Endocrine Abstracts

Background: Succinate dehydrogenase B (SDHB) associated disease has been characterised by the presence of extra-adrenal paragangliomas with a high rate of metastatic transformation. There is currently no consensus as to the appropriate surveillance regimes for these subjects. We present the surveillance data from a single UK institution with an SDHB surveillance regime which includes annual MR imaging of the abdomen, biennial imaging of the neck, thorax and pelvis and annual urinary/plasma metanephrines.

Results: The SDHB cohort includes 76 subjects. Six subjects were ruled out of the study to leave 70 subjects under surveillance. Thirty-three subjects developed a chromaffin tumour. Nine subjects (27% of those with tumours) had metastatic disease, four subjects (12% of those with tumours) had multiple tumours and six subjects were deceased. Of those subjects with tumours 70% (23/33) had abdominal disease, 15% (5/33) had pelvic paragangliomas, and 9% each (3/33) had head/neck and thoracic paragangliomas. Three subjects had renal cell carcinomas. Seven subjects (10% of all SDHB subjects) have had tumours identified on subsequent surveillance imaging which include four subjects with chromaffin tumours, two subject with a renal cell carcinoma (one also having an additional transitional cell carcinoma of the bladder) and one subject with a papillary thyroid carcinoma. One of the chromaffin tumour identified included a 3 mm bladder paraganglioma which was successfully excised. Four further subjects have small lesions identified and being tracked with diffusion weighted MR imaging, potentially suspicious for chromaffin tumours but yet to be confirmed.

Discussion: We advocate an intensive surveillance regime, predominantly focused on the abdomen, in subject with SDHB mutations given that the majority of disease is centred in the abdomen, 10% of these subjects will be found to have disease on subsequent scanning (both chromaffin and non-chromaffin tumours) and approximately a third of those with tumours will develop metastatic disease.