Background: Brunner's gland proliferation can mimic malignancy; the preoperative diagnosis of this lesion is challenging, and it is accidentally identified during imaging. Most of these lesions are identified as gastrointestinal stromal tumour or malignant tumour. The diagnosis of these lesions requires a histopathological examination.
Case Presentation: Herein, we present a case of Brunner's gland hyperplasia/hamartoma, which was identified as a gastrointestinal stromal tumour at radiography and as submucosal thickening in endoscopy during the routine workup of anemia. However, histopathological examination revealed it to be a Brunner's gland hyperplasia/hamartoma.
Conclusion: A preoperative diagnosis is challenging, so Brunner's gland hyperplasia/hamartoma should be considered as a differential diagnosis. The patient was found to be doing well on followup.