Operative tumour yield obviates preoperative pancreatic tumour localization in multiple endocrine neoplasia type 1

The efficiency of pancreatic tumour localization was prospectively evaluated in 12 consecutive patients with multiple endocrine neoplasia type 1 (MEN1), who were subjected to extirpation of 56 islet cell neoplasms of 0.2-4 cm in diameter (mean 0.8 cm) during pancreatic resection and enucleation. Computed tomography, angiography of the coeliac trunc and superior mesenteric artery, and percutaneous ultrasound correctly localized 7-12% of the tumours and 21-37% of the 19 lesions measuring at least one centimetre in diameter. Transhepatic portal vein sampling correctly located tumour sites in the proximal or distal portions of the pancreas in four out of six patients, but demonstrated unsatisfactory specificity. Intra-operative ultrasound and bidigital palpation of the pancreas had overall sensitivities of 86 and 45%, respectively, and eight lesions below 0.3 cm in diameter remained undetected with intraoperative ultrasound. It is concluded that diagnosis of endocrine pancreatic neoplasms is biochemical in MEN1 and that broad screening of tumour markers efficiently reveals pancreatic involvement decades before the development of a clinically overt disease. Intra-operative ultrasound is a requisite for pancreatic endocrine surgery in MEN1, and it obviates the need for conventional pancreatic imaging unless a pre-operative search for metastatic disease and anatomical aberrations is considered important.