ENDOSCOPIC ULTRASOUND (EUS) AND EUS GUIDED RADIOFREQUENCY ABLATION (RFA) AS A DIAGNOSTIC AND THERAPEUTIC INNOVATION FOR INSULINOMA

A CASE REPORT

Abstract

INTRODUCTION/BACKGROUND
Though rare in occurrence, insulinomas are the most common hormone-producing pancreatic neuroendocrine tumour (PNET) with a reported incidence of 4 cases per million per year. Surgical intervention has been the gold standard of treatment for insulinoma but an emerging minimally-invasive method – endoscopic ultrasound (EUS) guided radio-frequency ablation (RFA) is increasing in use in the current management of insulinomas. We present a case where EUS and EUS-guided RFA played a pivotal role in localising the lesion and serving as a therapeutic approach.

CASE
A 55-year-old female with underlying primary hypothyroidism, bronchial asthma, and class III obesity presented with refractory hypoglycaemia. Biochemical workup confirmed hyperinsulinaemic hypoglycaemia (plasma glucose 1.6 mmol/L, plasma insulin 107 pmol/L and serum c-peptide 1106 pmol/L). Initial imaging with computed tomography (CT) scan failed to localise any pancreatic lesion. Subsequent EUS discovered a hypoechoic lesion at the pancreatic tail which was later histologically confirmed to be PNET. The patient was treated with subcutaneous octreotide and oral diaxozide, then underwent EUS-RFA rather than surgery due to high operative and anaesthetic risk. The procedure was uneventful however, she developed acute pancreatitis two weeks later. Following recovery from pancreatitis, she remained in euglycemic state for a few weeks before she developed a recurrence of hypoglycemia, albeit being less frequent and less severe (plasma glucose 1.9 mmol/L, plasma insulin 67.3 pmol/L and C peptide 1179 pmol/L). Repeat diagnostic and therapeutic EUS are planned for her.

CONCLUSION
EUS is a valuable tool as a diagnostic modality in localizing insulinoma. It can be an alternative therapeutic option to surgery, especially among high-risk patients.