MON-903 Sporadic Phaeochromocytoma, Pancreatic Neuroendocrine Tumour and a Sacral Hibernoma: A Case Report

Most phaeochromocytomas and pancreatic neuroendocrine tumours are sporadic in nature however the presence of multiple neuroendocrine tumours raises the suspicion of a hereditary endocrinopathy. Hibernomas, benign tumours that morphologically resemble brown fat, do not possess a clear aetiology and a link with other neuroendocrine tumours remains unclear. We report an unusual case of a concurrent sporadic phaeochromocytoma, pancreatic neuroendocrine tumour and a sacral hibernoma. A 61 year old female presented with a 3 month history of abdominal pain which led to the discovery of a lesion in her right adrenal gland and a soft tissue mass at the pancreatic tail on a CT Abdomen. The adrenal lesion was biochemically suggestive of a phaeochromocytoma (plasma normetanephrine 4930 pmol/L, plasma 3-methoxytyramine 580 pmol/L, urinary noradrenaline 5564 pmol/day, urinary dopamine 4720 nmol/day). A 68Ga-DOTATATE-PET-CT scan revealed DOTATATE avid lesions in the right adrenal gland, tail of pancreas and right sacral ala. Following preoperative medical therapy, the patient underwent a right adrenalectomy and a resection of the distal pancreatic lesion.Histopathology confirmed a phaeochromocytoma with no conscipicouous mitotic activity, and the pancreatic tail lesion was consistent with a well-differentiated neuroendocrine tumour (NET) (Ki-67 score <3%). Following normalisation of the serum catecholamines, a biopsy of the sacral lesion was undertaken, which returned positive for a hibernoma. Genetic testing revealed no identifiable genetic mutations.This case reports the synchronous presence of a phaeochromocytoma, pancreatic NET and sacral hibernoma with no identifiable genetic mutation. To date, the association between hibernomas and neuroendocrine tumours has not been fully established, but a few case reports suggest a possible association between MEN1 and hibernomas.