Morphological and immunohistochemical features of gastric glomus tumor:a report of 4 cases

Objective To investigate the morphological and immunohistochemical features of gastric glomus tumor and its differential diagnosis.Methods The sections of the tumors were microscopically observed and immunohistochemical staining was performed for the tumor tissue blocks.Results The prominent morphologic features of gastric glomus tumor included:(1) the tumors were multinodular and usually separated by smooth muscle bundles;(2) the tumor cells were uniform,round or polygonel,had clear or eosinophilic cytoplasm and no cellular atypia and mitotic figures;(3)the tumor cells arranged around blood vessles or sinus showing a hemangiopericytomalike pattern,some tumor cells in solid pattern;focally myxoid change in the stroma were seen.All four cases were positive for SMA,laminin and vimentin,one case was also focally positive for CD34;while other markers including CD117,S100,desmin,CgA,Syn and CK,were all negative.Conclusions Gastric glomus tumor is extremelly rare benign tumor,with distinct morphological and immunohistochemical features and needs to be differentiated from other tumors such as neuroendocrine tumors and epithelioid stromal tumors in the gastrointestinal tract.