SFEBES2016 Poster Presentations Adrenal and Steroids (41 abstracts)
Introduction: Germline mutations in succinate dehydrogenase subunit B (SDHB) are one of the commonest findings in familial paraganglioma (PGL) syndromes and account for one quarter of PGLs associated with germline mutations. Although the penetrance is low, the malignancy conversion is high; up to 30%. With the increasing availability of genetic testing and the identification of asymptomatic carriers of the SDHB gene mutation, it is therefore important to establish appropriate surveillance protocols. There is currently no consensus as to the appropriate modality or frequency of imaging for these patients.
Objective: We present the experience of a single centre surveillance programme using non-ionising imaging and have combined this with carefully documented clinical outcomes.
Method: Ninety-two patients were identified with an SDHB gene mutation. 27 index patients (6 children) presented with symptoms and 65 patients (17 children) were identified as asymptomatic carriers. All underwent annual clinical review, urine/plasma metanephrines and MRI of the abdomen, with alternate year MRI of the neck, thorax and pelvis.
Results: Fifty-one tumours occurred in the index patients (19752015). A further 19 SDHB-related tumours were identified on surveillance in 17 asymptomatic patients aged 1683 years (15 PGLs, 3 renal cell carcinomas, 1 GIST). Eleven of these tumours were identified on the first surveillance imaging and eight on subsequent imaging; 29 years after the initial negative scan. In total 14 patients had malignant disease, including eight with disseminated metastases.
Conclusions: As there is no single clinical or biochemical test that identifies SDHB-related disease, imaging needs to play a key role in surveillance. We demonstrate that MRI based imaging could be the mainstay of surveillance thereby minimising radiation exposure with annual surveillance such that tumours are identified at stages before they become biochemically active. SDHB-related tumours have been picked up as early as 2 years after first surveillance scan.
07 Nov 2016 - 09 Nov 2016