ThP5.13 - Lessons learnt from a neuroendocrine tumour presenting as choledocholithiasis

Abstract A 79 year old male presented to A&E with obstructive jaundice. A computerised tomography (CT) scan of his abdomen and pelvis showed intra- and extra-hepatic duct dilation, a small calculus within the lumen of the common bile duct (CBD), and gallbladder distension. His liver function tests were deranged, with an alkaline phosphatase of 280IU/L. Successful stone retrieval was achieved by endoscopic retrograde cholangiopancreatography (ERCP), with an interim CBD stent inserted. Within the same admission, the patient underwent an uncomplicated emergency cholecystectomy. Histological analysis highlighted moderate chronic inflammation and fibromuscular hyperplasia, cholesterolosis, and ruled out dysplasia or malignancy. Four weeks later, the patient re-presented with septic obstructive jaundice. A repeat CT scan identified a dilated CBD of 2.2cm, suggesting an occluded stent. On ERCP for stent removal, ampulla narrowing was identified, hence concurrent brush cytology was performed. Due to clinical suspicion, a CT Positron emission tomography (PET) was requested, which identified metabolically active disseminated malignancy, likely pancreatic in origin, and with nodal, liver, and likely peritoneal metastases. A Ca 19-9 subsequently came back raised at 157 kIU/L. Liver biopsy confirmed a poorly differentiated neuroendocrine carcinoma (NEC) with intermediate features between small and large cell NEC. In such cases with discrepancies between treatment success and lack of biochemical improvement, a low threshold of suspicion for further investigation and oncological consideration is imperative.