Study on the origin and differentiation of gastrointestinal stromal tumors / 中华病理学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To explore the origin and differentiation of gastrointestinal stromal tumors (GISTs).</p><p><b>METHODS</b>Immunohistochemistry staining and electron microscopy were adopted.</p><p><b>RESULTS</b>In 212 cases of primary GISTs, the positive rates of CD117, CD34, alpha-SMA, MSA, desmin, S-100, PGP9.5 were 96.7%, 77.3%, 19.3%, 15.6%, 1.9%, 16.3%, and 12.3% respectively. Among them, GISTs showed a diffuse and strong positivity for CD117. Electron microscopy of tumor cells demonstrated numerous mitochondria, prominent perinuclear Golgi complex, smooth and rough endoplasmical reticulum and intermediate filaments. Irregular caveolae, dense plaque, incontinuous basal lamina were observed occasionally. Cytoplasmic processes were often observed accompanying with local adhesion present between the processes or between the processes and the cell membrane.</p><p><b>CONCLUSIONS</b>Data from both immunophenotype and electron microscopy suggest that GIST might originate from the mesenchymal cells, differentiating to be ICC afterwards, and possessing myoid characteristics in various extent.</p>