Malignant phaeochromocytoma: clinical, biochemical and scintigraphic characterization

Lesion-based indicators predict long-term outcomes of pheochromocytoma and paraganglioma- SIZEPASS

Aim

We seek a simple and reliable tool to predict malignant behavior of pheochromocytoma and paraganglioma (PPGL).

Methods

This single-center prospective cohort study assessed size of primary PPGLs on preoperative cross-sectional imaging and prospectively scored specimens using the Pheochromocytoma of the Adrenal Gland Scaled Score (PASS). Multiplication of PASS points with maximum lesion diameter (in mm) yielded the SIZEPASS criterion. Local recurrence, metastasis or death from disease were surrogates defining malignancy.

Results

76 consecutive PPGL patients, whereof 58 with pheochromocytoma and 51 female, were diagnosed at a mean age of 52.0 ± 15.2 years. 11 lesions (14.5%) exhibited malignant features at a median follow-up (FU) of 49 months (range 4-172 mo). Median FU of the remaining cohort was 139 months (range 120-226 mo). SIZEPASS classified malignancy with an area under the curve (AUC) of 0.97 (95%CI 0.93-1.01; p<0.0001). Across PPGL, SIZEPASS >1000 outperformed all known predictors of malignancy, with sensitivity 91%, specificity 94%, and accuracy 93%, and an odds ratio of 72 fold (95%CI 9-571; P<0.001). It retained an accuracy >90% in cohorts defined by location (adrenal, extra-adrenal) or mutation status.

Conclusions

The SIZEPASS>1000 criterion is a lesion-based, clinically available, simple and effective tool to predict malignant behavior of PPGLs independently of age, sex, location or mutation status.

Quantitative analysis of normal and pathologic adrenal glands with 18F-FDOPA PET/CT: focus on pheochromocytomas

INTRODUCTION

Many studies have reported the high performance of 6-fluorine-18-fluorodihydroxyphenilalanine (F-FDOPA) PET/CT in the diagnosis of pheochromocytomas but nobody seems to have investigated physiological and pathological adrenal glands from a quantitative point of view. The purpose of the present study was to assess the quantitative F-FDOPA uptake of normal and pathologic adrenal glands and to establish thresholds to characterize pheochromocytomas. We were especially interested in characterizing the remaining adrenal glands captation after an adrenalectomy.

PATIENTS AND METHODS

We reviewed 112 F-FDOPA PET/CT scans taken for different indications. A total of 212 adrenal glands, of which 17 were pheochromocytomas, were analyzed on the basis of their functional and morphological features. The final diagnosis was based on histologic proof when available (six pheochromocytomas) or after synthesis of clinical, biological, morphological, and functional results. Maximum standardized uptake value (SUVmax), mediastinum, and liver ratios in case of pheochromocytomas, adenomas, and solitary adrenal glands were determined and compared with those of healthy glands. Receiver operating characteristic curves were determined and areas under the curve were compared for different cutoffs of each index.

RESULTS

Pheochromocytomas demonstrated a higher F-FDOPA uptake compared with normal adrenal glands (mean SUVmax: 7.5, SD 4.0, range: 3.5-20.0 vs. mean SUVmax: 2.6, SD: 0.8, range: 1.0-6.9) (P<0.0001). An SUVmax threshold of 4.2 has a sensitivity and specificity of 94 and 98%, respectively. The areas under the curve were 0.988, 0.991, and 0.987 for an SUVmax of 4.2, a mediastinum ratio of 3.0, and a liver ratio of 1.7, respectively. A large number of nonsecreting pheochromocytomas were noticed. On the basis of the SUVmax no statistically significant difference was found between secreting (SUVmax: 8.9, SD: 5.3) and nonsecreting pheochromocytomas (SUVmax: 5.1, SD: 0.9) (P=0.141). After unilateral adrenalectomy, solitary glands presented no increased uptake compared with healthy adrenal glands. An unexpected lower captation was also observed (SUVmax: 2.0, P=0.047).

CONCLUSION

We confirm the high affinity of F-FDOPA for secreting or nonsecreting pheochromocytoma. Indeed within a series of various adrenal glands, only these tumors presented a significant increased uptake compared with normal adrenal glands. Because of a high rate of nonhypersecreting lesions, F-FDOPA can act as a surrogate to biological assays. After an adrenalectomy, the remaining glands did not demonstrate compensatory accumulation of F-FDOPA. To our knowledge this last point has never been addressed.

I-131 Metaiodobenzylguanidine Therapy of Pheochromocytoma and Paraganglioma

Pheochromocytomas and paragangliomas are rare tumors arising from chromaffin cells. Available therapeutic modalities consist of chemotherapy, tyrosine kinase inhibitors, and I-131 metaiodobenzylguanidine (MIBG). I-131 MIBG is taken up via specific receptors and localizes into many but not all pheochromocytomas and paragangliomas. Because these tumors are rare, most therapy studies are retrospective presentations of clinical experience. Numerous retrospective studies and a few prospective studies have shown favorable responses in this disease, including symptomatic, biochemical, and objective responses. In this report, we review the experience of using I-131 MIBG therapy for targeting pheochromocytoma and paragangliomas.

No evidence for increased mortality in SDHD variant carriers compared with the general population

Germline variants in subunit D of the succinate dehydrogenase gene (SDHD variants) are associated with an increased risk of developing paragangliomas. The aim of this study was to compare mortality rates and survival in a Dutch cohort of SDHD variant carriers with those in the general population. The study was conducted at the Leiden University Medical Center, a tertiary referral center for patients with paragangliomas. Included subjects all tested positive for SDHD variants before 1 July 2012 and visited the departments of Otorhinolaryngology or Endocrinology at least once or had a diagnosed paraganglioma and a SDHD variant-positive family history. Clinical data were retrieved from medical records, information on mortality was obtained from the Municipal Personal Records Database, and mortality rates for the Dutch population were obtained from the Dutch Central Bureau of Statistics, stratified by sex, age and date. SDHD variant carriers were followed from the date of first SDHD variant-related contact until death, emigration or 12 December 2012 and the standardized mortality ratio (SMR) was calculated. Two-hundred and seventy-five SDHD variant carriers were included in the study, of which 80% carried the c.274G>T, p.(Asp92Tyr) variant, had a mean duration of follow-up of 7.6 years, yielding 2242 person-years of observation for analysis. There were 18 deaths in the SDHD variant carrier group; two were paraganglioma related. The SMR for the whole cohort was 1.07 (95% confidence interval 0.67-1.73). In conclusion, mortality in SDHD variant carriers is not substantially increased. Additional studies are required to confirm these findings.

Iodine-131 meta-iodobezylguanidine single photon emission computed tomography/computerized tomography in diagnosis of neuro-endocrine tumors

Metaiodobenzyl guanidine (MIBG) is a derivative of guanethidine and acts as an analogue of nor-epinephrine and is widely used in the imaging of tumors of neuro-endocrine origin. Iodine-123 MIBG has ideal imaging characteristics but is expensive with limited availability. Iodine-131 MIBG is widely used in India and is cheap. Hybrid single photon emission computed tomography (SPECT)/computerized tomography (CT) allows for anatomico-functional imaging and is being tried in MIBG studies. However, the experience with I-131 MIBG is limited. We present a pictorial assay of I-131 MIBG SPECT/CT findings in various MIBG avid tumors.

Regression and local control rates after radiotherapy for jugulotympanic paragangliomas: systematic review and meta-analysis

The primary treatment goal of radiotherapy for paragangliomas of the head and neck region (HNPGLs) is local control of the tumor, i.e. stabilization of tumor volume. Interestingly, regression of tumor volume has also been reported. Up to the present, no meta-analysis has been performed giving an overview of regression rates after radiotherapy in HNPGLs. The main objective was to perform a systematic review and meta-analysis to assess regression of tumor volume in HNPGL-patients after radiotherapy. A second outcome was local tumor control. Design of the study is systematic review and meta-analysis. PubMed, EMBASE, Web of Science, COCHRANE and Academic Search Premier and references of key articles were searched in March 2012 to identify potentially relevant studies. Considering the indolent course of HNPGLs, only studies with ≥ 12 months follow-up were eligible. Main outcomes were the pooled proportions of regression and local control after radiotherapy as initial, combined (i.e. directly post-operatively or post-embolization) or salvage treatment (i.e. after initial treatment has failed) for HNPGLs. A meta-analysis was performed with an exact likelihood approach using a logistic regression with a random effect at the study level. Pooled proportions with 95% confidence intervals (CI) were reported. Fifteen studies were included, concerning a total of 283 jugulotympanic HNPGLs in 276 patients. Pooled regression proportions for initial, combined and salvage treatment were respectively 21%, 33% and 52% in radiosurgery studies and 4%, 0% and 64% in external beam radiotherapy studies. Pooled local control proportions for radiotherapy as initial, combined and salvage treatment ranged from 79% to 100%. Radiotherapy for jugulotympanic paragangliomas results in excellent local tumor control and therefore is a valuable treatment for these types of tumors. The effects of radiotherapy on regression of tumor volume remain ambiguous, although the data suggest that regression can be achieved at least in some patients. More research is needed to identify predictors for treatment success.

Multiple endocrine neoplasia type 2A

Multiple endocrine neoplasia type 2A (MEN 2A) is an autosomal dominant inherited cancer syndrome that expresses nonendocrine and endocrine tumors. Here, we describe a 42-year-old man with an initial presentation of low back pain and hypertension. Clinical assessments revealed pheochromocytoma, medullary thyroid carcinoma with bone metastasis, and parathyroid hyperplasia. MEN 2A was diagnosed, and a family history of pheochromocytoma was traced. Surgical resection of the pheochromocytoma of the adrenal gland resulted in a cure of the patient's hypertension. He received systemic chemotherapy with the "MAID" regimen (mesna, doxorubicin, ifosfamide, and dacarbazine) over three cycles of 3 weeks each, and showed a partial response.

Adrenal cortical tumors, pheochromocytomas and paragangliomas

Distinguishing adrenal cortical adenomas from carcinomas may be a difficult diagnostic problem. The criteria of Weiss are very useful because of their reliance on histologic features. From a practical perspective, the most useful criteria to separate adenomas from carcinomas include tumor size, presence of necrosis and mitotic activity including atypical mitoses. Adrenal cortical neoplasms in pediatric patients are more difficult to diagnose and to separate adenomas from carcinomas. The diagnosis of pediatric adrenal cortical carcinoma requires a higher tumor weight, larger tumor size and more mitoses compared with carcinomas in adults. Pheochromocytomas are chromaffin-derived tumors that develop in the adrenal gland. Paragangliomas are tumors arising from paraganglia that are distributed along the parasympathetic nerves and sympathetic chain. Positive staining for chromogranin and synaptophysin is present in the chief cells, whereas the sustentacular cells are positive for S100 protein. Hereditary conditions associated with pheochromocytomas include multiple endocrine neoplasia 2A and 2B, Von Hippel-Lindau disease and neurofibromatosis I. Hereditary paraganglioma syndromes with mutations of SDHB, SDHC and SDHD are associated with paragangliomas and some pheochromocytomas.

Phaeochromocytomas and functional paragangliomas: clinical management

Phaeochromocytomas (PH) and functional paragangliomas (FPGL) are neoplasms of adrenal (PH) or extra-adrenal (FPGL) chromaffin tissue that synthesize catecholamines. Catecholamines are converted into inactive metabolites, metanephrines, within the tumour and the diagnosis of PH/FPGL is therefore based on the quantification of plasma or urinary metanephrines. The tumour can be located by computed tomography, magnetic resonance imaging and metaiodobenzylguanidine scintigraphy. Patients are treated by tumour resection following alpha-blockade. PH and FPGL may be sporadic or part of several genetic diseases. Patients with PH/FPGL should be followed up indefinitely as the disease may recur, particularly if they have inherited or extra-adrenal tumours. About 10% of tumours are malignant either at initial surgery or during follow-up. Recurrences and malignancy are more frequent in cases with large or extra-adrenal tumours, and in SDHB mutation carriers. Treatments for progressive malignant PH/FPGL include tumour debulking, metabolic radiotherapy, chemotherapy, and possibly tyrosine kinase inhibitors.

The role of PET in the surgical approach to adrenal disease

BACKGROUND

Appropriate surgical approach to diseases of the adrenal requires a diagnosis sufficient to determine the biochemical status of adrenal dysfunction and anatomic evaluation sufficient to differentiate unilateral from bilateral disease, intra-adrenal from extra-adrenal neoplasm, adrenal tumor recurrence or adrenal metastases. High resolution computed tomography (CT) and magnetic resonance have been the primary imaging modalities for the evaluation of anatomy, while scintigraphic studies have played a secondary role in diagnosis. The recent availability of functional imaging provided by positron emission tomography (PET) with radiopharmaceuticals designed to depict substrate precursor uptake, cellular metabolism or receptor binding in neoplasms and CT as a single modality, hybrid PET/CT, to directly correlate function and anatomy has had a significant impact upon the diagnostic and therapeutic approach to many cancers and has been applied to adrenal disease with some early success that we describe in this review.

METHODS

In addition to the authors' experience, a search of Medline and PubMed databases was performed using search terms: 'adrenal scintigraphy', 'positron tomography', 'computed tomography', 'adrenal surgery', 'adrenal mass', '(18)F-fluorodeoxyglucose', 'adrenal carcinoma', 'adrenal medulla' and 'pheochromocytoma'.

CONCLUSIONS

Present PET radiopharmaceuticals and their use in hybrid PET/CT have demonstrated efficacy in the preoperative and follow-up evaluation of neoplasms of the adrenal cortex and medulla that hopefully will continue to improve with the development of newer tracers that continue to exploit unusual characteristics of the adrenals.

Succinate dehydrogenase B gene mutations predict survival in patients with malignant pheochromocytomas or paragangliomas

CONTEXT

Pheochromocytomas and paragangliomas may be malignant either at presentation or during recurrence, but the clinical course of malignant tumors is unpredictable.

OBJECTIVE

The objective was to analyze survival according to clinical characteristics at diagnosis of malignancy and the presence or absence of SDHB mutations.

DESIGN

This was a retrospective cohort study.

SETTING AND PARTICIPANTS

A total of 54 patients with malignant tumors were included. Malignancy was scored according to the presence of metastases or histologically documented lymph node invasion.

MAIN OUTCOME MEASURES

The main outcome was the specific survival after the diagnosis of the first metastasis.

RESULTS

Germline mutations were identified in SDHB (n = 23, including 21 patients with apparent sporadic tumors) and VHL (n = 1) genes, and two patients had neurofibromatosis 1. Patients were followed up from the diagnosis of primary tumor and from the diagnosis of the first metastasis to the present or to death with medians of 79 [interquartile range (IQR) 24; 190] and 39 [IQR 14; 94] months, respectively. The 5-yr probability of survival after the diagnosis of the first metastasis was 0.55 (95% confidence interval 0.39-0.69). Patients with SDHB mutations were younger, more frequently had extra-adrenal tumors, and had a shorter metanephrine excretion doubling time. The presence of SDHB mutations was significantly and independently associated with mortality (relative risk 2.7; 95% confidence interval 1.2, 6.4; P = 0.021).

CONCLUSION

SDHB mutations, frequent in patients with malignant pheochromocytomas or paragangliomas, are associated with shorter survival. Therefore, SDHB genetic testing may be of prognostic value for such patients, even those with an apparent sporadic and/or benign presentation at diagnosis.

Metastatic malignant phaeochromocytoma: A rare entity that underlies a therapeutic quandary

Phaeochromocytoma is a rare condition that provides a diagnostic challenge as a result of its variable presentation. Treatment of metastatic malignant phaeochromocytoma is also not well defined owing to its rarity. We present four such cases and a review of the literature. The database of the Singapore Cancer Registry was used to trace all cases of metastatic malignant phaeochromocytoma from 1984 to 2004, and the case records were then reviewed retrospectively. There were four patients with metastatic malignant phaeochromocytoma seen in Singapore in the last 20 years. Their variable clinical courses were reviewed and compared with current knowledge and overseas experience in the literature. We further discuss the difficulties in diagnosis, and the dilemma in appropriate management of such cases. Phaeochromocytoma remains a commonly missed diagnosis unless a high index of suspicion is maintained. Malignant phaeochromocytoma has a variable clinical course. There is a place for radical surgery if this can render the patient free of gross disease, or when it can achieve symptom control for palliation and improvement in quality of life. In the metastatic context, debulking surgery does not appear to be of curative benefit, although it may be undertaken for good palliation.

Initial work-up and long-term follow-up in patients with phaeochromocytomas and paragangliomas

Catecholamine-producing tumours may arise in the adrenal medulla (phaeochromocytomas) or in extra-adrenal chromaffin cells (paragangliomas). The most specific and sensitive diagnostic test is the determination of plasma or urinary metanephrine levels. The tumour can be located by computed tomography, magnetic resonance imaging and metaiodo-benzylguanidine scintigraphy. Patients are treated by tumour resection. Phaeochromocytomas and paragangliomas may be sporadic or the result of several genetic diseases: multiple endocrine neoplasia type 2, neurofibromatosis 1, von Hippel-Lindau disease, succinate dehydrogenase-phaeochromocytoma-paraganglioma syndrome. Familial cases are diagnosed earlier and are more frequently bilateral and recurrent than sporadic cases. About 10% of tumours are malignant, either at initial surgery or during follow-up. Recurrences and malignancy are more frequent in cases with large or extra-adrenal tumours and in the succinate dehydrogenase subunit B-related phaeochromocytoma-paraganglioma syndrome. Patients should be followed up indefinitely, particularly if they have familial or extra-adrenal tumours.

Stable disease and improved health-related quality of life (HRQoL) following fractionated low dose131I-metaiodobenzylguanidine (MIBG) therapy in metastatic paediatric paraganglioma: observation on false “reverse” discordance during pre-therapy work up and its implication for patient selection for high dose targeted therapy

The incidence of paraganglioma in the paediatric population is exceedingly rare, accounting for < 0.1% of childhood cancers. We report here the response and toxicity profile in a case of malignant paraganglioma which was treated with what is currently perceived as an unconventional and non-standard approach, using three consecutive low doses of 131I-MIBG (a cumulative dose of 11 647.6 MBq). The patient had a stable disease at the end of 42 months follow-up following the first treatment with 131I-MIBG. Excellent symptomatic and hormonal responses were observed. The only adverse effect was mild nausea in the first 24 h after therapy. In addition to the potentially primary end point of radiological and biochemical response measurement, we, in this paper, endeavoured to look for a quality of life evaluation for this form of treatment. Given the rarity of this condition, the experience gained by this therapeutic approach is intriguing from response and toxicity standpoints and may be extrapolated to malignant pheochromocytoma as well. An apparent "reverse discordance" between 131I-MIBG scintigraphy and 99Tc(m)-MDP bone scan encountered during pre-therapy work up is also described with possible explanations. This draws attention to an important clinical issue in selecting patients for high dose targeted therapy.

Changes in Urinary Total Metanephrine Excretion in Recurrent and Malignant Pheochromocytomas and Secreting Paragangliomas

We quantified urinary excretion of total metanephrines (metanephrine plus normetanephrine) (UETM) in 261 patients with pheochromocytoma (PH) or secreting paraganglioma, before primary tumor resection. We then determined UETM 2 weeks after primary tumor resection and once per year thereafter. The tumor was considered benign in 242 patients and malignant in 19 patients. Patients with malignant tumors had higher UETM and tumor diameters, lower plasma epinephrine concentrations, and were more likely to have secreting paragangliomas than patients with benign tumors. In the 215 patients with a single-benign primary tumor, preoperative UETM and tumor diameter were significantly correlated. Thirty-six patients subsequently developed recurrences or new tumors, which were malignant in 18 cases. All recurrent or new tumors could be detected before the onset of symptoms, on the basis of an increase in metanephrine concentration. We followed one patient with von Hippel-Lindau disease and a new tumor for 50 months before reoperation and found that UETM and tumor diameter were significantly correlated. In patients with malignant tumors, the logarithm of UETM was significantly correlated with time, suggesting an exponential increase in tumor activity and, presumably, tumor burden. Urinary metanephrine excretion is a marker of tumor activity and a surrogate of tumor burden in patients with pheochromocytoma or secreting paraganglioma. UETM excretion could be used to assess treatment response in malignant cases.

[Slight hormonal alterations in a patient with a large pheochromocytoma]

We present a case report that the patient had symptoms suggesting pheochromocytoma, a large tumor (> 50 g) and a single minimally altered laboratorial test, exemplifying a diagnostic pitfall. A 31 y.o. male patient had two acute abdominal events, the last one accompanied by headache, arterial hypertension, facial flushing, perspiration and cutaneous pallor. In another admission, the patient had sustained arterial hypertension and cardiac arrhythmia. From laboratory analysis, the vanililmandelic acid was slightly modified. Scintigraphy disclosed a large adrenal mass suggesting pheochromocytoma. Histopathology confirmed this hypothesis. This report points out that patients with symptoms suggesting pheochromocytoma, even when plasma catecholamines and urinary metanephrines levels are normal, may harbor large tumors with a high catecholamines turnover or that had undergone hemorrhagic necrosis.

The diagnosis and medical management of advanced neuroendocrine tumors

Neuroendocrine tumors (NETs) constitute a heterogeneous group of neoplasms that originate from endocrine glands such as the pituitary, the parathyroids, and the (neuroendocrine) adrenal, as well as endocrine islets within glandular tissue (thyroid or pancreatic) and cells dispersed between exocrine cells, such as endocrine cells of the digestive (gastroenteropancreatic) and respiratory tracts. Conventionally, NETs may present with a wide variety of functional or nonfunctional endocrine syndromes and may be familial and have other associated tumors. Assessment of specific or general tumor markers offers high sensitivity in establishing the diagnosis and can also have prognostic significance. Imaging modalities include endoscopic ultrasonography, computed tomography and magnetic resonance imaging, and particularly, scintigraphy with somatostatin analogs and metaiodobenzylguanidine. Successful treatment of disseminated NETs requires a multimodal approach; radical tumor surgery may be curative but is rarely possible. Well-differentiated and slow-growing gastroenteropancreatic tumors should be treated with somatostatin analogs or alpha-interferon, with chemotherapy being reserved for poorly differentiated and progressive tumors. Therapy with radionuclides may be used for tumors exhibiting uptake to a diagnostic scan, either after surgery to eradicate microscopic residual disease or later if conventional treatment or biotherapy fails. Maintenance of the quality of life should be a priority, particularly because patients with disseminated disease may experience prolonged survival.

Angiogenesis and vascular architecture in pheochromocytomas: distinctive traits in malignant tumors

Angiogenesis is a critical step in tumor growth and metastatic invasion. We here report the study of the vascular status of 10 benign and 9 malignant pheochromocytomas. We examined the vascular architecture after immunostaining endothelial cells (CD34) and vascular smooth muscle cells (alpha-actin) and identified a vascular pattern characteristic of malignant lesions. To define a gene expression profile indicative of the invasive phenotype, we studied by in situ hybridization the expression of genes encoding several pro- and anti-angiogenic factors [hypoxia-inducible factor (HIF-1 alpha), EPAS1, vascular endothelial growth factor (VEGF), VEGF receptors, angiopoietins and their receptor Tie2, five genes of the endothelin system, and thrombospondin 1]. A semiquantitative evaluation of the labeling revealed an induction of genes encoding EPAS1, VEGF, VEGFR-1, VEGFR-2, endothelin receptor, type B (ETB) and endothelin receptor, type A (ETA) in malignant pheochromocytomas as compared to benign tumors. These differences were observed in tumor cells, in endothelial cells, or in both. Quantification by real-time reverse-transcriptase polymerase chain reaction showed an increase of EPAS1, VEGF, and ETB transcripts of 4.5-, 3.5-, and 10-fold, respectively, in malignant versus benign tumors. Furthermore, we observed a strong correlation between the expression of EPAS1 and VEGF in tumoral tissue and between EPAS1 and ETB in endothelial cells. Altogether, our observations show that analysis of angiogenesis provides promising new criteria for the diagnosis of malignant pheochromocytomas.

Pheochromocytoma of the Adrenal gland Scaled Score (PASS) to separate benign from malignant neoplasms: a clinicopathologic and immunophenotypic study of 100 cases

No comprehensive series has evaluated the histologic features of pheochromocytoma to separate benign from malignant pheochromocytoma by histomorphologic parameters only. Fifty histologically malignant and 50 histologically benign pheochromocytomas of the adrenal gland were retrieved from the files of the Armed Forces Institute of Pathology. The patients included 43 females and 57 males, with an age range of 3-81 years (mean 46.7 years). Patients usually experienced hypertension (n = 79 patients). The mean tumor size was 7.2 cm (weight was 222 g). Histologically, the cases of malignant pheochromocytomas of the adrenal gland more frequently demonstrated invasion (vascular [score = 1], capsular [score = 1], periadrenal adipose tissue [score = 2]), large nests or diffuse growth (score = 2), focal or confluent necrosis (score = 2), high cellularity (score = 2), tumor cell spindling (score = 2), cellular monotony (score = 2), increased mitotic figures (>3/10 high power fields; score = 2), atypical mitotic figures (score = 2), profound nuclear pleomorphism (score = 1), and hyperchromasia (score = 1) than the benign tumors. A Pheochromocytoma of the Adrenal gland Scaled Score (PASS) weighted for these specific histologic features can be used to separate tumors with a potential for a biologically aggressive behavior (PASS > or =4) from tumors that behave in a benign fashion (PASS <4). The pathologic features that are incorporated into the PASS correctly identified tumors with a more aggressive biologic behavior. Application of these criteria to a large cohort of cases will help to elucidate the accuracy of this grading system in clinical practice.

A case of metastatic extra-adrenal pheochromocytoma 12 years after surgery

At the age of 53, a 65-year-old man had been diagnosed with extra-adrenal pheochromocytoma in the retroperitoneum and underwent total tumorectomy. Afterward, he had his serum catecholamine periodically measured in an outpatient clinic. In February 1999, 12 years after surgery, he complained of lower left abdominal pain. Computed tomography and magnetic resonance imaging revealed an osteolytic lesion in thoracic vertebrae 11Th (Th 11). Although his basal serum and urine catecholamines were at normal levels, glucagon injection increased blood pressure and plasma catecholamine levels. 131I-metaiodobenzylguanidine (MIBG) scintigraphy was specifically taken up to Th 11. By bone biopsy, the osteolytic lesion in Th 11 was finally diagnosed with metastasis of pheochromocytoma. For post-operative pheochromocytoma, long-term follow-up involving biochemical tests, including serum catecholamines, and MIBG is needed.

[Recent progress in the diagnosis, prognostic evaluation and treatment of pheochromocytomas]

INTRODUCTION

Pheochromocytoma is a catecholamine-secreting neoplasm of chromaffin tissue. It is a rare disease. Biochemical tests should be performed only in patients at high risk of pheochromocytoma, and an imaging procedure only in those with positive biochemical tests.

CURRENT KNOWLEDGE AND KEY POINTS

The most specific and sensitive diagnostic test for the disease is the determination of plasma or urinary metanephrines. The tumor can be located by computerized tomography, magnetic resonance imaging, and specific scintigraphy. Ten to 20% of pheochromocytomas result from hereditary diseases, including multiple endocrine neoplasia type 2, von Hippel Lindau disease, and neurofibromatosis 1. Familial cases are diagnosed earlier, and are more frequently bilateral and recurring than sporadic cases. About 10% of the cases are malignant either at first operation or during follow-up, malignancy being diagnosed by the presence of lymph node, visceral or bone metastases. The probability of a recurrence is positively correlated with the urinary excretion of metanephrines and tumor size. Recurrences are more frequent in cases with ectopic tumors and in those with a low plasma epinephrine to total catecholamine ratio. Patients, especially those with familial tumors or low epinephrine secretion, should be followed-up indefinitely.

FUTURE PROSPECTS AND PROJECTS

Treatment for malignant recurrences includes surgery, therapeutic embolization, chemotherapy, and the application of therapeutic doses of metaiodobenzylguanidine. Metyrosine, phenoxybenzamine, or somatostatin analogs may help to control blood pressure and to alleviate symptoms in patients with malignant pheochromocytoma; however such a treatment has no antiproliferative effect.

Malignant pheochromocytoma with progressive paraparesis in von Hippel-Lindau disease

Pheochromocytomas are a feature of the von Hippel-Lindau disease spectrum, a multisystem disorder of autosomal dominant inheritance. Pheochromocytomas are, however, observed during life with a lower frequency than other features of this disease, such as retinal angiomas, haemangioblastomas of the CNS, and renal carcinomas. We present the highly unusual case of a patient who required an emergency operation for an intradural extramedullary thoracic tumour which was clinically suggestive initially of neurinoma. We present evidence from NMR, histological and isotope scan investigations of this being a pheochromocytoma metastasis and of an additional right-sided paraganglioma at the same height. A detailed history revealed that this patient had suffered from four other pheochromocytomas and two other paragangliomas, in addition to retinal angiomatosis of von Hippel-Lindau disease. This case is extraordinary due to (i) the unusual site of the metastasis, (ii) the neurological requirement for an emergency operation of pheochromocytoma, (iii) metastasis of pheochromocytoma in von Hippel-Lindau disease (only eight previous cases), and (iv) the number of recurrent pheochromocytomas. It clearly demonstrates the necessity for frequent and life-long follow-up in von Hippel-Lindau disease.

Proliferative index in phaeochromocytomas: does it predict the occurrence of metastases?

Evaluation of the malignant potential of phaeochromocytomas in the absence of metastases presents a formidable challenge to both clinicians and pathologists. Until now, no widely accepted clinical, histological, immunohistochemical or molecular method has become available to discriminate malignant from benign phaeochromocytomas. In other endocrine tumours, estimation of proliferative activity by MIB-1 immunostaining has emerged as a promising approach for the determination of metastatic potential. In this study, the utility of MIB-1 immunostaining as a predictive marker for the occurrence of metastases in phaeochromocytomas was evaluated. In addition, the density of S100-positive sustentacular cells was studied, since their depletion has been identified as a negative predictive marker in smaller series. Furthermore, several clinicopathological parameters were evaluated. One hundred and ten patients operated on for a total of 99 benign and 37 malignant phaeochromocytomas were studied. All malignant tumours had documented metastases. The histopathological diagnosis of primary tumours and metastases was reviewed and graded for angioinvasion, capsular extension, and intra-tumoural necrosis. The proliferative index (percentage of MIB-1-positive cells) and the density of S100-positive cells were assessed. In addition, age at resection, associated familial tumour syndromes, tumour size, and tumour location were recorded. Univariate analysis revealed statistically significant correlations between malignancy and proliferative index (p<0.0005) and depletion of S100-positive sustentacular cells (p<0.0005). Fifty per cent of the malignant, but none of the benign phaeochromocytomas had a proliferative index greater than 2.5%. Higher age at resection (p=0. 03), sporadic occurrence (p<0.0005), extra-adrenal location (p<0. 0005), tumour size (p<0.0005), and necrosis (p=0.03) were also significantly associated with malignancy. Logistic regression showed that proliferative index (p=0.0072), size (p=0.0022), and extra-adrenal location (p=0.0012) of the primary tumour were independently predictive for malignancy. In conclusion, this study indicates that assessing the proliferative activity of phaeochromocytomas by MIB-1 immunohistochemistry can predict the occurrence of metastases. The predictive value of S100 immunostaining, tumour size, and extra-adrenal location of the tumour was also confirmed.

Thoracic involvement with pheochromocytoma: a review

Pulmonary manifestations of pheochromocytoma are infrequent and are not well documented. A MEDLINE search in the English language revealed no cases of endobronchial involvement from a pheochromocytoma. We report a case of endobronchial metastases in a 37-year-old woman known to have a recurrent extra-adrenal pheochromocytoma. She presented with symptoms of wheezing and a nonproductive cough for 8 months and was being treated for asthma. A flexible bronchoscopy with endobronchial biopsy established the diagnosis. The patient underwent a Nd-YAG laser photoresection (LPR) to ablate the tumor, which was followed by placement of a Wallstent (Pfizer Medical Technology Group; Rutherford, NJ). She remains well 18 months later, having required multiple palliative LPRs. To our knowledge, this is the first reported case of endobronchial pheochromocytoma. The pulmonary manifestations of this rare disease and their management are reviewed.

Pheochromocytoma and paraganglioma in children: a report of 24 cases of the French Society of Pediatric Oncology

Pheochromocytoma and paraganglioma of childhood are rare neuroendocrine tumors. Urinary catecholamine measurements, metaiobenzylguanidine (MIBG) scanning, computed tomographic scanning, and magnetic resonance imaging have greatly facilitated diagnosis. Prognosis after surgical resection is excellent. In this retrospective series collected from French oncology centers, the risk of tumor progression was studied in order to assess prognostic factors and the optimal diagnostic and therapeutic management. Medical records of 24 children with paraganglioma were reviewed. This tumor occurred at a median age of 12.5 years and in most cases was revealed by arterial hypertension. The diagnosis was made by the demonstration of urinary excretion of catecholamines and their metabolites. Six patients had bilateral adrenal pheochromocytomas; two patients had extra-adrenal paragangliomas. In eight patients, the paraganglioma occurred as a familial disease. Surgical excision was the only therapeutic procedure. With a follow-up of 5.2 years, 14 of the patients are still in first complete remission and 6 have developed metastases or shown tumor progression. Despite a high long-term survival rate, the risk of malignancy and of multifocal involvement is of concern and is associated with a significant rate of late events. The outcome depends on adequacy of tumor resection and must be serially assessed.

Tumor recurrence and hypertension persistence after successful pheochromocytoma operation

Pheochromocytoma is a catecholamine-secreting tumor and a rare cause of hypertension that is usually curable. However, pheochromocytoma may recur as a benign or malignant tumor, and hypertension may persist after successful surgical intervention. The frequency of and risk indicators for tumor recurrence and hypertension persistence after successful surgical intervention have not been adequately studied. We determined tumoral and blood pressure outcome in 129 patients followed-up from initial pheochromocytoma resection to death or to 1994 (796 patient-years). We assessed several candidate indicators for their predictive value for the risk of tumor recurrence or hypertension persistence. Recurrence was defined as the reappearance of disease after normalization of biochemical tests. Pheochromocytoma caused death or persistent or recurrent disease in 28 patients. Of the 114 with benign tumors at initial operation, pheochromocytoma recurred as a benign or malignant tumor 17 to 194 months after initial operation in 16 cases. Kaplan-Meier estimates of pheochromocytoma-free survival were 92% and 80% at 5 and 10 years, respectively. In the 98 living patients without recurrence, Kaplan-Meier estimates of hypertension-free survival were 74% and 45% at 5 and 10 years. In the Cox model, familial pheochromocytoma and a low ratio of plasma epinephrine to total catecholamines were independently associated with recurrence. Familial hypertension and age were similarly associated with hypertension persistence. After surgery for pheochromocytoma, patients should be followed-up indefinitely, especially those with familial tumors or a low epinephrine secretion. Pheochromocytoma should not unreservedly be considered a surgically remediable cause of hypertension.

Metastatic proclivities and patterns among APUD cell neoplasms

Neoplasms of APUD cell origin are quite variable in their metastatic behavior. Whereas pituitary and parathyroid tumors almost never metastasize, all oat cell lung cancers, malignant melanomas, trabecular carcinomas of the skin and medullary thyroid cancers are capable of dissemination. The metastatic proclivity of individual carcinoids, pancreatic and extrapancreatic islet cell tumors, and paragangliomas is much less predictable. In particular, there are no reliable histological markers of risk for lymphatic or hematogenous dissemination. The behavior of many carcinoids, islet cell carcinomas and paragangliomas is relatively indolent, even when metastatic disease is already present. However, unresectable distant metastases, especially liver involvement, connote a poor prognosis. Mortality is more often related to uncontrolled tumor growth and metastasis than to associated endocrinopathies. Curative or debulking surgical resection should be aggressively pursued as recent data show that worthwhile clinical disease-free survival can be realized in at least some patients.

Diagnostic advances in APUDomas and other endocrine tumors: imaging and localization

The different diagnostic imaging modalities available for determining the location of the various APUDomas are discussed with reference to their advantages and disadvantages. The ability to image these lesions, and to be confident in their role in the underlying pathophysiology, and clinical neuroendocrine syndrome causing symptomatology and illness, has proved to be the key to successful treatment. In many instances it is not the diagnosis that is in question, but it is the extent of disease, the location of the lesion, or whether the anatomical abnormality under study is responsible for the complicating symptoms being considered, that are the crucial questions. The ability to locate APUDomas by a variety of direct and indirect imaging or regionalizing modalities, represent a magnificent advance in the management of these tumors. It should, however, be kept in mind that no one modality or diagnostic method can uniformly be relied upon. It is evident that a multimodal, interactive medical team approach is essential to the successful overall management of patients afflicted with these fascinating tumors.

Heterogeneity of the human myocardial sympathetic innervation: in vivo demonstration by iodine 123-labeled meta-iodobenzylguanidine scintigraphy

The normal pattern of the myocardial sympathetic innervation was studied in 15 subjects using single photon emission computed tomography (SPECT) gamma scintigraphy with iodine 123-labeled meta-iodobenzylguanidine (I123MIBG). Seven young subjects (mean age 29.4 +/- 7.5 years SD) with supraventricular tachycardia and eight older patients (mean age 53.0 +/- 5.1 years SD) with normal coronary arteries at cardiac catheterization and normal thallium-201 scintigrams were studied. MIBG uptake in the hearts of six patients with complete cardiac denervation after orthotopic cardiac transplantation was also studied. MIBG scintigrams were reconstructed into bull's-eye target plots and divided into eight equal sectors. Within each sector, four areas representing the apical, two midventricular, and basal regions were defined. There was a reduction in counts in the older group of subjects with normal coronary anatomy (1218.2 +/- 198.4) as compared with younger subjects with supraventricular tachycardia (1124.4 +/- 317.6), (F = 15.0, df = 1, p < 0.001). The difference was lost after adjustment for age (p = 0.2) by means of analysis of covariance. There was a difference in counts within different sectors of the scan (F = 5.7, df = 7, p < 0.001), with lateral and anterior sectors having higher counts than septal and inferior sectors. There was no difference in the counts within areas of the scan (F = 0.04, df = 3, not significant [NS]) or different areas within the sectors (F = 1.1, df = 21, NS). A small diminution of counts (approximately 10%) in the 10 o'clock region of the bull's-eye target plot was observed in some scans.(ABSTRACT TRUNCATED AT 250 WORDS)

Phaeochromocytoma and paraganglioma

Use of current analytical techniques should lead to the successful diagnosis of most catecholamine-secreting tumours, and the experience and confidence which has evolved with the use of HPLC-ECD for plasma and urinary catecholamine estimation, as well as their greater diagnostic sensitivity and specificity, should soon render the older urinary assays based on catecholamine metabolites obsolete. Until then urinary metanephrine estimation will remain the diagnostic metabolite of choice. The diagnosis of small lesions and early recurrences will, however, continue to pose a great analytical challenge, and may call for the use of suppressive tests such as the pentolinium suppression test, venous catheterization, and MIBG scanning. The flow chart used for phaeochromocytoma diagnosis in our department is illustrated in Figure 12; and provides a strategy for the effective diagnosis of all but the most difficult lesions.

Imaging of catecholamine-secreting tumours: uses of MIBG in diagnosis and treatment

MIBG radiolabelled with 131I or 123I is a radiopharmaceutical which is concentrated in neuroendocrine tumours, particularly phaeochromocytomas and neuroblastomas. This permits non-invasive whole-body scintigraphic screening for benign and malignant, familial and sporadic, intra-adrenal and extra-adrenal phaeochromocytomas and primary and metastatic neuroblastomas, with high sensitivity (85-90%) and specificity (> 95%). MIBG is also concentrated in presynaptic terminals of adrenergic, autonomically innervated organs such as the heart, and may be used as a non-invasive in vivo probe to study this system. Large doses of 131I-MIBG and 125I-MIBG have been used experimentally to selectively deliver therapeutic doses of radiotherapy to malignant phaeochromocytomas and refractory advanced neuroblastomas.

Asymmetry of cardiac [123I] meta-iodobenzyl-guanidine scans in patients with ventricular tachycardia and a "clinically normal" heart

OBJECTIVE

Patients with exercise induced ventricular tachycardia associated with a "clinically normal" heart may have an abnormality of the regional distribution of the cardiac sympathetic nerve supply. In this study the regional distribution of the myocardial nerve supply in patients with ventricular tachycardia (VT) and control subjects was examined by [123] meta-iodobenzylguanidine (MIBG) scanning.

PATIENTS AND DESIGN

Eight patients with exercise induced VT and seven patients with VT unrelated to exercise with "clinically normal" hearts were studied and compared with a control group of six subjects with atrioventricular reentrant tachycardia not related to exercise and eight patients with angiographically normal left ventricular function and normal coronary anatomy who had thallium scans without evidence of ischaemia or fixed perfusion deficits.

METHODS

Single photon emission computed tomography gamma scanning was performed in patients three hours after intravenous injection of MIBG. The left ventricular MIBG uptake data was processed into bull's-eye target plots. The inferior portion of the scan frequently showed artefact due to uptake of MIBG in the liver or spleen and was not used for statistical analysis. Asymmetry of uptake was defined as a ratio of uptake exceeding 1.25 in the upper quadrants (posterior (anterolateral free wall)/anterior (anteroseptal region)) of the MIBG scan.

RESULTS

Patients with VT had a higher proportion of asymmetrical MIBG scans (47%) than subjects in the control groups (0%) and this was particularly obvious in the patients with exercise induced VT (62.5%). This suggests that patients with VT may have relative denervation in the septal portion of the left ventricle leading to an imbalance of the sympathetic supply to the myocardium and locally imbalanced sympathetic or parasympathetic interactions. Considerable evidence from animal experiments suggests that imbalance of the sympathetic supply to the myocardium is important in the genesis of ventricular arrhythmia.

CONCLUSIONS

These results support the hypothesis that selective denervation of the human myocardium may be an important mechanism in the genesis of VT in "clinically normal" hearts.

Malignant pheochromocytoma: a series of 14 cases observed between 1966 and 1990

We report 14 patients (9 males, 5 females) aged 15-59 years, treated for malignant pheochromocytoma. These patients were observed during the 1966-1990 period along with 68 other patients presenting benign pheochromocytomas. From the initial general presentation of the 14 patients, two groups could be individualized. In seven patients, the initial presentation seemed benign. After the excision, the recovery was complete, but patients recurred on average 7.8 yr later (range 1-22 yr). Tumors were intraadrenal in six cases (5 single, 1 bilateral) and extraadrenal in one case. In the seven remaining patients, malignancy was evident from the first examination. The tumors were intraadrenal in 2 cases, extraadrenal in 5 cases. Frequency of extraadrenal locations (6/14) was in this series significantly higher than in benign forms (9/68). Diagnosis of malignancy was based on metastases in 12 cases (lymph nodes in 5, bones in 5, liver in 4, lung in 2, brain in 1) and on peritumoral extension in 2 cases. No biological specificity was detected in urinary excretion of catecholamines or its metabolites. In 6 patients so far studied, an uptake of 131I MIBG was found in the tumor and/or metastases. Four patients received therapeutic doses of 131I MIBG and in three of them, this treatment led to a good result within a follow-up range of 12 to 66 months.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Prognostic profile for patients with pheochromocytoma derived from clinical and pathological factors and DNA ploidy pattern

Eighty-eight patients with pheochromocytoma and paraganglioma treated over a 28 year period (1960-1987) were studied. Based on clinical course, they were divided into three prognostic groups: benign (n = 57); multiple (n = 12); and metastatic (n = 19). Using clinical data, histopathologic findings, and tumor nuclear DNA content a prognostic profile for each group was constructed. The following variables were studied: age, familial pheochromocytoma, associated endocrine or neoplastic disorders, number and location of the lesion at diagnosis, size of the tumor, and the nuclear DNA ploidy pattern. Of these prognostic factors the most significant to predict a future malignant clinical course were large size and local tumor extension at time of surgery. Family history of pheochromocytoma, associated endocrine disorders, and young age at presentation predicted multiplicity. Old age, absence of familial pheochromocytoma or related endocrine disorders and DNA diploid tumors seem to be favorable findings. Using these variables in combination may be helpful for early identification of patients with malignant, multiple, or benign pheochromocytoma and paraganglioma.

Multiple endocrine neoplasia type 2 with malignant pheochromocytoma — Long term follow-up of a case by131I-meta-iodobenzylguanidine scintigraphy—

The case of a 33-year-old Japanese man, who has Multiple Endocrine Neoplasia Type 2 (MEN IIa) (Sipple's syndrome) with malignant pheochromocytoma, is reported. He had survived for twelve years since the initial diagnosis of malignant pheochromocytoma. Within this period, he had undergone 131I-meta-iodobenzylguanidine scintigraphy twice, in 1983 and 1990. This is the first case in Japan of a longterm surviving patient with malignant pheochromocytoma followed up by 131I-MIBG scintigraphy. Although he had no exacerbation of clinical symptoms or urinary catecholamine levels, second scintigraphy clearly showed an increase in the tumor size, new metastasis of the malignant pheochromocytoma and exacerbation of the medullary thyroid carcinoma. Compared with any other roentgenological device and hormonal data, 131I-MIBG scintigraphy was seen to be a good tool for evaluating the localization and the progression of tumors. 131I-MIBG scintigraphy is a useful procedure not only for initial diagnosis but also for judging progression in a case of advanced malignant pheochromocytoma.

Extra-adrenal pheochromocytoma

Extra-adrenal pheochromocytomas may arise in any portion of the paraganglion system, although they most commonly occur below the diaphragm. The most common site of occurrence of extra-adrenal pheochromocytoma is the superior para-aortic region between the diaphragm and lower renal poles. Although the traditional teaching has been that 10% of all pheochromocytomas are at extra-adrenal sites, this may be an underestimation. Extra-adrenal pheochromocytomas probably represent at least 15% of adult and 30% of childhood pheochromocytomas. They may be malignant in up to 40% of the cases, although conflicting data add to the uncertainty of this point. Patients with tumors arising at extra-adrenal sites commonly present with headache, palpitations, sweating and hypertension. The diagnosis is most often confirmed by demonstrating increased catecholamine production, usually by measurement of urinary catecholamines and/or their metabolites. CT scanning is presently the imaging procedure of choice for localization. The roles of MRI and 131I-MIBG scintigraphy in the localization process are still being determined. Thorough preoperative pharmacological preparation, attentive intraoperative monitoring and aggressive surgical therapy all have an important role in achieving the safest and most successful outcome. Complete surgical excision is the treatment of choice for primary extra-adrenal pheochromocytoma as well as recurrent or metastatic disease. When residual tumor cannot be resected, medical therapy for symptomatic relief is preferred, since radiotherapy and chemotherapy have limited effectiveness. Extra-adrenal pheochromocytomas are more likely to recur and to metastasize than their adrenal counterparts, making lifelong followup with annual determinations of catecholamine production essential.

Extra-adrenal phaeochromocytoma presenting as fulminant malignant disease with tumour positive sputum cytology

A case of a 69-year-old man with an extra-adrenal malignant phaeochromocytoma is described. Sputum cytology revealed metastatic cells, which have not been reported previously in malignant phaeochromocytoma. This case is also remarkable for the short duration of disease, rapid progression and extensive spread of metastases, the radiological aspect of metastatic lesions shown by chest X-ray, hypercalcaemia and extremely high levels of circulating catecholamines and urinary metabolites.

Clinical significance of the large adrenal mass

Current clinical teaching indicates that large (greater than 5 cm in diameter) adrenal masses are often malignant. In a retrospective analysis of patients studied between 1977 and 1988 with computed tomography (CT), adrenal scintigraphy, and when available, magnetic resonance imaging (MRI) 45 were found to have adrenal masses greater than 5 cm (range 5-19 cm) in diameter. Thirty were benign (16 phaeochromocytomas, six adrenocortical adenomas, four adrenal cysts, two myelolipomas, an adrenal hematoma and a ganglioneuroma). Of 15 malignant masses, there were seven adrenocortical carcinomas, five adrenal metastases and three adrenal lymphomas. With the exception of the adrenal myelolipomas, cysts, and the ganglioneuroma neither CT nor MRI demonstrated sufficient diagnostic specificity to distinguish benign from malignant lesions. Functional scintigraphy with 131I-6-beta-iodomethyl-19-norcholesterol for suspected adrenocortical lesions and 131I-metaiodobenzylguanidine for suspected phaeochromocytomas frequently provided useful information.