Endocrine Abstracts

We present the case of a 51-year-old woman who attends the NET service at the Oxford University Hospitals Trust with multiple known secretory paragangliomas (predominantly 3-methoxythyramine), including a carotid body tumour and, most recently, an intrapericardial paraganglioma. She is SDHC mutation positive. Multiple surgical resections of paragangliomas, at sites other than the cardiac lesion, had previously been undertaken. Due to disease progression and symptomatic burden, surgical resection of the intrapericardial paraganglioma was attempted in 2016. Unfortunately, on direct visualisation the tumour was found to be invading the left and right ventricular myocardium, and was supplied by the right coronary artery, which was coursing through the tumour. As such, the tumour was deemed inoperable and the procedure was abandoned. Due to the significant burden of symptoms, and the potential for catastrophic haemorrhage due to disease progression, peptide receptor radionuclide therapy (PRRT) was considered. All tumour sites were shown to be DOTATATE avid on Ga-PET CT. It was hoped that PRRT would halt disease progression and thus reduce the long-term risk of haemorrhage. After thorough discussion of the potential risks and benefits the patients elected for PRRT. Two cycles of Yttrium-90 DOTATATE were administered in July 2017 and November 2017 respectively. Since completing PRRT the patient has reported an improvement in exercise tolerance, though oxygen requirements, and other objective parameters, remain unchanged. Follow-up imaging demonstrated an interval reduction in the size of the carotid body tumour and stability of the intrapericardial tumour.

Conclusion: The decision to treat with PRRT in this case hinged on the assumption that dramatic tumour shrinkage, with resultant catastrophic haemorrhage, was unlikely. Fortunately this has proved to be the case and the patient appears to have enjoyed some symptomatic benefit from treatment. The future risk of catastrophic haemorrhage due to disease progression is unclear, but interval stability of the intrapericardial tumour on post treatment imaging is encouraging. This case illustrates that PRRT treatment is likely safe in the setting of pericardial disease, may help to slow disease progression and is a viable therapeutic option in similarly challenging cases where an applicable evidence base may is a viable therapeutic option in similarly challenging cases where an applicable evidence base may be lacking.