Diagnostic dilemma in gastroduodenal lesions: Heterotopic pancreas mimicking gastrointestinal stromal tumours managed by minimally invasive approach – A case series and review of the literature

Background: Heterotopic pancreas (HP) is a rare congenital anomaly, characterised by ectopic pancreatic tissue lacking anatomical and vascular continuity with the main pancreas. Its clinical and radiological presentation often mimics gastrointestinal stromal tumours (GIST), making pre-operative diagnosis challenging. They are usually asymptomatic but can rarely present with symptoms like GI bleed. Methods: This retrospective study analysed the four cases of HP in the gastroduodenal region, diagnosed over the past 4 years. All patients underwent minimally invasive surgical excision based on pre-operative suspicion of GIST. Clinical presentation, imaging findings, surgical approach and histopathological results were reviewed. Results: The study included four male patients aged 18–62 years. The symptoms ranged from post-prandial abdominal pain and discomfort to asymptomatic incidental findings and haemoptysis. Contrast-enhanced computed tomography (CECT) revealed nodular lesions (1.6–2.7 cm) with exophytic or endophytic growth patterns, raising the suspicion for GIST. Robotic-assisted excision was performed in three cases and laparoscopic excision in one. Histopathological examination confirmed HP in all cases, classified as Heinrich type 1 or 2, with one case showing an additional adenomyoma. Conclusion: HP should be considered in submucosal or intramural GI lesions, especially when mimicking GISTs or showing umbilication on endoscopy. Surgical resection is recommended for the symptomatic cases or diagnostic uncertainty, with minimally invasive approaches preferred. Our series highlights the first robotic excision of duodenal HP in the literature.