Endocrine Abstracts

Case report: Von Hippel-Lindau Disease (VHL) is an autosomal-dominant disease with almost complete penetrance, characterized by the development of several types of neoplasia. Non-functioning pancreatic neuroendocrine tumours (pNETs) are part of the syndrome in up to 16% of the patients. A 36 year old female with a known diagnosis of VHL (Mutation exon 3) was under surveillance. She had previous surgeries twice for haemangioblastomas, and an adrenalectomy for phaeochromocytoma with a stormy postoperative course.

Investigations: During her surveillance imaging, the MRI scan showed a mass in the tail of pancreas and a possible lesion within the pancreatic head. These lesions were not consistent with either simple pancreatic cysts or serous cystadenomas and most likely represented neuroendocrine tumours. All the lesions were avid on Gallium DOTA-TATE imaging, confirming somatostatin receptor expression.

Treatment: She did not want to have surgery because of the recent adrenalectomy, a young child to look after and high risk of pancreatic insufficiency. She underwent a trial of primary somatostatin analogue (SSAs) therapy (lanreotide, Somatuline Autogel 90 mg monthly) which was well tolerated. After 6 months of treatment, reimaging demonstrated that all the pNETs were stable with no further progression.

Discussion: An important management consideration in VHL patients is their young age and potential of multifocal disease. The disease has slow progression but the malignant potential of this subgroup of pNETs is poorly characterised. Generally surgical intervention is done when the lesion exceeds 3 cm in the pancreatic body and 2 cm in the head, has doubling time <500 days or there is evidence of the regional disease. These criteria are based on limited retrospective data and have not been validated. Repeated pancreatic surgical intervention in such cases risks progressive parenchymal loss resulting in pancreatic insufficiency. Nearly 80% of non-functioning NETs express somatostatin receptors, making them a suitable target for therapy with somatostatin analogues. SSAs are now established treatment for advanced non-functioning enteropancreatic NETs. These drugs have shown to increase progression free survival. Evidence of the efficacy of SSAs in the context of pNETs in VHL is lacking. We report the use of SSA therapy for multiple pNETS in a patient with VHL and it has shown short-term radiological response. This requires confirmation in other patients and long-term response assessment. It raises the possibility of SSA use as an early strategy to delay the need for surgical intervention in VHL-related pNETs, thereby deferring, the associated risks of pancreatic insufficiency.