Introduction: gastrointestinal stromal tumors (GISTs) are specific, generally KIT (CD117)-positive, mesenchymal tumors of the digestive tract displaying KIT or PDGFRA gene mutations. Clinically, they tend to present as solitary tumors of the intestinal wall; more rarely, multiple tumors may occur in one or more organs. Objective: to review the morphological, immunohistochemical and molecular features of multiple, non-metastatic forms of GIST. Sources: review of the literature on Medline, and authors' own experience. Conclusions: multiples GISTs may occur in three different contexts: as spontaneous lesions (in both adults and children); due to familial GIST syndrome (autosomal dominant inheritance); or in association with specific syndromes (e.g. Carney's triad, Carney-Stratakis syndrome, type I neurofibromatosis). Outside these contexts, the existence of multiple GISTs is deemed to be the result of tumor metastasis, and therefore indicative of advancedstage disease. Clinicians need to be aware of these variants, whose prognosis and treatment differ.

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