Endocrine Abstracts

Introduction: Advances in the understanding of the natural history and genetics of phaechromocytomas and paragangliomas have altered the demographics of these conditions resulting in much higher rates of malignancy and association with known genetic abnormalities.

Objective: To analyse the clinical and biochemical features of hereditary (H) and sporadic (S) phaeochromocytomas and paragangliomas.

Design: Retrospective case-series at Guys and St Thomas’ NHS Foundation Trust identified using our in-house electronic database (Diabeta-3).

Results: Forty-seven patients were reviewed over a period of 30 years, 36% (n-17) of these patients had hereditary phaeochromocytomas or paragangliomas (SDHB 5, SDHD 2, VHL 5, RET 3, NF1 2).

The hereditary group presented at a significantly younger mean age (S: 44.7±15.3 years, H: 29.5±16.9 years, P=0.006). The hereditary group had significantly more bilateral adrenal phaeochromocytomas (S: 4.5%, H: 45.5%, P=0.03) and a positive trend for multiple paragangliomas, although not statistically significant.

Sporadic tumours were bigger than hereditary but this was not significant (S: 6.39±1.07 cm, H: 3.43±0.85 cm, P=0.25). All patients showed the classic triad of headaches, palpitations and diaphoresis as the most commonly reported symptoms, but hypertension was more prevalent in the sporadic group (S: 60%, H: 35.3%).

Urine catecholamine concentration was highly variable and failed to show any significant difference between both groups. Adrenal phaeochromocytomas secreted more noradrenaline than paragangliomas regardless of their classification. There was no significant difference between the malignant potential of tumours however only adrenal phaeochromocytomas showed malignant change.

Conclusions: The data suggest that patients with hereditary phaeochromocytomas and paragangliomas present at a younger age with more bilateral tumours compared to the sporadic group. There may be a higher susceptibility fro malignancy in adrenal tumours compared to extra-adrenal tumours. It is difficult to differentiate the 2 groups based on clinical presentation, size and features of catecholamine secretion. Genetic testing remains key to differentiating between sporadic and hereditary disease.