Background

GISTs are CD 117 positive mesenchymal neoplasms, mainly located in tubular GI tract, frequently with a very similar histologic pattern and different malignancy. They typically occur as solitary lesions, whereas their occurence as disseminated tumours is usually associated with spread from a primary site. GISTs have three kinds of histologic pattern, the most common of which is the spindle cell pattern. The diagnosis of GIST is by positive reaction for CD 117 and the results of other immunohistochemical reactions, mainly for smooth muscle markers, nervous tissue markers also for endothelial cells marker (CD 34).

Aim

The aim of this study was to present a case of primary multifocal GIST of stomach.

Case description

Two gastric tumours were surgically excised and, after formalin fixation and routine preparation, were tested with antibodies raised against CD 117, desmin, SMA, NSE, S-100 protein, PGP 9.5 and CD 34. The histologic patterns and immunohistochemical results of the two tumours were clearly different.

Conclusions

Conclusions despite evident differences in size and location of these tumours in the stomach wall, both lesions can be looked upon as bifocal primary GIST.