Small cystic insulinoma: value of arterial stimulation venous sampling

Cystic insulinomas are rare, with only three cases having been reported in the literature. It is not difficult to determine the site of such neoplasms, as cystic insulinomas are usually 4-10 cm in diameter. We report a patient with a histologically confirmed cystic insulinoma. This case is unique because of the small size (1.3 cm) of the tumor. Arterial stimulation venous sampling was useful for localizing and distinguishing this tumor from other pancreatic lesions.