[Diagnostic and therapeutic strategy of insulinomas. Apropos of a personal experience of 21 cases].

Insulinomas account for about 90% of all pancreatic endocrine tumors and their surgical resection leads to cure in 90% of patients. Although current laboratory tests have simplified the clinical diagnosis of insulinomas, despite recourse to an array of most preoperative diagnostic procedures in 10-15% of patients the exact location of the tumor remains undefined. Tumor localization is difficult because: 80% of insulinomas measure less than 2 cm, about 10-12% of insulinomas are multicentric and 4-6% escape detection because are multiple endocrine neoplasms (MEN). If preoperative imaging fails to detect the site of the lesion, the surgeon could be obliged to perform a "blinded resection" with high risks of failure. The Authors refer their experience in a series of 21 patients operated on for insulinoma over the past 8 years (1987-1995). Arteriography with calcium stimulation (ASVS) and scintigraphy with 111-Indium-labeled octreotide performed in the later 16 and 13 cases respectively, achieved a correct tumor localization (confirmed by surgery) in 100% and 84.7% of patients. Intraoperative ultrasonography, performed in 18 cases, allowed not only to localize the tumor but also to study the tumor's neighbouring anatomic structures (Wirsung duct. splenic artery and vein), thus providing the anatomical and surgical information necessary to plan the right surgical strategy (tumor enucleation or pancreatic resection). Tumor enucleation was performed in 15 patients, distal pancreatic resections in 5 cases and multiple liver biopsies in 1 case: this patient had liver micrometastases from a malignant insulinoma without a palpable tumor. Operative mortality was nil. Postoperative complications occurred only in 5 of the 15 enucleations (1 pseudocyst successfully treated with a ultrasound-guided drainage and 4 pancreatic fistula resolved by medical therapy).