[Additional primary malignancies in patients with gastrointestinal stromal tumors. Proposal for a new classification].

Additional primary malignancies in patients with gastrointestinal stromal tumor (GIST) is not only common but of growing interest in the scientific literature. This association is of great importance in terms of clinical challenge, diagnosis and therapy as well as for the prognosis impact it implies. In the published series there is a tendency to group these patients to determine the specific and distinguishable characteristics of GIST associated with other malignancies. On the other hand, there is no general consensus or unified classification. This classification would be of great interest, as it would unify criteria, agree groups to compare different series and demonstrate whether the aetiology underlying both tumours and the GIST's own characteristics really vary according to the type in question. We undertook a medical literature review and proposed a new classification for patients with GIST associated with other tumours.