Objective: To evaluate the efficacy of endoscopic ultrasonography with color Doppler function for the diagnosis of islet cell tumor.
Methods: Endoscopic ultrasonography was compared with other modalities such as ultrasonography, computed tomography, and angiography in the evaluation of seven patients with islet cell tumor and 28 patients with duct cell cancer.
Results: In cases of islet cell tumor, the tumor detection rates by ultrasonography and endoscopic ultrasonography were 86% and 100%, respectively. Color signals were detected in 14% and 100% of the cases of islet cell tumor by ultrasonography and endoscopic ultrasonography, respectively. The pattern of color signals obtained was rich and abundant, showing pulsatile and/or continuous wave patterns. Angiography and computed tomography showed hypervascularity. However, in cases of duct cell cancer, the tumor detection rates by ultrasonography and endoscopic ultrasonography were 96% and 100%, respectively, whereas color signals were detected in 78% with both ultrasonography and endoscopic ultrasonography. The image of blood flow, which was connected to surrounding vessels, showed a linear pattern and few blood flow signals. In these cases, angiography and computed tomography demonstrated encasement of the artery or portal vein without hypervascularity.
Conclusions: Endoscopic ultrasonography was usefull for the localization and differential diagnosis of islet cell tumor because of its excellent ability to visualize small lesions and tumor vascularity simultaneously.