Gastrointestinal stromal tumors: A pathomorphologic and immunohistochemical study of 77 cases / 临床与实验病理学杂志

ABSTRACT

Purpose　To investigate the pathomorphological and immunohistochemical features of gastrointestinal stromal tumors (GIST). Methods　Light microscopy was used to study the morphologic characteristics of 77 cases of GIST. The expression of c-kit(CD117), CD34, vimentin, SMA and S-100 protein were detected in all cases with S-P immunohistochemical method. Results　GIST tended to have a higher degree of cellularity and lesser degree of cytoplasmic eosinophilia than observed in classic leiomyomas. The neoplastic cells of GIST were spindle, epithelioid or both in different proportion. Focal to prominent cytoplasmic vacuolization was often seen. The histological spectrum included interlacing fascicles, diffuse sheets, storiform and palisading pattern. The formation of cell clusters was rather special. Stromal and vascular hyalinization was common. GIST primary in the mesentery tended to have a higher potentiality of malignancy. The positivity of CD117 and CD34 were 90%, 92%, respectively. Conclusion　The characteristic histological features exist in GIST. The detection of CD117 and CD34 is helpful to differential diagnosis.