maintain transport of mitochondria, which in turn results in synaptic dysfunction and loss of mature spines. These pathological changes are absent in TauKO derived primary neurons. Thus, Tau mediated mislocalization of TTLL6 and spastin activation reveals a pathological gain of function for Tau and spastin in this cellular model system of AD.

In contrast, in hereditary spastic paraplegia (HSP) caused by mutations of the gene encoding spastin (spg4 alias SPAST), spastin function in terms of microtubule severing is decreased at least for the gene product of the mutated allele, resulting in overstable microtubules in disease model systems. Whether total spastin severing activity or microtubule stability in human disease is also affected is not yet clear. No human disease has been associated so far with the long-chain polyglutamylation enzyme TTLL6, or the other TTLLs (1,5,11) possibly involved.

Here we review the findings supporting a role for Tau, spastin and TTLL6 in AD and other tauopathies, HSP and neurodegeneration, and summarize possible therapeutic approaches for AD and HSP.

Molecular imaging in hereditary succinate dehydrogenase mutation-related paragangliomas

Multiple paraganglioma (PGL) syndromes related to succinate dehydrogenase (SDH) gene mutations are rare hereditary conditions. These present with heterogeneous clinical signs and symptoms and in many cases are difficult to classify. We summarize the pathophysiological, clinical, laboratory, and morphological and functional imaging characteristics of SDH gene mutation PGLs, emphasizing F-FDG and F-DOPA PET/CT. We correlate clinical and genetic features of SDH-related PGLs with specific PET radiopharmaceuticals, with the aim to obtain an "individualized" diagnostic approach.

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.

Laparoendoscopic single-site (LESS) retroperitoneal partial adrenalectomy using a custom-made single-access platform and standard laparoscopic instruments: technical considerations and surgical outcomes

BACKGROUND

We previously reported our initial experience with laparoendoscopic single-site (LESS) retroperitoneal partial adrenalectomy using a custom-made single-port device and conventional straight laparoscopic instruments.

METHODS

Between December 2010 and February 2012, LESS retroperitoneal partial adrenalectomies were performed in 11 patients. Six patients had aldosterone-producing adenomas (APAs) and five patients had nonfunctioning tumors. A single-port access was created with an Alexis wound retractor (Applied Medical, Rancho Santa Margarita, CA, USA) through an incision of 2-3 cm beneath the tip of the 12th rib. All procedures were performed with straight laparoscopic instruments.

RESULTS

All LESS procedures were successfully completed without conversion to traditional laparoscopic conversion. The tumors ranged from 1 cm to 4.7 cm (mean, 2.3 cm). The operative time was 71-257 minutes (mean, 121 minutes). Most patients (n = 8) had minimal blood loss; the other three patients had a blood loss of 150 mL, 100 mL, and 100 mL. The mean hospital stay was 3 days (range, 1-6 days). There were no perioperative or postoperative complications. Pathological examinations revealed negative surgical margins in all specimens. All patients with Conn's syndrome had an improvement in blood pressure and normalization of plasma renin activity and serum aldosterone levels; all patients were free of potassium supplementation.

CONCLUSION

Our results clearly demonstrate that LESS retroperitoneal partial adrenalectomy can be performed safely and effectively using a custom-made single-access platform and standard laparoscopic instruments.

Diagnosis and treatment of adrenal medullary hyperplasia: experience from 12 cases

Objective. To dissect the characteristics of adrenal medullary hyperplasia (AMH) and share our experience of diagnosis and treatment of AMH. Methods. From 1999 to 2013, 12 cases of AMH have been pathologically diagnosed after operation in our hospital. The clinical characteristics, process of diagnosis, treatment, and prognosis during follow-up of all patients are summarized retrospectively. Results. Four cases were trended to be AMH and 6 cases were trended to be pheochromocytoma before operation; moreover, the other two patients were diagnosed accidentally. All patients, except for the patient with mucinous tubular and spindle cell carcinoma of left kidney by open surgery, experienced a smooth laparoscopic adrenalectomy, including 2 with radical nephrectomy, 10 of which experienced unilateral adrenalectomy, 1 was bilaterally partial adrenalectomy, and the remaining one was unilaterally complete removal and then 2/3 partially contralateral excision. After a medium follow-up of 6.5 years, it demonstrated a satisfactory outcome of 8 cured patients and 4 symptomatic improved patients. Conclusions. AMH presents a mimicking morphology and clinical manifestation with pheochromocytoma. Surgery could be the only effective choice for the treatment of AMH and showed a preferable prognosis after a quite long follow-up.

The utility of cortical-sparing adrenalectomy in pheochromocytomas associated with genetic syndromes

Management of pediatric patients with pheochromocytomas associated with genetic syndromes, such as Von Hippel-Lindau (VHL) disease, is complex owing to the need for continuous surveillance, high rates of recurrence, multiple operations during childhood, and the possibility of lifelong exogenous steroid replacement. We report the successful treatment of two siblings with VHL who underwent a total of six cortical-sparing procedures without requiring steroid therapy.

High penetrance of pheochromocytoma in multiple endocrine neoplasia 2 caused by germ line RET codon 634 mutation in Japanese patients

OBJECTIVE

The precise penetrance of pheochromocytoma (PHEO) in multiple endocrine neoplasia type 2 (MEN2) has not been reported in a large cohort. In this study, we aimed to clarify the codon-specific penetrance of PHEO in MEN2.

DESIGN

We established a study group designated the 'MEN Consortium of Japan' in 2008 and asked physicians and surgeons to provide clinical and genetic information on patients they had treated up to 2011.

METHODS

Data were collected on patients identified as carriers of the RET mutation or diagnosed with medullary thyroid carcinoma (MTC) and/or PHEO with family history from 52 institutions all over Japan.

RESULTS

Of 493 registered MEN2 patients, RET mutation data were available for 390. Of these, 144 developed PHEOs, while 246 did not. The penetrance of PHEO was 25% by age 30 years, 52% by age 50 years, and 88% by age 77 years in RET mutation carriers with a codon 634 mutation. All patients with a codon 918 mutation (MEN2B) developed PHEO by age 56 years. Less than 32%penetrance of PHEO was seen in patients with mutations at codons other than 634 and 918.

CONCLUSIONS

Most patients with a codon 634 mutation develop PHEOs as well as MTC during their lifetime.

P.Arg82Leu von Hippel-Lindau (VHL) gene mutation among three members of a family with familial bilateral pheochromocytoma in India: molecular analysis and in silico characterization

Various missense mutations in the VHL gene have been reported among patients with familial bilateral pheochromocytoma. However, the p.Arg82Leu mutation in the VHL gene described here among patients with familial bilateral pheochromocytoma, has never been reported previously in a germline configuration. Interestingly, long-term follow-up of these patients indicated that the mutation might have had little impact on the normal function of the VHL gene, since all of them have remained asymptomatic. We further attempted to correlate this information with the results obtained by in silico analysis of this mutation using SIFT, PhD-SNP SVM profile, MutPred, PolyPhen2, and SNPs&GO prediction tools. To gain, new mechanistic insight into the structural effect, we mapped the mutation on to 3D structure (PDB ID 1LM8). Further, we analyzed the structural level changes in time scale level with respect to native and mutant protein complexes by using 12 ns molecular dynamics simulation method. Though these methods predict the mutation to have a pathogenic potential, it remains to be seen if these patients will eventually develop symptomatic disease.

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.

Outcome of surgery for primary hyperaldosteronism

BACKGROUND

Primary hyperaldosteronism (PHA) frequently causes secondary hypertension and is a surgically amenable disease if associated with unilateral adenoma. Patients who underwent laparoscopic adrenalectomy at the authors' department were followed to identify clinical parameters that predict resolution of hypertension.

METHODS

All patients with PHA and adrenalectomy from 1993 to 2009 were identified. Charts and follow-up data were reviewed for clinical parameters and hormone levels. Univariate and multivariate analysis were performed with SPSS 15.0.

RESULTS

A cohort of 30 female and 24 male patients underwent laparoscopic adrenalectomy. Hypokalemia was observed in 47/54 (87%) patients. Twenty patients (37%) were cured without any further need of antihypertensive medication, 20 (37%) patients experienced an improvement in hypertension, and 14 (26%) patients remain unaffected. Consequently, hypertension was resolved or improved in 40/54 (74%) patients. A shorter duration of hypertension (<6 years), the number of antihypertensive drugs (<3), and the serum creatinine level (<1.3 mmol/l) were independent predictors of resolution of hypertension in a multivariate analysis. At final follow-up after a mean of 49 ± 40 months, resolution of hypertension was observed in 17/30 (57%) patients. Interestingly, in 10/17 patients a period longer than 12 months was required before a resolution of hypertension was observed. Coexistent hyperplasia, which was observed in 30% of patients, did not correlate with outcome.

CONCLUSIONS

In 50% of patients with PHA, hypertension resolves after laparoscopic adrenalectomy, but the process may require more than 12 months. Patients with a duration of hypertension of more than 6 years, more than 3 antihypertensive drugs, and elevated serum creatinine have a higher risk of persistent hypertension after surgery. Coexistent hyperplasia in the resected adrenal gland is not associated with persistent hypertension.

Paragangliomas and paraganglioma syndromes

Paragangliomas are rare tumors of neural crest origin. They are benign in the majority of cases and are characterized by a strong vascularisation.

In the head and neck region they most commonly occur as carotid body tumors. Jugulotympanic and especially vagal paragangliomas are seen less frequently. Complete surgical resection represents the only curative treatment option even though resection of locally advanced tumors regularly results in lesions of the lower cranial nerves and major vessels.

Appoximately 30% of all head and neck paragangliomas (HNPs) are hereditary and associated with different tumor syndromes. The paraganglioma syndromes 1, 3 and 4 (PGL 1, 3 and 4) make up the majority of those familial cases. PGL 1 is associated with mutations of the succinate dehydrogenase subunit D (SDHD) gene, PGL 3 is caused by SDHC and PGL 4 by SDHB gene mutations. Multiple HNPs and the occurance of HNPs together with pheochromocytomas are seen in SDHD as well as SDHB mutation carriers. In patients with SDHB mutations the risk for the development of malignant paraganglial tumors is significantly higher compared to SDHC and SDHD patients as well as patients with sporadic tumors. SDHC mutation carriers almost exclusively present with benign HNP that are unifocal in the majority of cases. The role of transmission is autosomal dominant for all three symptoms. Interestingly, there is a “parent-of-origin-dependent-inheritance” in subjects with SDHD gene mutations. This means that the disease phenotype may only become present if the mutation is inherited through the paternal line. We recommend screening for mutations of the genes SDHB, SDHC and SDHD in patients with HNPs. Certain clinical parameters can help to set up the order in which the three genes should be tested.

Pheochromocytoma - update on disease management

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

Clinical features of paraganglioma syndromes

Head and neck paragangliomas (HNPs) and pheochromocytomas are rare tumors. Sporadic and hereditary forms are recognized. Four different paraganglioma syndromes (PGLs 1-4) have been described: PGL 1 is associated with mutations of the succinate dehydrogenase (SDH) subunit D (SDHD) gene; PGL 3 is caused by SDHC gene mutations; PGL 4 is caused by SDHB gene mutations; the susceptibility gene for PGL 2 is unknown. The objective of this study is to review distinct clinical features of the different PGLs. An international registry for HNPs was founded in Freiburg, Germany, in 2000. The data presented in this article have been acquired from registered HNP patients who have been screened for mutations of the genes SDHB, SDHC, and SDHD. Approximately 30% of apparent sporadic HNPs are caused by a germline mutation in one of these genes. Patients with PGL 1 or 4 have a very high lifetime risk of developing HNPs as well as thoracic and abdominal pheochromocytomas. Compared with sporadic HNPs, tumors developing in SDHB, SDHC, and SDHD mutation carriers arise at a significantly younger age. The SDHB mutations are associated with a high percentage of malignant paraganglionic tumors. We recommend molecular genetic screening of all HNP patients for SDHB, SDHC, and SDHD gene mutations. Mutation carriers must be screened for paraganglial tumors in the head, neck, thorax, and abdomen. Appropriately timed surgical intervention will minimize disease-specific morbidity and mortality. Lifelong follow-up is mandatory.

Novel germline SDHD mutation: diagnosis and implications to the patient

A 54-year-old man presented with hypertensive crisis. He was found to have bilateral pheochromocytomas and left paraaortic sympathetic paraganglioma. Although he had no family history of paragangliomas or pheochromocytomas, he had been diagnosed with bilateral head and neck paragangliomas 10 years prior. The patient had symptoms of catecholamine excess exacerbated by vanilla ice-cream consumption. Biochemical testing revealed elevated plasma-free metanephrines and chromogranin A levels. Computed tomography showed bilateral carotid body tumors and four reteroperitoneal masses (two in the right adrenal, one in the left adrenal and one in the left paraaortic area). Metaiodobenzylguanidine-SPECT scans showed functional tumors in both the adrenal gland and left paraaortic area. Fluorine 18-fluorodeoxyglucose positron emission tomography did not show any visceral or skeletal metastasis. We carried out gene mutation analysis for succinate dehydrogenase complex subunit B, and succinate dehydrogenase complex subunit D. The patient was diagnosed with hereditary paraganglioma syndrome type 1 with a previously unreported subunit D mutation in exon 3 (c.198G > A, p.W66X). He was treated with phenoxybenzamine at 10 mg/day and with metoprolol at 12.5 mg/day. His blood pressures as well as symptoms of catecholamine excess were controlled. He then underwent bilateral adrenalectomy and reteroperitoneal dissection. His blood pressure normalized and he discontinued antihypertensive medications after surgery. He is currently on replacement therapy with hydrocortisone and fludrocortisone.

Outcomes and timing for intervention of partial adrenalectomy in patients with a solitary adrenal remnant and history of bilateral phaeochromocytomas

OBJECTIVE

To evaluate the outcomes and timing of intervention for adrenal-sparing surgery in patients left with a solitary adrenal remnant after bilateral adrenal surgeries.

PATIENTS AND METHODS

Patients were included in the study if they had undergone bilateral adrenal surgery as a treatment for phaeochromocytoma and were left with a solitary adrenal remnant. Perioperative, functional and oncological outcomes were evaluated in 21 patients who met the inclusion criteria.

RESULTS

There was minimal perioperative morbidity and no perioperative mortality. After a median (range) follow-up of 21 (3-143) months, there were two cases of persistent disease. Ten patients (48%) required steroid supplementation upon discharge, with four subsequently discontinuing this treatment. Patients were more likely to require steroid supplementation after surgery if they underwent simultaneous adrenalectomy and contralateral partial adrenalectomy, rather than staged procedures (86 vs 40%, P = 0.02). Patients who underwent surgery for tumours > 4 cm were more likely to require long-term steroids than patients who underwent surgery for lesions < 4 cm (75 vs 18%, P = 0.05).

CONCLUSIONS

Patients left with a solitary adrenal remnant after bilateral adrenal surgery have low surgical morbidity, reasonable functional outcomes and low rates of recurrence at an intermediate follow-up period. A staged approach could decrease the immediate postoperative need for steroids, and intervention before the largest tumour reaches 4 cm could decrease the rate of long-term steroid dependence.

Neuroendocrine tumors and tumor syndromes in childhood

Endocrine and neuroendocrine cells form a large and diverse array of cell types. They are present in the form of specialized organs, such as the pituitary, parathyroid, thyroid, and adrenal gland, or in the form of the diffuse neuroendocrine system in the respiratory and digestive tracts. Neuroendocrine tumors are a heterogeneous group of neoplasms, yet they present certain unifying features. These include frequent hormonal overproduction that leads to specific symptoms and a typical immunohistochemical staining profile with chromogranin A and synaptophysin reactivity. Over the past decades, many neuroendocrine tumors have been described in the context of heritable tumor syndromes, and there exist several syndromes that are almost entirely composed of neuroendocrine tumors. Tumors occurring as part of these hereditary syndromes are characterized by specific genetic abnormalities that have helped our understanding of tumorigenesis, and they frequently appear at a young age. It is therefore important for the pediatric pathologist to be aware of specific histologic characteristics of neuroendocrine tumors in childhood and of their association with specific tumor syndromes. This may alert other clinicians to the possibility of multiple tumors in the patient or his family members. This review focuses on hereditary syndromes with neuroendocrine tumors, including multiple endocrine neoplasia types 1 and 2, Von Hippel-Lindau disease, neurofibromatosis type 1, Carney complex, pheochromocytoma-paraganglioma syndrome, and familial nonmedullary thyroid carcinoma. In addition, several individual neuroendocrine tumors are described, such as medullary thyroid carcinoma, gastroenteropancreatic tumors, pheochromocytoma, and paraganglioma, emphasizing specific histopathologic characteristics.

Severe hypercortisolism: a medical emergency requiring urgent intervention

OBJECTIVES

To illustrate the importance of recognizing symptoms of severe hypercortisolism in the intensive care unit and key emergency measures to reduce this extreme hypercortisolism.

DESIGN

Case report.

SETTING

Intensive care unit in a university hospital.

PATIENT

A 55-yr-old woman was admitted to the intensive care unit with multiorgan failure after perforation of the sigmoid. Recent-onset hypertension, spontaneous hypokalemia, and diabetes mellitus suggested severe Cushing's syndrome as the underlying disease. Markedly increased serum cortisol (5900 nmol/L) and adrenocorticotropic hormone (302 ng/L) levels were found, highly suggestive for ectopic adrenocorticotropic hormone secretion. Imaging studies failed to unequivocally establish a solitary source of ectopic adrenocorticotropic hormone secretion. The deteriorating condition of the patient urged rapid intervention.

INTERVENTIONS

Etomidate was infused continuously to reduce endogenous adrenal cortisol secretion. Subsequently, a rescue bilateral adrenalectomy was undertaken.

MEASUREMENTS AND RESULTS

Etomidate effectively reduced the cortisol level. Serial blood samples were obtained during the bilateral adrenalectomy. Plasma adrenocorticotropic hormone markedly decreased immediately after resection of the right adrenal gland. Histopathological examination revealed a tumor of the right adrenal gland identified as a pheochromocytoma and hyperplasia of the left adrenal gland, but no signs of malignancy. The patient recovered slowly.

CONCLUSION

This case illustrates that severe hypercortisolism is a medical emergency and that specific and prompt combined medical and surgical intervention can be life-saving.

Partial adrenalectomy: underused first line therapy for small adrenal tumors

PURPOSE

Many patients with small adrenal masses undergo total adrenalectomy. We evaluated partial adrenalectomy outcomes by performing a comprehensive literature review.

MATERIALS AND METHODS

We performed a PubMed search of the English language literature using the queries partial adrenalectomy and adrenal sparing surgery, and identified 317 and 155 articles, respectively. We excluded case reports or series with fewer than 5 patients, articles not focused on surgical management and those that did not indicate perioperative outcomes. The remaining articles were cross-referenced by author and institution to eliminate studies with redundant cases. Demographics, diagnosis, tumor characteristics, perioperative and functional outcomes, and recurrence data were collected when available.

RESULTS

A total of 22 articles from a total of 22 first authors met our inclusion criteria, describing outcomes in a total of 417 patients. There has been an increasing trend toward partial adrenalectomy worldwide in the last 20 years. Partial adrenalectomy is most commonly done for Conn's syndrome, followed by pheochromocytoma. Most procedures are laparoscopic with minimal morbidity. The recurrence rate is only 3% and more than 90% of patients remain steroid independent.

CONCLUSIONS

Partial adrenalectomy surgical outcomes and perioperative complications are similar to those reported for total adrenalectomy. When partial adrenalectomy is done for small adrenal lesions, the malignancy rate is negligible, the recurrence rate is low and most patients remain steroid-free at long-term followup. These data strongly support the acceptance of partial adrenalectomy as first line treatment for small adrenal masses.

Paraganglioma syndrome type 1 in a patient with Carney-Stratakis syndrome

BACKGROUND

A 33-year-old man was referred to a specialist center with a left neck mass and hypertension. The patient underwent surgery, which confirmed a malignant neck paraganglioma with metastasis to a cervical lymph node. He had no family history of carotid body tumors or pheochromocytoma.

INVESTIGATIONS

Measurements of plasma free metanephrines and chromogranin A; radiographic evaluations with CT, (18)F-fluorodeoxyglucose PET and (123)I-labeled metaiodobenzylguanidine scan; gene analysis for mutations in the SDHD and the KIT gene.

DIAGNOSIS

Paraganglioma syndrome type 1 in a patient with a paraganglioma, bilateral pheochromocytomas and a gastrointestinal stromal tumor with a somatic Asp579del KIT mutation.

MANAGEMENT

The patient underwent surgical excision of all tumors after adequate preparation with alpha and beta blockers. Blood pressure normalized after surgery. The patient is examined regularly with biochemical and radiographic studies, and his follow-up is expected to last throughout life.

Phaeochromocytomas and sympathetic paragangliomas

BACKGROUND

About 24 per cent of phaeochromocytomas (PCCs) and sympathetic paragangliomas (sPGLs) appear in familial cancer syndromes, including multiple endocrine neoplasia type 2, von Hippel-Lindau disease, neurofibromatosis type 1 and PCC-paraganglioma syndrome. Identification of these syndromes is of prime importance for patients and their relatives. Surgical resection is the treatment of choice for both PCC and sPGL, but controversy exists about the management of patients with bilateral or multiple tumours.

METHODS

Relevant medical literature from PubMed, Ovid and Embase websites until 2009 was reviewed for articles on PCC, sPGL, hereditary syndromes and their treatment.

DISCUSSION

Genetic testing for these syndromes should become routine clinical practice for those with PCC or sPGL. Patients should be referred to a clinical geneticist. Patients and family members with proven mutations should be entered into a standardized screening protocol. The preferred treatment of PCC and PGL is surgical resection; to avoid the lifelong consequences of bilateral adrenalectomy, cortex-sparing adrenalectomy is the treatment of choice.

Surgical management of MEN-1 and -2: state of the art

Multiple endocrine neoplasia syndrome type 1 (MEN-1) consists of endocrine tumors of the parathyroid, the endocrine pancreas-duodenum, and the pituitary. Surveillance and screening for the endocrinopathies is recommended in gene carriers. Surgery for MEN-1-related hyperparathyroidism is generally performed as radical subtotal parathyroidectomy, because less surgery is likely to result in persistent or recurrent disease. Multiple endocrine neoplasia syndrome type 2 (MEN-2) consists of medullary thyroid carcinoma, pheochromocytoma, and hyperparathyroidism. Prophylactic thyroidectomy based on DNA testing in the MEN-2 syndrome is considered one of the greater achievements in cancer treatment, because it may be performed before thyroid carcinoma development and provides cure for the patient.

Surgical management of nonmultiple endocrine neoplasia endocrinopathies: state-of-the-art review

The development of genetic testing has given patients with familial endocrine diseases the opportunity to be identified earlier in life. The importance of this technological advancement cannot be underestimated, as some of these heritable diseases have significant potential for malignancy. This article focuses on the identification and surgical management of familial endocrinopathies of the thyroid, parathyroid, adrenal glands, and pancreas. Familial endocrinopathies discussed include hereditary nonmedullary carcinoma of the thyroid, Cowden disease, familial adenomatous polyposis, Carney complex, Werner syndrome, familial medullary thyroid carcinoma, Pendred syndrome, hereditary hyperparathyroidism jaw-tumor syndrome, familial isolated hyperparathyroidism, Beckwith- Wiedemann syndrome, Li-Fraumeni syndrome, neurofibromatosis I, von Hippel-Lindau disease, and tuberous sclerosis.