Endocrine Abstracts

Introduction

Pheochromocytomas (PHEO) and paragangliomas (PGL) are neuroendocrine tumors arising from the chromaffin cells of the adrenal medulla and extra-adrenal autonomic paraganglia, respectively. They are rare and generally benign neuroendocrine tumors. However, malignancy (defined as the evidence of metastases in nonchromaffin sites distant from the primary tumor) occurs in 2 to 26%. Malignant PHEO and PGL are very challenging malignancies associated with poor prognosis.

Objective

Descriptive analysis of the clinical and pathological characteristics of patients with malignant PHEO and PGL followed since 1987 at the Endocrinology Department of a tertiary hospital.

Material and methods

Retrospective cohort study based on the clinical files with clinical, biochemical, imaging, histologic examination, genetic and overall survival characterization.

Results

13 patients, mean age at diagnosis 40.77 ± 16.80 years, 53.8% female. At diagnosis: 10 (76.9%) patients with PHEO(2 of them with bone metastasis), 2 (15.4%) with PGL and 1 (7.7%) patient with PHEO and PGL. Diagnosis made by: hypertension difficult to control in 7 (58.3%) patients, symptoms related to the mass in 3 (25%) and incidentaloma in 2 (16.6%). 5 (50%) patients presented elevated urinary and plasma metanephrines, 3 (30%) elevated plasma metanephrines (with normal urinary metanephrines) and 2 (20%) increased urinary metanephrines (without plasma metanephrines results). On CT only one patient had tumor size < 4 cm, 4 (50%) had heterogeneous enhancement and 2 (25%) had necrosis suggestive areas. All patients underwent surgical treatment. In histologic examination, the mean PASS score was 6.50 ± 2.77 and only 1 (12.5%) patient had a PASS score < 4. Metastasis occurred 8.00 ± 6.15 years after diagnosis: bone (n = 3), pulmonary (n = 2), peritoneal (n = 2), kidney (n = 1), pancreas (n = 1), liver (n = 1) and contralateral adrenal gland (n = 1). A genetic study was carried out in 9 patients (MAX, RET, SDHAF2-B-C-D, TMEM127, VHL, NF1) and only 1 was positive for NF1. 2 (15.4%) patients died from complications of the disease, 1 (7.7%) died from pneumonia and 10 (76.9%) are being followed, only one of them without active disease. Mean survival was 13.46 ± 11.98 years.

Conclusion

PHEO/PGL are neuroendocrine tumors with aggressive potential that is very difficult to predict. In this cohort, regarding malignant PHEO/PGL, 83% had symptoms, 88.9% tumors > 4 cm and 87.5% PASS score ≥ 4, characteristics that seem to be more frequently associated with malignancy. Long-term follow-up is essential, as metastases can occur several years after diagnosis. In our data, metastases occurred up to 18 years after diagnosis.