[A study on histogenesis of gastrointestinal stromal tumors].

OBJECTIVE

The purpose of this study was to consider the histogenesis of gastrointestinal stromal tumors (GIST).

METHOD

36 cases of GIST were studied by light microscopy, histochemical and immunohistochemical techniques.

RESULTS

In 15 cases of small intestine spindle cell tumors, various sized eosinophilic globules were observed between the tumor cells and were designated as skeinoid fibers, which stained blue with Masson's trichrome and strongly PAS-positive. The positive rate by immunohistochemical methods for S-100 protein and desmin were 44.44% and 8.33% respectively. The immunoexpression of tumor cells was unrelated to their differentiation.

CONCLUSION

Complex immunophenotypes of GIST suggest primitive mesenchymal origin, and small intestine stromal tumors (SIST) are mostly neurogenic which may have been derived from neurilemmal cells or autonomous nerve tissue of the small intestine.