Introduction: Although the standard treatment for stromal tumours is surgery, in locally advanced forms, it is often necessary to achieve tumour downstaging to improve surgical outcomes. Neoadjuvant treatment in gastrointestinal stromal tumours (GISTs) with tyrosine kinase inhibitors, including imatinib, has been shown to be effective in several studies, but the duration of this treatment is still a subject of debate.
Case report: We report a case of a large GIST of the stomach in a 51-year-old patient with atypical presentation that was initially unresectable. Neoadjuvant treatment with imatinib for 16 months resulted in a good response, allowing secondary surgical excision.
Conclusion: Imatinib in neoadjuvant therapy should be continued as long as there is a good response and tolerance to the medication to obtain tumour downsizing compatible with carcinologic excision.
Keywords: GIST; Imatinib; Neoadjuvant therapy; Surgery.