[Pancreatic echo-endoscopy and preoperative localization of insulinomas]

Preoperative localization of insulinomas often fails because of the small size of these tumors. The aim of this study was to analyse the value of endoscopic ultrasonography of the pancreas in comparison with them to those of conventional localization procedures.

From 1983 to 1997, 32 patients, operated with a preoperative diagnosis of insulinoma, underwent one or more localization procedures: ultrasonography (US) (n = 31), computed tomography (CT) (n = 31), magnetic resonance imaging (MRI) (n = 10), angiography (ANG) (n = 6), transhepatic portal venous samplings (THPVS) (n = 3), and/or endoscopic ultrasonography (EUS) (n = 25). More recently, 4 patients had scintigraphy with labelled octreotide. During surgery, intraoperative palpation and ultrasonography of the pancreas, performed in all but one cases (laparoscopy), allowed the localization of 29 solitary tumors and 2 multiple tumors (one of which in a case of a MEN II). A malignant tumor was found in 6 patients.

The sensitivity of the localization procedures was as follows: US = 19%, CT = 39%, IRM = 30%, ANG = 33%, THPVS = 0%, EUS = 96%. Labelled octreotide scintigraphy was positive in 3/4 cases. Surgical procedures included: 15 enucleations or partial resections, 14 left pancreatectomies (5 of which with splenectomy), 3 duodenopancreatectomies. In one case the tumor was resected laparoscopically (distal pancreatectomy).

EUS was the best preoperative localization procedure in this study. It may avoid the need for other imaging procedures. Combined with intraoperative ultrasonography, EUS could allow laparoscopic resections in selected cases.