Sporadic pancreatic somatostatinomas: 3 cases

AM Brooke; TT Cheung; K Metcalfe; E Carlsen; D Berney; S Bhattacharya; PN Plowman; JP Monson; WM Drake

Sporadic somatostatinomas are rare neuroendocrine tumours (NETs), classically presenting with hyperglycaemia, cholelithiasis and steatorrhoea. The mainstay of treatment is surgical resection; other aspects of management remain uncertain. We report 3 cases. Case 1: A 55 year-old female presented with abdominal discomfort and steatorrhoea. Computed tomography (CT) demonstrated a 9 cm pancreatic mass. Biopsy suggested a NET. Somatostatin (SMS) was 160 pmol/l (normal 0-150). ¹²³I₂-MIBG tracer was positive. Histology after surgical resection confirmed a NET staining for SMS and chromogranin. No uptake was seen following an adjuvant dose of ¹²³I₂-MIBG. 18 months post surgery she remains disease free on CT and SMS of 68pmol/l. Case 2: A 63 year-old female with type 2 diabetes presented with a 10 year history of abdominal pain and diarrhoea. CT identified an extensive mass infiltrating the kidney with widespread lymph node involvement. Debulking surgery revealed a NET staining for SMS and gastrin. Post-operative SMS >1000 pmol/l. ¹²³I-MIBG and ¹¹¹-Indium labeled octreotide (OT) scanning were negative. 5 years after Cisplatin and Etoposide chemotherapy (6 cycles) SMS was 359 pmol/l, but subsequently rose to >1000 pmol/l. Eight years after presentation she remains well. Case 3: A 76 year-old man with type 2 diabetes presented with diarrhoea, vomiting and weight loss. Ultrasound visualised a pancreatic mass, biopsy suggesting a NET. SMS was 87pmol/l, chromogranin A 359pmol/l (normal 0–60) and chromogranin B 263pmol/l (normal 0–150). 3 years after distal pancreatectomy he developed diarrhoea, weight loss and right upper quadrant pain. CT demonstrated local recurrence, liver metastases and retroperitoneal lymphadenopathy. Liver biopsy confirmed NET staining positively for chromogranin and SMS. SMS was 137 pmol/l, chromogranin A 904 pmol/l and chromogranin B 216 pmol/l. The tumour was non ¹²³I₂-MIBG avid. Creon, Loperamide and OT improved his diarrhoea. He is currently undergoing Capecitabine and CCNU chemotherapy. These cases emphasise the need for a multi-disciplinary approach to the management of somatostatinomas.

Endocrine Abstracts

P11