High rates of the SDHB p.Arg46Gln pathogenic variant predisposes New Zealand Māori to phaeochromocytoma/paraganglioma.

BACKGROUND

Phaeochromocytomas (PCC) and paragangliomas (PGL; together PPGL) are rare tumours of the adrenal medulla or extra-adrenal paraganglia. They may secrete catecholamines with significant cardiovascular effects. Management of PPGL is predominantly surgical, despite the anaesthetic risks related to potential haemodynamic instability. Meticulous pre-treatment and intra-operative management are required to improve cardiovascular outcomes.

AIMS

There are limited local data regarding the incidence of PPGL and the clinical characteristics of individuals diagnosed with these tumours in New Zealand. We undertook a retrospective study investigating the local practice and patient characteristics with an additional focus on intra-operative haemodynamic stability and post-operative outcomes.

METHODS

Electronic patient records were searched for individuals with a diagnosis of PPGL. Clinical records and electronic databases were interrogated for pre-operative, intra-operative and post-operative data points. Particular attention was paid to rates and types of germline mutations, intra-operative haemodynamic stability and post-operative renal and cardiovascular outcomes.

RESULTS

We identified 49 individuals with PPGL, of whom 34 were from the local area. This gave a local incidence of PPGL of around five cases per million people per year. Māori were significantly over-represented in our cohort, with this being in part due to high rates of the SDHB R46Q mutation. Over 95% of our cohort met pre-specified pre-operative blood pressure parameters. Intra-operative monitoring revealed a tendency to hypotension, but this did not translate into adverse post-operative outcomes, which were infrequent.

CONCLUSIONS

Māori were over-represented due to high rates of germline SDHB R46Q mutations. There were few post-operative adverse outcomes in this contemporary cohort.