Gastro-intestinal stromal tumours (GISTs): prognostic and therapeutic features

The prognostic factors may be different evaluated. The biological behaviour is only hypothetical, according to the duration of symptomatology, the site and size of the tumour, the presence of hemorrhagic or necrotic areas, the cytological modifications and, above all, the number of mytosis: 5 mytosis x 50 HPF are considered significant for malignancy. In last thirty years we have reported 40 GISTs, mostly gastric. All of them have been operated on with simple enucleation or organ resection. In the benign GISTs (26 pts) we have reported early mortality only in 5 cases; in the borderline forms (6 pts), in 4 rapidly evolving cases, the tumour had > 5 cm in size and the mytosis were > 5 x 50 HPF. Also in the malignant GISTs we have noted a good correlation between survival and clinical and histopathological findings. As well in this experience the biological behaviour of GISTs is difficult in interpretation. Anyway the dimensions, the genetic modifications and the number of mytosis are considered good indicators for malignancy. We have always indicated a surgical treatment, enlarged according to the invasion of adjacent organs.