Endoscopic ultrasonography fine needle aspiration (EUS-FNA) cytology has proven to be useful for the evaluation of pancreatic tumors or gastric submucosal tumors. In the present study, utilizing the cell block procedure, we examined a diagnostic approach of endoscopic ultrasonography fine needle aspiration (EUS-FNA) cytology in two patients with these lesions. In patient 1, EUS-FNA cytology showed round cells in loose small clumps with focal rosettes or a ribbonlike structure. Immunohistostaining by the cell block procedure revealed the positivity for chromogranin A and synaptophysin in the tumor cells. We diagnosed a neuroendocrine tumor. In patient 2, EUS-FNA cytology showed spindle tumor cells with nuclear palisading. Immunohistostaining by the cell block procedure revealed the positivity for DOG-1, c-kit, and CD34 in the tumor cells. We diagnosed a gastrointestinal stromal tumor. Our findings suggest that EUS-FNA cytology with the cell block procedure offers diagnostic efficacy in patients with pancreatic tumors or gastrointestinal submucosal tumors.
