Accurate diagnosis of early PAMT is difficult, but there are certain morphological and immunophenotypic features enabling differentiation of this<unk>  from GIST or other mesenchymal gastric<unk> s. The diagnosis of submucosal<unk> s is performed by endoscopic ultrasonography (EUS), whereas the<unk>  phenotype and the<unk>  cell type can be evaluated by EUS-guided fine needle aspiration and immunohistochemical analysis. Immunohistochemically, the<unk> r cells show positive staining for vimentin and smooth muscle actin (SMA). Focal desmin positivity may be present. The<unk> r cells are generally negative for CD117, DOG1, SMA, Caldesmon, CD34, Epithelial membrane antigen (EMA), Cytokeratin or Anaplastic lymphoma kinase (ALK). Focal CD10 positivity can be observed. The pattern of positivity indicates the myofibroblastic nature of the<unk> r cells.
Plexiform angiomyxoid myofibroblastic tumor
Inflammatory myofibroblastic tumour
Perivascular epithelioid cell tumour
Sclerosing epithelioid fibrosarcoma
Multinucleate cell angiohistiocytoma
Desmoplastic small-round-cell tumor
Malignant ectomesenchymoma
Angiomatoid fibrous histiocytoma