Malignant pheochromocytoma: clinical course and treatment

The North American Neuroendocrine Tumor Society Consensus Guidelines for Surveillance and Management of Metastatic and/or Unresectable Pheochromocytoma and Paraganglioma

ABSTRACT

This manuscript is the result of the North American Neuroendocrine Tumor Society consensus conference on the medical management and surveillance of metastatic and unresectable pheochromocytoma and paraganglioma held on October 2 and 3, 2019. The panelists consisted of endocrinologists, medical oncologists, surgeons, radiologists/nuclear medicine physicians, nephrologists, pathologists, and radiation oncologists. The panelists performed a literature review on a series of questions regarding the medical management of metastatic and unresectable pheochromocytoma and paraganglioma as well as questions regarding surveillance after resection. The panelists voted on controversial topics, and final recommendations were sent to all panel members for final approval.

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.

Predictive characteristics of malignant pheochromocytoma

Purpose

The prognosis of patients with malignant pheochromocytoma is poor, but the predictive factors are not well understood. We aimed to identify the clinical characteristics predictive of malignancy after initial surgical removal in patients with pheochromocytoma.

Materials and Methods

We retrospectively reviewed the records of 152 patients diagnosed with pheochromocytoma, including 5 (3.3%) with metastasis at the time of the initial surgical excision and 12 (7.9%) who developed metastasis during follow-up. To determine the factors predictive of malignancy, we compared clinical, radiographical, and urinary chemical findings between patients with benign and malignant disease. Mean follow-up was 41.5 months (range, 0.9-298 months) after surgery.

Results

Malignant tumors were significantly larger than benign tumors (11.1±4.0 cm vs. 6.2±3.4 cm, p<0.001), and postoperative persistence of arterial hypertension was more frequent after removal of malignant than benign tumors (p=0.001). Among the 147 patients without metastatic disease at diagnosis, those who developed metastasis had significantly lower concentrations of urinary catecholamine metabolites per unit of tumor, including vanillylmandelic acid (1.2 vs. 3.7 mg/day/cm, p=0.049), epinephrine (4.5 vs. 168.9 µg/day/cm, p=0.008), and norepinephrine (13.1 vs. 121.8 mg/day/cm, p<0.001). The overall 5-year metastasis-free survival rate was 84.4% and was significantly higher in patients with smaller tumors (≤5.5 vs. >5.5 cm; 90.6% vs. 81.2%, p=0.025) and higher 24-hour secretion of vanillylmandelic acid (>2.1 vs. ≤2.1 mg/day/cm; 94.9% vs. 70.9%, p=0.019).

Conclusions

Large tumor size (>5.5 cm) and minimally elevated 24-hour urinary vanillylmandelic acid (≤2.1 mg/day/cm) were significantly associated with a higher probability of a malignant pheochromocytoma portending a lower metastasis-free survival and mandating more rigorous follow-up after surgery.

Malignant pheochromocytoma with liver metastasis treated by transcatheter arterial chemo-embolization (TACE)

Multiple liver metastatic lesions were shown by computed tomography and scintigraphy with 123I- metaiodobenzylguanidine (MIBG) in a 76-year-old woman 2 years after resection of a pheochromocytoma of the right adrenal gland. Transcatheter arterial chemo-embolization (TACE) was performed for the liver metastasis, with blood pressure strictly controlled by administration of doxazosin and phentolamine for the prevention of hypertensive crisis after TACE. There were no severe adverse events associated with the treatment, and the number and size of the lesions were decreased. TACE with strict blood pressure control was an effective and safe therapy for multiple liver metastatic lesions related to malignant pheochromocytoma.

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.

Review: Should patients with apparently sporadic pheochromocytomas or paragangliomas be screened for hereditary syndromes?

CONTEXT

The recent identification of germline mutations of the mitochondrial complex II genes in variants of paraganglioma/pheochromocytoma syndrome has enlarged the number of known causative genes for hereditary pheochromocytoma. A question confronting clinicians is whether they should screen patients with apparently sporadic pheochromocytomas for unsuspected germline mutations of some or all of the seven genes known to cause hereditary paraganglioma or pheochromocytoma (NF1, VHL, RET, MEN1, SDHD, SDHC, and SDHB). A positive answer was suggested by a report that placed the estimate of hereditary disease in apparently sporadic pheochromocytoma as high as 24%.

EVIDENCE ACQUISITION

We applied clinically useful criteria to a review of the literature, defining cases of apparently sporadic pheochromocytoma as those without a suspicious personal or family history, with a focal, unilateral pheochromocytoma, and presenting at age less than 50 yr.

EVIDENCE SYNTHESIS

We reduced the overall estimate of unsuspected hereditary pheochromocytoma patients with apparently sporadic pheochromocytoma to approximately 17%. Mutations in only three genes (VHL, SDHB, and SDHD) accounted for almost this entire minority, and unsuspected RET mutation was rare. Costs, coverage by insurance, the potential effect on insurability, and deficient information for populations outside of referral centers should be considered before recommending genetic testing in patients with apparently sporadic presentations of pheochromocytomas.

CONCLUSION

We recommend genetic testing for patients with an apparently sporadic pheochromocytoma under the age of 20 yr with family history or features suggestive of hereditary pheochromocytoma or for patients with sympathetic paragangliomas. For individuals who do not meet these criteria, genetic testing is optional.

Primary meningeal pheochromocytoma: case report

OBJECTIVE AND IMPORTANCE

Intracranial pheochromocytomas are extremely rare tumors. Reported cases include metastatic tumors without known cases of primary pheochromocytomas.

CLINICAL PRESENTATION

A female patient with a history of a surgically treated adrenal pheochromocytoma presented 23 years later with headache, nausea and blood hypertension. A head CT scan demonstrated a right temporoparietal meningeal heterogeneous lesion with a surrounding hyperdense ring. No other lesions were disclosed.

INTERVENTION

The lesion developed in the inner and outer surface of the dura without brain infiltration and it was totally resected. The patient is free of disease 6 years after brain surgery.

CONCLUSION

To our knowledge this is the first reported case of a primary meningeal pheochromocytoma.

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.

Malignant nonfunctioning pheochromocytoma occurring in a mixed multiple endocrine neoplasia syndrome

OBJECTIVE

To present the first documented case of malignant nonfunctioning pheochromocytoma occurring in a mixed multiple endocrine neoplasia (MEN) syndrome.

METHODS

We describe the personal and family history of a 34-year-old man with headaches, increased serum prolactin levels, and hyperparathyroidism and review the details of his clinical course and treatment.

RESULTS

After diagnosis of a prolactinoma, bromocriptine therapy was implemented but eventually discontinued by the patient when severe headaches recurred. A transsphenoidal resection of a prolactinoma was performed; the patient continued to have abnormally high serum prolactin levels. Subsequent left lower flank pain prompted an exploratory laparotomy, and a left nephroad-renalectomy was performed. Pathologic examination disclosed a 1-cm tumor, consistent with malignant pheochromocytoma. Electron microscopy demonstrated neurosecretory granules. A hypercoagulable state complicated the course postoperatively. Despite chemotherapy, extensive metastatic disease ensued, and the patient died.

CONCLUSION

Although pheochromocytomas are usually associated with MEN type IIA and type IIB, this patient had a malignant pheochromocytoma, without the usual clinical and biochemical manifestations, in the setting of MEN type I.

Laparoscopic adrenalectomy for malignancy

Laparoscopic adrenalectomy for primary malignancies and tumors metastatic to the adrenal is controversial. Most studies demonstrate that results of laparoscopic adrenalectomy for malignant lesions are similar to those of open adrenalectomy, without its morbidity. The results of laparoscopic adrenalectomy for tumor metastases suggest that it may benefit patients who have a metachronous metastasis from any of a variety of primary tumors. Selective laparoscopic adrenalectomy for potentially malignant tumors requires seeking signs of local invasion, lymphadenopathy, or distant metastasis; there are no other reliable preoperative criteria of malignancy. Diagnostic laparoscopy may be useful, and in some cases, may establish a diagnosis. Laparoscopic adrenalectomy should be cautiously performed, with the goals of achieving complete tumor resection without disruption of the adrenal capsule.

High-dose 131I-metaiodobenzylguanidine therapy for 12 patients with malignant pheochromocytoma

BACKGROUND

131I-Metaiodobenzylguanidine (131I-MIBG) can be used systemically to treat malignant pheochromocytoma. To improve outcome, the authors used higher levels of activity of 131I-MIBG than previously reported. The authors reported the response rates and toxicity levels in patients with malignant pheochromocytoma or paraganglioma who were treated with high-dose 131I-MIBG.

METHODS

Following debulking surgery and stem cell harvest, 12 patients with malignant pheochromocytoma or paraganglioma were treated with 131I-MIBG. Five had received previous external beam radiation and/or chemotherapy. The median single treatment dose was 800 mCi (37 gigabecquerels; range, 386-866 mCi) or 11.5 mCi/kg (range, 5.6-18.3 mCi/kg). The median cumulative dose was 1015 mCi (range, 386-1690 mCi).

RESULTS

Three patients had a complete response, two of whom had soft tissue and skeletal metastases. Their median follow-up was 45 months (range, 23-101 months). Seven patients had a partial response (PR), with a median follow-up 43 months (range, 6-47 months). Two patients without a response died with progressive disease (PD) and 2 patients with an initial PR died of PD at 13 and 11 months, respectively. Grade 3 thrombocytopenia occurred after 79% (15 of 19) of treatments had been administered. Grade 3 and 4 neutropenia followed 53% (10 of 19) and 19% (4 of 19) of treatments, respectively. One patient required stem cell infusion, and one developed primary ovarian failure.

CONCLUSIONS

The single and cumulative doses of 131I-MIBG were approximately 2-3.5 times higher than those used at other centers. Unlike previous reports, two patients with both skeletal and soft tissue metastases had a complete response. Hematologic toxicity was significant but tolerable. High-dose 131I-MIBG may lead to long-term survival in patients with malignant pheochromocytoma.

Treatment of metastatic carcinoid tumours, phaeochromocytoma, paraganglioma and medullary carcinoma of the thyroid with (131)I-meta-iodobenzylguanidine [(131)I-mIBG]

OBJECTIVE

Meta-iodo-benzyl-guanidine labelled with 131-iodine [(131)I-mIBG] has been used extensively for imaging tumours originating from the neural crest but experience with its therapeutic use is limited, particularly for non-catecholamine secreting tumours. In order to assess the therapeutic response and potential adverse effects of the therapeutic administration of (131)I-mIBG, we have reviewed all patients who had received this form of treatment in our department.

DESIGN

Retrospective analysis of the case notes of patients with neuroendocrine tumours who received treatment with (131)I-mIBG and were followed-up according to a defined protocol in a given time frame.

PATIENTS

Thirty-seven patients (18 with metastatic carcinoid tumours, 8 metastatic phaeochromocytoma, 7 metastatic paraganglioma and 4 metastatic medullary carcinoma of the thyroid) treated with (131)I-mIBG over a 15-year period were included in this analysis.

MEASUREMENTS

The symptomatic, hormonal and tumoural responses before and after (131)I-mIBG therapy over a median follow-up duration of 32 months (range 5-180 months) were recorded. Of the 37 patients (22 males; median age 51 years, range 18-81 years), 15 were treated with (131)I-mIBG alone whereas the other 22 received additional therapy.

RESULTS

A total of 116 therapeutic (131)I-mIBG doses were administered [mean cumulative dose 592 mCi (21.9 GBq); range 200-1592 mCi (7.4-58.9 GBq)]. None of the patients showed a complete tumour response. However, 82% of patients treated with (131)I-mIBG alone and 84% who received additional therapy showed stable disease over the period of follow-up. Overall survival during the period of the study was 71%. The overall 5-year survival rate was 85% (95% confidence interval, 72-99%) for all patients and 78% (95% confidence interval, 55-100%) for the carcinoid group alone, according to Kaplan-Meier analysis. Symptomatic control was achieved in all the patients treated with (131)I-mIBG alone, and in 72% of those receiving additional therapy. Hormonal control was noted in 50% and 57% of patients, respectively. (131)I-mIBG therapy was safe and well tolerated. Serious side-effects necessitating the termination of (131)I-mIBG therapy were seen in only 2 of our patients.

CONCLUSIONS

(131)I-mIBG therapy produces symptomatic and hormonal improvement and moderate tumour regression/stabilization in patients with metastatic neuroendocrine tumours with minimal adverse effects. It may be a valuable alternative or additional therapeutic option to the currently available conventional treatment modalities.

Multicentric pheochromocytoma and involvement of the inferior vena cava

CONTEXT

Extension of pheochromocytomas to the inferior vena cava is rare. Multicentric tumors are rare as well, being present in up to 10% of cases. Surgery is the treatment of choice because of the long-term survival free of disease.

DESIGN

Case report.

CASE REPORT

We report on a case of right adrenal pheochromocytoma with extension to the supra-diaphragmatic vena cava, which underwent surgical excision through thoracophrenic laparotomy without the need for cardiopulmonary bypass. In a 6-year follow-up, another pheochromocytoma was found in the infra-renal Zuckerkandl's organ. Complete surgical excision of the tumor was performed by a median laparotomy and complete retroperitoneal dissection. In both cases, the total removal of the pheochromocytoma has been guaranteed by having margins free of tumor and a normal post-operative level of catecholamines. The pathological study revealed a malignant pheochromocytoma with margins free of neoplasia in both specimens.

Hypertension in patients with pheochromocytoma

Adrenal-dependent hypertension syndromes are uncommon forms of hypertension. They include primary aldosteronism, pheochromocytoma, Cushing"s syndrome, and congenital adrenal hyperplasia. Pheochromocytomas are the cause of hypertension in 0.1% to 0.2% of hypertensive patients. Excess catecholamine release and other neural and humoral mechanisms contribute to the pathophysiology of hypertension. Patients with pheochromocytomas have a potentially curable cause of endocrine hypertension and, if undetected, pheochromocytomas confer a high risk for morbidity and mortality, especially during surgical procedures and pregnancy. All patients with incidental adrenal tumors, regardless of tumor size, should be biochemically screened for pheochromocytoma (especially before resection or needle biopsy) to avoid precipitation of a lethal hypertensive crisis.

The treatment of malignant pheochromocytoma with iodine-131 metaiodobenzylguanidine (131I-MIBG): a comprehensive review of 116 reported patients

Iodine-131 metaiodobenzylguanidine (131I-MIBG), a radiopharmaceutical agent used for scintigraphic localization of pheochromocytomas, has been employed to treat malignant pheochromocytomas since 1983 in a few specialized centers around the world. We review our clinical experience together with the published experience of 23 other centers in 10 countries, regarding the use of 1311-MIBG for treating patients with malignant adrenal pheochromocytomas or extra-adrenal paragangliomas. There were a total of 116 evaluable patients: 3 were from our current report and another 113 were reported in the literature from 1983 to 1996. A majority of the patients were selected for treatment based upon positive tracer uptake studies. The cumulative dose of 131I-MIBG administered ranged from 96 to 2,322 mCi (3.6 to 85.9 GBq), with a mean (+/-SD) of 490+/-350 mCi (18.1+/-13.0 GBq). The subjects received a mean single therapy dose of 158 mCi (5.8 GBq) and the number of doses administered ranged from 1 to 11, with a mean of 3.3+/-2.2 doses. Initial symptomatic improvement was achieved in 76% of patients, tumor responses in 30%, and hormonal responses in 45%. Five patients had complete tumor and hormonal responses, ranging from 16 to 58 months, which were sustained at the time of reporting. Patients with metastases to soft tissue had more favorable responses to treatment than those with metastases to bone. No difference was noted in the age between the responders and non-responders. Adverse effects, recorded in 41% of the treated patients, were generally mild except for one fatality from bone marrow aplasia. Among 89 patients with follow-up data, 45% of the responders had relapsed with recurrent or progressive disease after a mean interval of 29.3+/-31.1 months (median 19 months). Of patients with an initial response to 1311-MIBG, death was reported in 33% after a mean of 23.2+/-8.1 months (median 22 months) following treatment. Of non-responders, death was reported in 45% after a mean of 14.3+/-8.3 months (median 13 months). In conclusion, this review suggests that 131I-MIBG therapy may be a useful palliative adjunct in selected patients with malignant pheochromocytoma or paraganglioma. Although controlled studies are lacking, our review raises the hope that this therapeutic modality may prolong survival with an occasional sustained complete remission or possible cure.

[Extra-adrenal gland pheochromocytoma. Apropos of 3 cases and review of the literature]

The authors report three new cases of ectopic pheochromocytoma: latero-aortic, bladder and near the kidney. From the review of the literature, they propose a diagnostic and therapeutic strategy for the management of ectopic localisation of pheochromocytoma.

Radionuclide therapy of malignant pheochromocytoma with 131I-MIBG

Three patients with malignant pheochromocytoma were treated with intravenous infusion of 131I-MIBG. The dose per therapy ranged from 2.33 to 4.03 GBq. The repeated therapies were performed at intervals of 6, 11, 10 and 13 months in the first patient, 17 and 11 months in the second patient and 9 months in the third patient. Lumbago disappeared but little objective improvement was achieved in the first patient. The second patient exhibited a gradual decrease in catecholamine values with no change in tumor size. Remarkable decreases in tumor size and catecholamine values were observed in the third patient. No side effect was observed in any patient. The radiation dose absorbed by the main tumor was the highest at the first therapy and decreased with the number of therapies: 42, 26, 19, x and 9.0 Gy in the first patient, 63, 20 and 8.8 Gy in the second patient, and 81 and 40 Gy in the third patient. This was due mainly to the decrease in % uptake by the tumor of the 131I-MIBG dose administered. Therefore the increase in the dose of 131I-MIBG administered at the first therapy and/or shorter interval therapies seems to be important to obtain more therapeutic effects on malignant pheochromocytoma.

Malignant pheochromocytoma: clinical, biological, histologic and therapeutic data in a series of 20 patients with distant metastases

Twenty patients, 16 males and 4 females, aged 11-76 yr, were treated for a metastatic pheochromocytoma at our institution between 1985 and 1990. A neurofibromatosis was associated in 4. Thirteen patients had a unilateral adrenal tumor, 3 had an extraadrenal retroperitoneal tumor, 2 had a bilateral adrenal pheochromocytoma, one had a unilateral tumor with a contralateral medullary hyperplasia and one an adrenal and an extraadrenal pheochromocytoma. Metastases occurred in all patients, at presentation in 11, 10 to 30 months later in 7, and 9 and 28 yr later, respectively in two. Histology did not afford conclusive evidence for malignancy. Catecholamine hyperproduction was present in all, predominantly affecting norepinephrine. Neuron Specific Enolase level was elevated in 11, Neuro-Peptide Y level in 9 and procalcitonin level in 11/18. High dopamine, methoxytyramine and homovanillic acid excretion levels seemed to correlate with large tumors or terminal stage. MIBG uptake was found in 16 after a diagnostic dose and in 1 only after a therapeutic dose. Surgery was performed on primary tumor in 18 and on distant metastase in 10. Iodine-131 MIBG therapy was performed in 11, among whom 9 were evaluable. Cumulative activity ranged from 100 to 711 mCi, in 1 to 6 courses. Symptomatic improvement occurred in 5 patients, stabilization was observed in 3 and tumor partial response in two, which lasted for 28 and 9 months, respectively terminating in a rapidly progressing disease with bone marrow involvement. Moderate myelosuppression occurred in 4 patients. Chemotherapy gave no response in 7 evaluable patients. Fourteen patients died with a median survival of 16 months from diagnosis of metastases (range 3-60). Response to therapy was poor and warrants further cooperative trials.

A case of pheochromocytoma with severe paralytic ileus

We report herein a rare case of a 26 year old woman with pheochromocytoma complicated by paralytic ileus. She presented with remarkable abdominal distension and respiratory difficulty but was effectively treated by surgical removal of the tumor with preoperative and operative management using alpha and beta adrenergic blocking agents. An excessive and persistent catecholamine production from large tumors or massive metastases characterizes this rare complication, and a review of the English and Japanese literature is given following this report.

Multiple venous sampling for catecholamine assay in the diagnosis of malignant pheochromocytoma

Malignant pheochromocytoma is a rare cause of hypertension and still has a high mortality rate. The most accurate way to localize a malignant pheochromocytoma is by a combination of scans, both CT and scintigraphy. Selective sampling of venous blood from multiple sites for plasma catecholamine levels is a safe and reliable technique and may be used successfully in some patients. A case is presented where venous sampling proved to be useful in preoperatively localizing a malignant pheochromocytoma and its metastatic lesions which both CT and ultrasound had failed to demonstrate.

Late recurrence of benign pheochromocytomas: the necessity for long-term follow-up

Two patients who had removal of seemingly benign pheochromocytomas had recurrences 10 and 14 years later despite normal catecholamine excretion for 7 and 9 years postoperatively. The first patient returned with a myocardial infarction and an apparently solitary recurrence; the second patient with a stroke and metastatic disease. Both patients had recurrence of hypertension and increased catecholamine excretion. They were given phenoxybenzamine and are doing satisfactorily 7 and 9 years after their recurrences. Such patients should be followed after surgery for 15 or more years for early detection of recurrences. Prompt therapy should reduce the risk of undesirable complications.

Pheochromocytoma presenting as musculoskeletal pain from bone metastases

Six patients presented with musculoskeletal pain resulting from destructive bone lesions. These patients were ultimately shown to have metastatic pheochromocytoma. None of the cases exhibited typical symptoms of metastatic pheochromocytoma, nor was it suspected at the time of presentation. In three patients, hypertension caused pheochromocytoma to be considered as a diagnosis. The three remaining patients, all of whom had documented hypertension in the past, underwent bone biopsy. Two of these patients became markedly hypertensive in the postoperative period. Malignant pheochromocytoma may present with metastatic skeletal disease in some patients in whom the presence of hypertension as well as a carefully elicited history may suggest the diagnosis. In such patients, the possibility of pheochromocytoma should be taken into account, as biopsy may trigger a hypertensive crisis in patients not under adrenergic blockade.

Recurrent pheochromocytoma: intrarenal and pulmonary spread

A case of intrarenal malignant pheochromocytoma, closely resembling hypernephroma radiologically, is presented. This tumor with 2 other pulmonary masses, recurred 12 years after ablation of an adrenal pheochromocytoma and extended into the inferior vena cava.

Malignant phaeochromocytoma

Malignant phaeochromocytoma is a rare tumour and experience in its management is therefore limited. Five patients are discussed in whom the development of metastases was associated with rapidly progressive disease.

Malignant phaeochromocytoma: clinical, biochemical and scintigraphic characterization

We have evaluated thirty patients with malignant metastatic phaeochromocytoma with regard to clinical features, indices of catecholamine secretion, histology of lesions and a number of imaging procedures including scintigraphy with the recently developed sympathetic tissue-seeking radiopharmaceutical 131I-metaiodobenzylguanidine (131I-MIBG). The primary tumour was extra-adrenal in 13 cases. The commonest site of metastases was the axial skeleton (20 cases), followed by liver (four cases), lymph nodes (four cases), peritoneum (two cases) and lung (three cases). The malignancies were indolent, the mean time following the initial diagnosis was 9.18 years (range 0 to 33 years) and the mean duration of known metastases 3.71 years (range 0 to 18 years). There was a wide range of abnormalities in plasma and urinary catecholamines which did not correlate with the extent of tumour spread, histological pattern (mitotic index, Zellballen pattern, capsular or vascular invasion pleomorphism or necrosis) or 131I-MIBG uptake by tumour deposits. 131I-MIBG scintigraphy was found to be a useful technique for determining the extent of metastatic disease in most cases (26 of 30) and in some patients (16 of 30) was more sensitive than other radiological procedures. No false positive scans were encountered.

Primary vesical pheochromocytoma

Pheochromocytoma of the urinary bladder is a rare neoplasm that often occurs with the unique symptom complex of micturitional attacks due to increased catecholamine secretion during detrusor activity. Analysis of 3 of our patients is added to a discussion of 97 cases reported in the world literature. Therapeutic decision is complicated by the absence of unequivocal histologic criteria of malignancy for these tumors. Future perspectives in determining the malignant potential of pheochromocytoma are presented and our treatment plan elaborated.

CT localization of occult secretory tumors in children

Three seemingly occult secretory tumors in children (pheochromocytoma, ganglioneuroblastoma and islet cell carcinoma) were localized within the abdomen by computed tomography after other diagnostic imaging procedures had failed. The superb density resolution and tomographic formating of CT images make CT uniquely suited for the demonstration of small abdominal lesions. CT is recommended as a primary imaging modality for secretory tumors in children.

Malignant Pheochromocytomas: Report of 4 Cases

Four cases of pheochromocytomas are reported: 3 cases of malignant pheochromocytomas of the adrenal glands and 1 case of pheochromocytoma, diagnosed on the basis of clinical and biologic signs, whose site and malignant character were not demonstrated. A rare association of pheochromocytoma and stenosis of the renal artery, recorded for one of the cases, is discussed.

Malignant pheochromocytoma of the bladder

A review of malignant pheochromocytoma of the bladder is presented with an illustrative case, emphasizing the importance of preoperative localization and an extirpative surgical approach for such patients. Since histologic criteria of malignancy in phoechromocytomas have not yet been established all of these patiets warrant a thorough intraoperative search and long-term postoperative followup for possible metastases.