The management of benign and malignant pheochromocytoma and abdominal paraganglioma

Diagnostic tests and biomarkers for pheochromocytoma and extra-adrenal paraganglioma: from routine laboratory methods to disease stratification

The laboratory workup of patients with pheochromocytoma and extra-adrenal paraganglioma (PPGLs) has traditionally focused on biochemical measurements of tumor secretory products or their metabolites, with ultimate diagnosis resting on routine histopathology and immunohistochemistry. While such testing remains important, the needs to distinguish potentially metastatic from benign tumors and to identify tumors with a hereditary basis have stimulated searches for additional means to stratify patients according to risk of metastasis or presence of a particular mutation. Biomarkers based on traditional biochemical tests, such as profiles of catecholamine metabolites and granin-derived peptides, provide utility for both purposes, while novel biomarkers are being identified by proteomic and transcriptomic studies, the latter including microRNA expression profiling. Histopathological scoring methods for predicting metastatic potential, such as the Pheochromocytoma of the Adrenal Gland Scaled Score (PASS), are limited by poor interobserver concordance, discrepant results between studies and incomplete knowledge of how scores relate to genotype. Immunohistochemical staining for succinate dehydrogenase (SDH) subunit B to triage patients for genetic testing of SDH subunit genes illustrates the growing importance of pathology as an adjunct to genetic testing for disease stratification. Although considerable effort has been expended on microarray-based platforms to identify biomarkers of malignancy, as yet, none of those proposed have been demonstrated to reliably discriminate malignant from benign disease any better than the PASS. Because of the heterogeneity of PPGLs and variable time between first appearance of tumors and identification of metastases, any prospective study to establish prognostic efficacy requires large numbers of patients and extended follow-up.

Malignant pheochromocytomas and paragangliomas: a diagnostic challenge

INTRODUCTION

Malignant pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare disorders arising from the adrenal gland, from the glomera along parasympathetic nerves or from paraganglia along the sympathetic trunk. According to the WHO classification, malignancy of PCCs and PGLs is defined by the presence of metastases at non-chromaffin sites distant from that of the primary tumor and not by local invasion. The overall prognosis of metastasized PCCs/PGLs is poor. Surgery offers currently the only change of cure. Preferably, the discrimination between malignant and benign PCCs/PGLs should be made preoperatively.

METHODS

This review summarizes our current knowledge on how benign and malignant tumors can be distinguished.

CONCLUSION

Due to the rarity of malignant PCCs/PGLs and the obvious difficulties in distinguishing benign and malignant PCCs/PGLs, any patient with a PCC/PGL should be treated in a specialized center where a multidisciplinary setting with specialized teams consisting of radiologists, endocrinologist, oncologists, pathologists and surgeons is available. This would also facilitate future studies to address the existing diagnostic and/or therapeutic obstacles.

Comparison of diagnostic value of I-123 MIBG and high-dose I-131 MIBG scintigraphy including incremental value of SPECT/CT over planar image in patients with malignant pheochromocytoma/paraganglioma and neuroblastoma

PURPOSE

to compare lesion detectability of I-123 MIBG scintigraphy with that of high-dose I-131 MIBG and to evaluate incremental benefit of SPECT/CT over planar image for the detection and localization of the lesions in patients with I-131 MIBG therapy for malignant pheochromocytoma/paraganglioma and neuroblastoma.

MATERIALS AND METHODS

we retrospectively investigated 16 patients with malignant pheochromocytoma/paraganglioma and neuroblastoma, who were referred for I-131 MIBG therapy. We investigated the lesion detectability in 10 pairs of I-123 and high-dose I-131 MIBG studies of the same patient, obtained within 2 weeks. In 31 studies of I-123 MIBG scintigraphy in 16 patients and 17 studies of high-dose I-131 MIBG scintigraphy in 12 patients, we compared planar and SPECT/CT images for the lesion detectability and localization.

RESULTS

the number of lesions detected by I-123 MIBG planer image and SPECT/CT and high-dose planer I-131 MIBG and SPECT/CT were 3.0 and 3.7, 7.3 and 7.7 per study, respectively. SPECT/CT images provided additional diagnostic information over planar images in 25 studies (81%) of 12 patients (75%) in I-123 MIBG scintigraphy and in 9 studies (53%) of 9 patients (75%) in high-dose I-131 MIBG scintigraphy.

CONCLUSION

post-therapy high-dose I-131 MIBG scintigraphy is superior to I-123 MIBG scintigraphy in lesion detectability even in comparison with I-123 MIBG SPECT/CT images and high-dose I-131 MIBG planar images in patients with malignant neuroendocrine tumors. SPECT/CT images are helpful for accurate identification of anatomic localization compared with planar images.

Predictive factors for malignant pheochromocytoma: analysis of 136 patients

PURPOSE

We evaluated the clinical characteristic, tumor feature and immunohistochemistry factors predicting malignant pheochromocytoma.

MATERIALS AND METHODS

Between January 1999 and December 2008 we retrospectively reviewed the records of 136 patients with pheochromocytoma at Ruijin Hospital. We compared clinical characteristics (age, gender, symptoms and biochemical analysis), tumor features (site, weight and diameter) and the expression of 3 angiogenesis/metastasis related genes (VEGF, Cox-2 and MVD) by immunohistochemical analysis of benign vs malignant pheochromocytomas.

RESULTS

Of the 136 patients 105 (77%) had benign and 31 (23%) had malignant pheochromocytoma. Malignant tumors were larger and heavier than benign tumors, and accompanied by higher plasma metanephrine secretion (each p <0.001). Mean tumor catecholamine and preoperative 24-hour urinary metanephrine or normetanephrine were obviously higher in malignant than in benign tumors (p <0.001). Also, 25 malignant tumors (81%) were immunopositive for VEGF while only 24 benign tumors (23%) showed this characteristic (p <0.001). Microvessel density and the rate of positive staining for Cox-2 protein in malignant samples were higher than in benign samples (p <0.001).

CONCLUSIONS

Several promising predictive parameters are currently available to distinguish benign from malignant pheochromocytoma. Large (5 cm or greater) or heavy (250 gm or greater) tumors, multifocal and extra-adrenal tumors, early onset postoperative hypertension and higher plasma or urine metadrenaline are high risk factors predictive of malignant pheochromocytoma. Also, expression of the 3 angiogenesis or metastasis related genes VEGF, Cox-2 and MVD helps determine the diagnosis of malignancy and suggests strict followup.

Malignant pheochromocytoma: a review

BACKGROUND

Pheochromocytomas are rare catecholamine-secreting tumors. Approximately 10 percent of pheochromocytomas are malignant. Traditionally, there has been no reliable method available to predict the malignant potential of pheochromocytoma. However, recent research has increased focus on differentiating at the time of surgery/diagnosis those pheochromocytoma tumors which have malignant potential. In this review, we discuss the current information known of malignant pheochromocytomas.

DATA SOURCES

The PubMed database was searched for articles on malignant pheochromocytoma published between 1993 and 2010.

CONCLUSIONS

The difficult task of predicting the malignant potential of a pheochromocytoma has yet to be answered definitively. However, all the studies presented give an idea of what we may look for in these tumors at the time of diagnosis. We have provided an algorithm based on the most current information known. A much larger study should be performed to test many of these theories with enough power to determine a standard of care.

Childhood phaeochromocytoma and paraganglioma: 100% incidence of genetic mutations and 100% survival

INTRODUCTION

The aim is to identify the incidence of genetic mutations and outcome of children presenting with phaeochromocytoma/paraganglioma (PGL) to a single paediatric surgical service to determine the need for genetic counselling in associated kindreds.

METHODS

A retrospective case note review was undertaken of all cases treated between 1998 and 2008 with particular reference to presentation, management, and predisposing genetic conditions.

RESULTS

Seven cases (4 male, 3 female) were identified (median age, 13 years; interquartile range, 9-16). Three cases had a family history of phaeochromocytoma/PGL. All presented with neurologic symptoms related to hypertension, including headaches (n = 5), hemiparesis (n = 2), facial palsy, and hemianopia. All underwent surgical resection. Five patients had meta-iodobenzylguanidine (MIBG) therapy for apparently malignant features. All cases were found to have a predisposing genetic mutation: von Hippel-Lindau (n = 3), succinate dehydrogenase mutations (n = 3), and multiple endocrine neoplasia (n = 1). All patients are alive after a median follow-up of 5 (interquartile range, 2-7) years.

CONCLUSIONS

All 7 cases had a familial genetic mutation identified, and none arose de novo. We advocate genetic counselling for all families of children diagnosed with phaeochromocytoma/PGL with lifelong surveillance tailored to the underlying syndrome because of the increased risk of synchronous and metachronous tumours associated with these genetic syndromes.

Successful outcome after resection of liver metastasis arising from an extraadrenal retroperitoneal paraganglioma that appeared 9 years after surgical excision of the primary lesion

A 54-year-old man underwent surgery for excision of a retroperitoneal tumor that measured 12 cm in diameter, and histopathological examination revealed the tumor was an extraadrenal retroperitoneal paraganglioma. He presented 9 years later with epigastric discomfort. Abdominal ultrasound showed a solitary liver tumor. The diagnosis, based on radiological workup, was metastatic paraganglioma. The tumor was surgically resected and the histological findings resembled those of the primary tumor. The patient has been followed up for 3 years and remains recurrence-free. Surgical resection is an effective treatment approach for primary and secondary paragangliomas, but the resectability of liver metastatic lesions is usually low, although complete resection with a wide surgical margin was possible in this patient. This case suggests that a good prognosis after the resection of hepatic metastasis depends not only on the curative resection of the metastatic lesion but also on the tumor characteristics, such as slow growth or low aggressiveness.

Treatment of malignant pheochromocytoma

Pheochromocytoma (PCC) is a rare disease, mainly sporadic, but also associated with some familial disorders, with a malignancy frequency of approximately 10%. Only the presence of distant metastases, derived from large pleomorphic chromaffin cells, is widely accepted as a criterion of malignancy. Variable symptoms may be caused by production and release of catecholamines. Since there is no curative treatment for malignant PCC and due to its unfavorable prognosis, assuring quality of life is one of the main therapeutic objectives. Besides a long-term medical treatment of symptoms using selective alpha-1 blockers and nonselective, noncompetitive alpha- and/or beta-blockers, debulking surgery is the first treatment step. In case of a sufficient uptake of (123)I-MIBG treatment with targeted radiation therapy, use of (131)I-MIBG is an option as an adjuvant therapy, following debulking surgery. Chemotherapy should be applied to patients without positive MIBG-scan, with no response to (131)I-MIBG or progression after radionuclide treatment, and especially in cases with high proliferation index. The most effective chemotherapy regimen appears to be the CVD-scheme, including cyclophosphamide, vincristine, and dacarbazine. The so-called targeted molecular therapies with treatment combinations of temozolomide and thalidomide, or sunitinib monotherapy, and novel therapeutic somatostatin analogues have shown promising results and should thus encourage clinical trials to improve the prognosis of metastatic PCC. Within this review the current treatment modalities and novel molecular strategies in the management of this disease are discussed and a treatment algorithm is suggested.

Genetic markers for the diagnosis and prognosis of pheochromocytoma

The last 5 years have witnessed important advances in understanding the mechanisms of tumorigenesis of chromaffin cells. Large-scale microarray analyses of pheochromocytomas have identified two distinct gene-expression profiles encompassing all hereditary and sporadic tumors. Gene-expression profiling of benign and malignant pheochromocytomas is providing a better understanding of the mechanisms of metastasis. Such studies hold promise for the development of new prognostic markers for early detection of malignant pheochromocytoma and for the identification of novel targets for therapeutic intervention.

Treatment of malignant pheochromocytoma/paraganglioma with cyclophosphamide, vincristine, and dacarbazine: recommendation from a 22-year follow-up of 18 patients

BACKGROUND

A long-term follow-up was conducted of 18 patients with a diagnosis of pheochromocytoma/paraganglioma treated with a combination of cyclophosphamide, vincristine, and dacarbazine (CVD).

METHODS

The study design was a nonrandomized, single-arm trial conducted at a government medical referral center. Eighteen patients with metastatic malignant pheochromocytoma/paraganglioma were studied. After controlling symptoms of catecholamine excess, patients were treated with cyclophosphamide at 750 mg/m(2), vincristine at 1.4 mg/m(2), and dacarbazine at 600 mg/m(2) on Day 1 and dacarbazine at 600 mg/m(2) on Day 2, every 21 to 28 days.

RESULTS

Combination chemotherapy with CVD produced a complete response rate of 11% and a partial response rate of 44%. Median survival from a landmark was 3.8 years for patients whose tumors responded to therapy and 1.8 years for patients whose tumors did not respond (P = .65). All patients with tumors scored as responding reported improvement in their symptoms related to excessive catecholamine release and had objective improvements in blood pressure. CVD was well tolerated with only grade I/II toxicities.

CONCLUSIONS

Combination chemotherapy with CVD produced objective tumor responses in patients with advanced malignant pheochromocytoma/paraganglioma. In this 22-year follow-up there was no difference in overall survival between patients whose tumors objectively shrank and those with stable or progressive disease. However, patients reported improvement in symptoms, had objective improvements in blood pressure, and had tumor shrinkage that made surgical resection possible. The authors conclude that CVD therapy is not indicated in every patient with metastatic pheochromocytoma/paraganglioma, but should be considered in the management of patients with symptoms and where tumor shrinkage might be beneficial.

Galanin decreases proliferation of PC12 cells and induces apoptosis via its subtype 2 receptor (GalR2)

Galanin is a neuropeptide with a wide range of effects in the nervous and endocrine systems, mediated through three G protein-coupled receptor subtypes (GalR1-3). Interestingly, galanin and its receptors are also expressed in certain tumors. Here we studied the effects of galanin in rat pheochromocytoma (PC12) cells stably transfected with GFP-tagged GalR2. Galanin at 100 nM inhibited cell proliferation in both nontransfected and transfected cells. Conversly, both galanin and the GalR2(R3)-agonist AR-M1896 induced caspase-dependent apoptotic cell death only in GalR2-transfected cells. Western-blot analyses of downstream mediators of the G(q/11)-type G protein showed down-regulation of pAkt and pBad in galanin-exposed transfected cells. Also, the specific PI3 kinase inhibitor LY-294002 increased the level of pBad and decreased activation of caspases. In addition, p21(cip1) levels were up-regulated in galanin-exposed PC12 cells and down-regulated in galanin-exposed GalR2-transfected cells. In agreement, FACS analyses of galanin exposed cells showed occurrence of cell cycle arrest in PC12 cells and cell death in transfected cells. Finally, as shown with real-time PCR, galanin and its receptors were expressed at very high levels in human pheochromocytoma tissues as compared with normal adrenal medulla. These findings point to GalR2 as a possible target for therapeuthic interventions in pheochromocytoma.

Clinicopathological review of 46 primary retroperitoneal tumors

OBJECTIVES

To clarify the clinical factors including diagnostic imaging findings that may correlate with the histopathological malignancy in primary retroperitoneal tumors.

METHODS

The clinical backgrounds and imaging findings of 22 benign and 24 malignant primary retroperitoneal tumors were retrospectively investigated, and the prognosis of patients with malignant retroperitoneal tumors was assessed.

RESULTS

There were significant correlations between the presence of symptoms and malignancy (P < 0.01), as well as between the irregularity of tumor margins and malignancy (P < 0.01). On dynamic magnetic resonance imaging (MRI), 90% of malignant tumors showed early enhancement either with quick or slow washout, while 75% of benign tumors showed delayed and no enhancement (P < 0.002). All malignant and benign paraganglioma showed the same early enhancement with quick washout. Malignant lymphoma showed various enhancement patterns. The 2-year and 5-year cause-specific survival rates of the patients with malignant retroperitoneal tumors were 68.0% and 43.2%, respectively. All malignant lymphoma patients were mainly treated with chemotherapy after being diagnosed histologically. Malignant paraganglioma patients who could not meet complete resection needed chemotherapy for promising survival.

CONCLUSION

The symptoms, the irregularity of the margins, and the specific enhancement pattern on the dynamic MRI may be important predictive factors of the primary malignant retroperitoneal tumors. Histological diagnosis was needed for malignant definition of paraganglioma because both benign and malignant paraganglioma showed similar clinical and imaging findings. Preoperative biopsy should be considered for selection of the appropriate treatment particularly in patients that are likely to have malignant lymphoma that could not be diagnosed definitively by the clinical and imaging findings.

Malignant pheochromocytoma of the organ of Zuckerkandl requiring aortic and vena caval reconstruction

OBJECTIVE

To describe a case of a malignant pheochromocytoma located in the organ of Zuckerkandl that required aortic and vena caval resection and reconstruction.

METHODS

We present a case report that includes clinical, laboratory, and radiographic data as well as photographs, results from pathology, and a brief review of the literature.

RESULTS

A 46-year-old man was referred for evaluation of a 1.4-cm left adrenal mass incidentally discovered on an abdominopelvic computed tomography (CT) scan. Subsequent laboratory evaluation revealed the following values: urine norepinephrine, 252 microg/24 h; urine normetanephrine, 1122 microg/24 h; urine metanephrine, 162 microg/24 h; urine epinephrine, 7 microg/24 h; urine vanillylmandelic acid, 8 mg/24 h; and plasma metanephrine, 98 pg/ mL. Imaging characteristics of the left adrenal mass were consistent with a benign adenoma, but CT also demonstrated a hypervascular para-aortic mass. 123I-metaiodo-benzylguanidine scanning with fusion CT imaging demonstrated increased radiopharmaceutical uptake within the para-aortic mass consistent with a paraganglioma in the organ of Zuckerkandl. Findings from CT angiography of the abdomen and pelvis suggested aortic involvement and vena caval thrombus. The mass was excised en bloc, including portions of the aorta, inferior vena cava, and right ureter. The aorta and vena cava were reconstructed using Dacron grafts. The remaining right ureter and kidney were removed to avoid the possibility of a urine leak from an ureteroureterostomy. Final pathologic and operative findings confirmed a malignant pheochromocytoma of the organ of Zuckerkandl with invasion into the wall of the inferior vena cava and tumor thrombus extending into the lumen.

CONCLUSION

Malignant pheochromocytoma of the organ of Zuckerkandl involving the aorta and inferior vena cava is exceedingly rare, and although surgical resection and reconstruction can be radical and aggressive, this treatment offers the only chance for cure.

Laparoscopic resection of extra-adrenal pheochromocytoma--case report and review of the literature in pediatric patients

Surgery for pheochromocytoma differs from that of other tumors owing to the potential release of catecholamines, which may lead to severe intraoperative hemodynamic changes. The present standard of care for resection of adrenal pheochromocytoma has become a laparoscopic approach for surgical excision. Extra-adrenal pheochromocytoma is a very rare entity, especially in the pediatric age group; the utility of the laparoscopic approach is not established in this population. We present a case report of a child with hormonally active extra-adrenal pheochromocytoma originating in the organ of Zuckerkandl that was resected laparoscopically. We found the laparoscopic approach gave excellent exposure, allowing for proper identification of the tumor's origin and its relation to surrounding structures; a complete resection with excellent control of the feeding blood vessels was performed. Herein we present the details of this case and a review of the relevant literature. After our initial experience we can recommend laparoscopic exploration for similar cases of suspected extra-adrenal pheochromocytoma as an appropriate tool to identify extension of the disease and estimate resectability. Proper patient preparation and monitoring are critical for success.

Paraganglioma of the greater omentum: Case report and review of the literature

Background

Extra-adrenal, intra-abdominal paraganglioma constitutes a rare neoplasm and, moreover, its location in the greater omentum is extremely infrequent.

Case presentation

A 46-year-old woman with an unremarkable medical history presented with an asymptomatic greater omentum mass that was discovered incidentally during ultrasonographic evaluation due to menstrual disturbances. Clinical examination revealed a mobile, non-tender, well-circumscribed mass in the right upper and lower abdominal quadrant. Blood tests were normal. Contrast-enhanced abdominal computed tomography (CT) scan confirmed a huge (15 × 15 cm), well-demarcated, solid and cystic, heterogeneously enhanced mass between the right liver lobe and right kidney. Exploratory laparotomy revealed a large mass in the greater omentum. The tumor was completely excised along with the greater omentum. Histopathology offered the diagnosis of benign greater omentum paraganglioma. After an uneventful postoperative course, the patient was discharged on the 4^th postoperative day. She remains free of disease for 2 years as appears on repeated CT scans as well as magnetic resonance imaging (MRI) and scintigraphy performed with radiotracer-labeled metaiodobenzyl-guanidine (MIBG) scans.

Conclusion

This is the second reported case of greater omentum paraganglioma. Clinical and imaging data of patients with extra-adrenal, intra-abdominal paragangliomas are variable while many of them may be asymptomatic even when the lesion is quite large. Thorough histopathologic evaluation is imperative for diagnosis and radical excision is the treatment of choice. Since there are no definite microscopic criteria for the distinction between benign and malignant tumors, prolonged follow-up is necessary.

Extra-adrenal pheochromocytoma: Diagnosis and management

Extra-adrenal pheochromocytomas (EAPs) may arise in any portion of the paraganglion system, though they most commonly occur below the diaphragm, frequently in the organ of Zuckerkandl. EAPs probably represent at least 15% of adult and 30% of childhood pheochromocytomas, as opposed to the traditional teaching that 10% of all pheochromocytomas are at extra-adrenal sites. They may be malignant in up to 40% of the cases, though conflicting data add to the uncertainty of this point. Patients with EAPs may present with headache, palpitations, sweating, or hypertension. A small percent of patients may also be asymptomatic at presentation due to nonfunctional tumors. The diagnosis is confirmed by demonstrating elevated blood and urine levels of catecholamines and their metabolites. Imaging studies to evaluate for EAPs include CT, MRI, and (131)I-labelled metaiodobenzylguanidine scintigraphy. Preoperative pharmacologic preparation, attentive intraoperative monitoring, and aggressive surgical therapy have important roles in achieving successful outcomes. Recent reports suggest that a laparoscopic approach, along with intraoperative ultrasound, can safely remove these tumors. EAPs recur and metastasize more often than their adrenal counterparts, making lifelong follow-up essential.

Clinical and pathological data of 10 malignant pheochromocytomas: long-term follow up in a single institute

BACKGROUND

Malignant pheochromocytomas are rare. Many controversies still exists in clinical practice. We report the clinical and histological data of long-term follow up in 10 patients with malignant pheochromocytoma.

METHODS

The clinical charts of 10 patients with malignant pheochromocytoma from a single institute were reviewed. The diagnosis of pheochromocytoma was confirmed at surgery. All patients had metastases in sites where chromaffin tissue was normally absent.

RESULTS

The median follow-up period was 5.5 years (range, 2-20 years). Extra-adrenal tumors occurred in four patients including paraganglioma tumors in three cases and bladder tumor in one case. Regional lymph node metastases were noted in six patients. Distant metastases were located in the lungs of two patients, in the bones of two patients and in the liver of one patient. Histological characteristics were not helpful for diagnosis of malignancy and for prediction of prognosis. Metastases were present in postoperative pathology in seven patients. In another three patients, metastases were discovered 6 months to 10 years after surgery. Three patients received chemotherapy and one patient received combination therapy of high-dose (131)I-meta-iodobenzylguanidine ((131)I-MIBG) therapy and chemotherapy. All patients achieved long-term survival except for two who died of metastasis 1.5 years and 2 years after diagnosis.

CONCLUSIONS

Early complete resection and adjunctive lymphadenectomy can cure malignancy. Close long-term follow up for more than 10 years after surgery is necessary in patients with pheochromocytoma. The possibility of malignancy should be kept in mind even though the initial pathology is benign.

Malignant paraganglioma arising from the kidney

Paragangliomas are rare neoplasms arising from undifferentiated cells of the primitive neural crest. We report a case of a 34-year-old patient with renal paraganglioma. Complete surgical resection of the tumor was performed without intraoperative incident. The diagnosis was made based on immunohistochemical and ultramicroscopic analyses. The postoperative course was uneventful. Based on the obtained results, we discuss the clinical aspects of the case and the diagnosis.

Clinical review: Current treatment of malignant pheochromocytoma

CONTEXT

Pheochromocytomas are rare tumors of predominantly adrenal origin that often produce and secrete catecholamines. Malignancy occurs in a variable percentage of cases depending on genetic background and tumor location. Definitive diagnosis relies on the detection of distant metastases. Treatments for malignant pheochromocytoma include surgical debulking, pharmacological control of hormone-mediated symptoms, targeted methods such as external irradiation, and systemic antineoplastic therapy. Different agents and protocols for this purpose are reviewed, and their therapeutic potential is discussed.

EVIDENCE ACQUISITION

Literature on antineoplastic therapies for malignant pheochromocytoma was identified by searching the PubMed database with restriction to articles published in English during the past 30 yr.

EVIDENCE SYNTHESIS

Because of the rarity of the condition, no randomized clinical trials concerning the treatment of malignant pheochromocytoma have been performed. The strategy established best is [131I]meta-iodobenzylguanidine (MIBG) therapy, which is well tolerated. Similar to cytotoxic chemotherapy with cyclophosphamide, vincristine, and dacarbazine, MIBG can induce remission for a limited period in a significant proportion of patients. Octreotide as a single agent seems to be largely ineffective.

CONCLUSIONS

MIBG radiotherapy and cyclophosphamide, vincristine, and dacarbazine chemotherapy are comparable with respect to response rate and toxicity. It is unclear whether combining both can improve the outcome. Future developments may include new multimodal concepts with focus on inhibition of angiogenetic factors and heat shock protein 90. Any present or new therapeutic approach must take into account the highly variable natural course of the disease.

Malignant pheochromocytoma: state of the field with future projections

The prevalence of malignant pheochromocytoma is about 10%, and is somewhat higher for paraganglioma. A problem for clinical follow-up is that patients with "benign" histopathologic findings may develop metastatic disease. At the first international symposium on pheochromocytoma in Bethesda (2005) experts from different disciplines and patients shared their experiences, and the present knowledge of this rare disease was updated. The discussion related to future strategies for better clinical/histopathologic diagnosis and understanding of different geno- and phenotypes. Curative surgery can only seldom be performed because of multiple metastases. The main therapeutic goal is therefore often tumor reduction and control of hypertension. To date the best adjunct to surgery is radionuclide therapy using 131I-MIBG, but the background information for optimal treatment is still incomplete. Certain patients may benefit from 131I-MIBG combined with radiotherapy via somatostatin receptors expressed by the tumor, or the combination with chemotherapy. The need for future multicenter studies was emphasized. In experimental models the work on enhanced expression of amine transporters critical for radiotherapy is continued. Ongoing microarray studies will reveal novel intracellular pathways of importance for proliferation/cell cycle control, which can be inhibited by pharmacologic tools.

Primary malignant hepatic pheochromocytoma with negative adrenal scintigraphy

A 60-year-old male patient with hypertension was referred to our hospital because of insufficient blood pressure control (190/98 mmHg) and to rule out secondary hypertension. A computed tomography scan revealed no adrenal tumor but a large liver mass (5 x 5 cm), and magnetic resonance imaging showed a high signal intensity lesion on the T2-weighted image. Twenty-four hour urinary excretion of catecholamine metabolites was markedly increased, although a 123I-metaiodobenzyl guanidine (MIBG) scintigram failed to show accumulation in the hepatic mass, and no difference was noted between the catecholamine concentration in the tumor-drainage vein and that obtained from the vein draining from the non-tumor area. Liver biopsy did show features compatible with pheochromocytoma (i.e., chromogranin A-positive cells). Transcatheter arterial embolization of the liver tumor was conducted and resulted in a marked (50%) decrease in the 24-h urine normetanephrine excretion. Several metastatic foci were noted in the spinal bone and transcatheter arterial embolization (TAE) was also conducted with successful results. Thus, we experienced a case of primary malignant hepatic pheochromocytoma with negative 123I-MIBG scanning.

Pheochromocytoma and paraganglioma in children: a review of medical and surgical management at a tertiary care center

OBJECTIVE

The aim of this study was to review our institutional experience managing pheochromocytomas and paragangliomas in children.

METHODS

A retrospective chart review of the Mayo Clinic database from 1975 to 2005 identified 30 patients < 18 years of age with histologically confirmed pheochromocytoma or paraganglioma.

RESULTS

There were 12 patients with pheochromocytomas and 18 with paragangliomas. The most common presenting symptoms were hypertension (64%), palpitation (53%), headache (47%), and mass-related effects (30%). Nine patients (30%) had a genetic mutation or documented family history of pheochromocytoma or paraganglioma. Fourteen patients (47%) had malignant disease, whereas 16 (53%) had benign disease. Logistic analysis showed that statistically significant risk factors for malignancy were (1) paraganglioma, (2) apparently sporadic, as opposed to familial, pheochromocytoma or paraganglioma, and (3) tumor size of > 6 cm. Surgical resection was performed for 28 patients (93%), with perioperative mortality and major morbidity rates of 0% and 10%, respectively. Resection achieved symptomatic relief for 25 patients (83%). All patients with benign disease appeared cured after resection. For patients with malignant disease, the 5- and 10-year disease-specific survival rates were 78% and 31%, respectively, and the mean survival time was 157 +/- 32 months.

CONCLUSIONS

The incidence of malignant pheochromocytoma/paraganglioma was high in children (47%), particularly those with apparently sporadic disease, paraganglioma, and tumor diameters of > 6 cm. Patients with a known genetic mutation or familial pheochromocytoma/paraganglioma were more likely to achieve resection with negative microscopic margins and had improved disease-specific mortality rates. Surgical resection remains the treatment of choice for pheochromocytoma and paraganglioma.

Mortality Associated with Pheochromocytoma: Increased Risk for Additional Tumors

A consecutive series of patients (68 females and 53 males) with pheochromocytoma (PC, n=110) or paraganglioma (PG, n=11) were treated at the Sahlgrenska University Hospital (1950-1997). During the observation period (15+/-6 years) 42 patients died versus 23.6 expected in the general population (P<0.001). There was no surgical mortality. Twenty patients died of cardiovascular disease, 11 of other tumors, and 7 of other diseases, but only 4 of PC/PG. The main causes of death in this regional series were cardiovascular diseases and tumor in a ratio of 1.3 versus 2.0 in the general Swedish population. Analysis of the mortality in all patients with clinically diagnosed PC (n=481, 259 women and 222 men) based on the National Cancer Registry (1957-1997) showed that the number of deaths in this cohort was 196 versus 153.4 expected (P<0.001). These patients had almost four times higher risk of dying of a tumor than did the general population (similar risk for females and males). There was no increased risk for cardiovascular death; in fact, the risk was lower than expected for men (22 vs. 38 expected). A second tumor diagnosed subsequent to PC occurred in 68 versus 31 expected. In men tumors of the liver and biliary tract and central nervous system and in women malignant melanoma and cervix carcinoma were most frequent. The results from the national series thus confirm an increased risk of a second tumor and increased tumor-related mortality in patients with PC.

Malignant Pheochromocytoma in a Population-Based Study: Survival and Clinical Results

One hundred fifty-four consecutive patients with pheochromocytoma (PC, n=137) or paraganglioma (PG, n=17) were treated at our unit. Twenty patients had MEN 2, 15 VRD, and 1 VHL tumors. Twelve had malignant tumors and were classified according to mode of presentation: (1) Distant metastases (n=4); three underwent surgical debulking (with chemotherapy in one); and three had 131I-MIBG therapy. Within 4 years two patients died of tumor progression. (2) Locally advanced disease (n=4), all resected for cure. (3) Malignancy disclosed during follow-up after adrenalectomy with "benign" histopathology (n=4). All patients in groups 2 and 3 developed recurrence 9 (1-17) years after primary surgery; four underwent resection, one remains tumor-free. The others were treated chronically with phenoxybenzamine, combined with 131I-MIBG in one. These eight patients were observed 20 (5-35) years after primary surgery and 11 (1-19) years after recurrence. This series is population-based and may better reflect the natural history of malignant PC/PG than the series from national referral centers. Active surgical treatment and phenoxybenzamine resulted in low tumor-related mortality in groups 2 and 3; five patients died 8-30 years after diagnosis, four of PC/PG (three from group 2 and one from group 3) and one of other causes. We propose tumor uptake studies (MIBG- and octreotide scintigraphy) in patients with nonresectable metastases; to select individual radionuclide therapy data on the expression of CA-transporters/somatostatin receptors may be helpful. To diagnose PC/PG early, screening of adrenal incidentalomas has been suggested. In a regional population-based prospective study, 503 incidentalomas were reported during 18 months, but only one patient with PG was identified.

Malignant Pheochromocytoma

Malignant pheochromocytoma is a rare disease with a high mortality. Surgical resection is the only effective treatment if extensive metastatic disease is not present. However, differentiating between benign and malignant pheochromocytoma is impossible in the absence of locoregional invasion or distant metastasis. This diagnostic dilemma has several drawbacks, including later detection and treatment of recurrence than if malignancy is determined at the original operation. With emerging molecular markers of malignant disease, optimal extent and approach for surgical treatment and appropriate extent of follow up could be established based on specific tumor behavior and the need for additional systemic therapy.

[Surgical management of a preaortic paraganglioma: Report of one case]

Paragangliomas (PG) are rare and often diagnosed in the young adult. One case of retroperitoneal preaortic paraganglioma localised between the celiac trunk and the superior mesenteric artery is reported. The management of paraganglioma involves endocrinologists, geneticists and surgeons but the only potentially curative treatment remains surgical resection. Pathology reports can not always discriminate between benign or malignant tumors. Hereditary in paraganglioma occurs in approximately 25% of cases. Genetic investigation is therefore mandatory in all patients with PG. Since the type of genetic mutation is correlated with tumoral aggressiveness, genetic investigation results should be taken into account when a surgical procedure is planned.

Les phéochromocytomes malins : à propos de trois observations

The authors report three cases of malignant pheochromocytomas. Metastases occurred in the liver in two cases whereas malignancy was suspected in the third case because of recurrence and local invasion. One case was pregnant at diagnosis of pheochromocytoma. Pheochromocytoma was associated to papillary thyroïd carcinoma in another case. The treatment considered was surgery in all cases.

Systemische Therapie maligner Nebennierentumoren

Systemic treatment of advanced-stage adrenal malignancies is most often only palliative. Mitotane alone or in combination with other chemotherapeutic agents such as cisplatin, etoposide, and vincristine are established therapeutic concepts for the treatment of metastatic adrenal cancer. Suramin and gossypol are rarely employed. New therapeutic options are tumor vaccination and treatment with antiangiogenic drugs. Metaiodobenzylguanidine as a radiotherapeutic drug or chemotherapeutic combination therapies that include cyclophosphamide, vincristine, and dacarbazine are applied for systemic treatment of malignant pheochromocytomas.. However, the clinical efficacy of the latter regimen needs further evaluation.

Transcatheter arterial embolization for the treatment of liver metastases in a patient with malignant pheochromocytoma

A 63-year-old male patient was admitted for the treatment of malignant pheochromocytoma with multiple liver metastases. Plasma and urinary levels of catecholamines were elevated. Transcatheter arterial embolization (TAE) with concomitant administration of mitomycin C and gelatin sponge was performed for the treatment of liver metastases. Dose of alpha-1 blocker before TAE was increased to prevent hypertensive crisis during and after TAE. The hepatic metastatic lesion of CT findings was decreased after TAE. Although blood pressure showed a transient hypertension (180/100 mmHg) after every TAE, it returned rapidly to normal. The patient experienced transient abdominal pain, nausea, and loss of appetite after every TAE; however, those symptoms were readily controlled by conventional medications. Slight elevation of liver transaminases was recognized but returned to normal range within 3 weeks. No other major side effects were seen with TAE. While plasma and urinary level of catecholamines were unchanged, plasma chromogranin A (CgA) level was significantly decreased. These results suggest that TAE is a useful treatment for hepatic metastases. Plasma CgA level is a useful marker in the treatment of malignant pheochromocytoma.

Phaeochromocytoma

Phaeochromocytomas are rare neuroendocrine tumours with a highly variable clinical presentation but most commonly presenting with episodes of headaches, sweating, palpitations, and hypertension. The serious and potentially lethal cardiovascular complications of these tumours are due to the potent effects of secreted catecholamines. Biochemical testing for phaeochromocytoma is indicated not only in symptomatic patients, but also in patients with adrenal incidentalomas or identified genetic predispositions (eg, multiple endocrine neoplasia type 2, von Hippel-Lindau syndrome, neurofibromatosis type 1, and mutations of the succinate dehydrogenase genes). Imaging techniques such as CT or MRI and functional ligands such as (123)I-MIBG are used to localise biochemically proven tumours. After the use of appropriate preoperative treatment to block the effects of secreted catecholamines, laparoscopic tumour removal is the preferred procedure. If removal of phaeochromocytoma is timely, prognosis is excellent. However, prognosis is poor in patients with metastases, which especially occur in patients with large, extra-adrenal tumours.

Phaeochromocytoma: current concepts

The discovery of novel mutations in genes encoding succinate dehydrogenase subunits has revealed that familial phaeochromocytomas are much more common than previously thought. Genetic screening should be offered to patients with apparently sporadic phaeochromocytomas and their first-degree relatives. An increasing proportion of phaeochromocytomas present preclinically on genetic testing or as "incidentalomas" on abdominal imaging, rather than with classic symptoms and signs. Clinical suspicion should prompt measurement of plasma levels of free metanephrine or 24-hour urinary catecholamine and metanephrine levels, followed, if positive, by tumour localisation studies. With appropriate perioperative care, surgical management of phaeochromocytomas is safe and effective. Most tumours can be removed laparoscopically.

Long-term outcome of a large series of patients surgically treated for pheochromocytoma

OBJECTIVE

To analyse the morbidity, mortality and long-term outcome in a consecutive series of surgically treated patients with pheochromocytoma (PC), or paraganglioma (PG), from the western region of Sweden between 1950 and 1997.

PATIENTS

All patients (n = 121) who had been hospitalized and treated for PC/PG over 47 years.

DESIGN

Retrospective review of patients with PC/PG regarding presenting symptoms, tumour characteristics, clinical management and long-term outcome after treatment.

SETTING

One referral centre for all patients from the western region of Sweden.

RESULTS

During an observation of 15 +/- 6 years, 42 patients died vs. 23.6 expected in the general population (P < 0.001). There was no intra- or post-operative mortality. Four patients with sporadic disease died of malignant PC and six with hereditary disease of associated neuroectodermal tumours. Five patients died of other malignancies, 20 of cardiovascular disease and seven of other causes. Besides older age at primary surgery, elevated urinary excretion of methoxy-catecholamines was the only observed risk factor for death (P = 0.02). At diagnosis 85% of the patients were hypertensive; one year after surgery more than half were still hypertensive. However, pre- and post-operative hypertension did not influence the risk for death versus controls.

CONCLUSION

Pheochromocytoma/PG can be safely treated by surgery. Death of malignant PC/PG was unusual, but the patients as a group had an increased risk of death. We recommend life-long follow-up of patients treated for PC/PG with screening for recurrent tumour in sporadic cases and for associated tumours in hereditary cases. This strategy would also be helpful in diagnosing cardiovascular disease at an early stage.

Pheochromocytoma and functional paraganglioma syndrome: no longer the 10% tumor

Pheochromocytomas and abdominal paragangliomas are catecholamine-producing tumors of the sympathetic nervous system, while head and neck paragangliomas are non-secreting tumors of parasympathetic origin. Recent developments in clinical and molecular research on these tumor forms have significantly clarified their genetic backgrounds and challenged the view of "pheochromocytoma as the 10% rule tumor." Firstly, a larger proportion of these tumors are today discovered in normotensive patients during imaging carried out for other reasons than suspicion of pheochromocytoma. Secondly, although the differential diagnosis between malignant and benign tumors remains a challenge, the risk of malignancy well exceeds the classical 10% in patients with extra-adrenal disease, and/or carriers of germ-line SDHB mutations. Finally, up to a third of patients carry a germ-line mutation in a gene predisposing to pheochromocytoma and/or paraganglioma. Identification of a constitutional mutation in RET, VHL, SDHD, or SDHB has implications for clinical screening and follow-up for both the patient and for relatives at risk who can be identified by screening for the same mutation. Genetic testing in apparently sporadic cases is therefore regarded as beneficial, especially in patients diagnosed before 50 years of age, and in patients with bilateral, multifocal, malignant and/or extra-adrenal disease.

Recent developments in the therapy of phaeochromocytoma

The basic principles of treatment for phaeochromocytomas and paragangliomas are to block the effects of high catecholamines and make the patient safe for surgical removal of the tumour. The traditional preoperative medical preparation uses the non-selective alpha-adrenoceptor blocker phenoxybenzamine and a beta-adrenoceptor blocker, propranolol. Other agents have been used effectively, including selective alpha-adrenoceptor blockers, doxazosin and prazosin, and calcium channel antagonists. There have been no trial comparing regimens and there is some controversy as to the best regimen. Major advances have been made in laparoscopic and laparoscopic-assisted surgery. Cortical-sparing adrenalectomy has been used in some centres for familial phaeochromocytomas. High-dose [(131)I]-metaiodobenzylguanidine therapy and combined [(131)I]-metaiodobenzylguanidine and chemotherapy are promising new developments for the malignant disease. All patients should be followed indefinitely because the recurrence or malignancy rate is >or= 10% over a prolonged follow up.

Malignant retroperitoneal paraganglioma: case report and review of the literature

Paraganglioma is a rare neuroendocrine neoplasm observed in patients of all ages but it has not been characterized in children. The authors describe a retroperitoneal paraganglioma diagnosed by chance in an 11-year-old boy. Many aspects of retroperitoneal paraganglioma are still under investigation. The treatment of choice is radical resection. Surgery may be possible following chemotherapeutic debulking with cyclophosphamide, vincristine, and dacarbazine. 131I-MIBG radiotherapy has proved increasingly useful in reducing the pain associated with disseminated disease and also in facilitating surgical resection in cases that appear inoperable. Conventional radiotherapy is purely palliative and used to reduce the pain of bone metastases.

Predictive value of preoperative transthoracic echocardiography in patients undergoing adrenalectomy for pheochromocytoma

BACKGROUND

Adrenalectomy for pheochromocytoma is a life-threatening procedure. Few echocardiographic assessments have been reported in patients undergoing adrenalectomy for pheochromocytoma.

METHODS

Sixty-three consecutive patients undergoing adrenalectomy for pheochromocytoma underwent routine preoperative M-mode and two-dimensional echocardiography, and Doppler examination. Abnormal echocardiographic findings were defined as left ventricular dilatation or dysfunction (left ventricular percentage fractional shortening < 30%), and/or left ventricular wall motion abnormalities, and/or left ventricular hypertrophy (left ventricular mass index > 110 g m(-2) in women and >134 g m(-2) in men) and/or valvular abnormalities. Physical characteristics, daily urinary metanephrine and normetanephrine excretions, preoperative functional limitation, pre-existing congestive heart failure, type and duration of surgery, and haemodynamic instability in the intra and postoperative periods were compared in patients with normal and abnormal echocardiographic findings.

RESULTS

Twenty-four out of 63 patients were found to have abnormal preoperative echocardiography. There was no difference between patients with normal and abnormal preoperative echocardiography as regards to the investigated criteria, except for pre-existing self-reported functional limitation and chest pain suggesting coronary artery disease.

CONCLUSIONS

The relevance of routine preoperative echocardiographic examination in patients scheduled for adrenalectomy for pheochromocytoma, who have no cardiac symptoms or clinical evidence of cardiac involvement, is questionable.

Pheochromocytoma and functional paraganglioma

PURPOSE

Pheochromocytomas and paragangliomas are rare tumors of chromaffin cell origin. Their identification is likely increasing owing to the increased use of radiographic images detecting incidental adrenal masses.

RECENT FINDINGS

The pathophysiology of hypertension induced by the release of catecholamines and newly discovered peptides has been shown to be more complex than the concept of episodic catecholamine release.

SUMMARY

This review looks at the most recent advances in the physiology and molecular basis of these tumors.