Gastrointestinal stromal tumors--value of CD34 antigen in their identification and separation from true leiomyomas and schwannomas

摘要: The term "gastrointestinal stromal tumor" (GIST) has been applied to mesenchymal tumors that represent neither typical leiomyomas nor schwannomas. In this study we analyzed immunohistochemically 67 histologically benign [ 5 mitoses/10 HPF) and compared them with 10 schwannomas of the gastrointestinal tract. GISTs spindle cell pattern (67 cases) were typically negative for muscle markers (only 3% positive desmin 25% alpha-smooth actin) S100 protein, but 70% cases CD34, myeloid progenitor antigen also present in endothelial cells some fibroblasts. However, none was CD31 (PECAM-1), a more cell-specific antigen. absence GIST separates it from Kaposi's sarcoma, tumor known be both CD34 CD31. Fourteen epithelioid type showed an immunophenotypic profile similar tumors. small intestinal commonly actin less than gastric malignant features essentially those corresponding contrast, all protein. Gastrointestinal S100-protein positive, CD34. Our results show can immunophenotypically divided categories correlate light microscopically defined diagnostic entities, namely leiomyomas, schwannomas, GIST, most latter representing primitive are positive.