ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Endocrine Abstracts (2017) 50 P285 | DOI: 10.1530/endoabs.50.P285

Prevalence of paraganglioma at first screen in SDH mutation carriers identified through family screening

Isra Ahmed Mohamed1, Anand Velusamy1, Louise Izatt2, Adrian Li1, Mamta Joshi1, Louise Breen1, Barbara McGowan1, Jake Powrie1, Rupert Obholzer3 & Paul V Carroll1

1Department of Endocrinology, Guy’s and St Thomas’s NHS Foundation Trust, London, UK; 2Clinical Genetics, Guy’s and St Thomas’s NHS Foundation Trust, London, UK; 3ENT, Guys & St. Thomas’ NHS Foundation Trust, London, UK.

Introduction: Mutations in the succinate dehydrogenase gene (SDH) predispose to the development of paraganglioma (PGL) which arise from parasympathetic and extra-adrenal sympathetic-associated chromaffin tissues. Identification of an index case results in family ‘cascade’ screening, often of asymptomatic individuals.

Aims: To identify prevalence of PGL tumours and elevated plasma metanephrines at first screening in patients newly identified as carrying a pathogenic SDH mutation.

Methods: Data collection from a database of patients with SDH mutations at Guy’s and St. Thomas’s NHS Foundation Trust. Following confirmation of a pathogenic SDH mutation all patients had measurement of plasma metanephrines and whole-body (incl. head & neck) MRI.

Results: 35 adult patients (mean age 39 years; range 10–66) were included. All were asymptomatic and identified as carrying a mutation in SDH through family screening (3 with SDHA, 24 with SDHB, 3 with SDHC and 5 with SDHD). Using MDM records initial biochemical and cross-sectional screening results were obtained. 10 of 35 patients (29%, 5 with SDHB mutation and 5 with SDHD mutation) had a tumour at initial screening. Tumour locations were as follows; 4 head and neck (3×SDHD, 1×SDHB), 5 abdominal (2×SDHD, 3×SDHB) and 1 thoracic (SDHB). 4 patients had elevated metanephrines at initial screening (11%), one of whom had a malignant tumour detected 6 months from initial screen in the thorax (SDHB mutation).

Conclusion: The tumour burden is high (29%) in these adult patients with SDH mutations at initial screening. Tumours were located in the head & neck, abdomen and mediastinum. Not all abdominal tumours were associated with demonstrable catecholamine excess.