Endocrine Abstracts

Introduction: Malignant pheochromocytomas and paragangliomas (PPGLs) are rare, and knowledge of the natural history is limited.

Material Methods: Data of 7 (7.6%) (out of 109) patients with malignant PPGLs referred to a Tertiary Centre of Endocrinology from Bucharest, Romania, were retrospectively collected. Follow-up ranged from 2004 to 2022. Demographic data, genetic status, site and size of primary tumor, biochemical activity, metastasis time (synchronous/metachronous), therapeutic approach and outcome were analysed.

Results: Six women and 1 man were included in our analysis. Follow-up duration was 14 ± 7.2 years. Mean age at diagnosis was 50.2 ± 14.3 y.o. One patient had RET pathogenic variant, one had Carney-Stratakis Syndrome. For the rest of the patients, we were unable to perform genetic test. Four patients had right PHEO, 2 had bilateral PHEO and 1 had retroperitoneal PGL as the primary tumor. Mean tumor dimensions were 4.3 ± 2.1 cm. The secreting pattern was noradrenergic in 5 patients and adrenergic in 2 of them. Three patients had metachronous metastatic disease (at 10, 8 and 1 years from the first diagnosis). The rest of four had synchronous metastatic disease. All the patients underwent surgery of the primary tumour. Furthermore, one of them had only MIBG therapy, one had MIBG therapy plus PRRT, one had MIBG plus systemic chemotherapy, one patient had surgery plus chemotherapy and of the rest of three had only surgery. As outcome, two patients with surgery only and the patient with surgery plus chemotherapy were lost to follow-up (probably due to exitus), one patient with surgery only is disease free; the patient with MIBG has biochemical inactive disease, the patient with MIBG+PRRT has biochemical active disease, but without any clinical signs and the patient with MIBG and chemotherapy has active disease.

Conclusion: The clinical course of patients with malignant PPGLs is remarkably variable and sometimes independent to treatment. In some situation, patients access to advanced therapeutic approach is limited by the local infrastructure, therefore, patients outcome is not only related to disease characteristics but also to treatment accessibility. Further studies for the PPGLs behaviour to different therapeutic methods are required.