Abstract
INTRODUCTION: Mesothelial gastric cysts are exceedingly rare in pediatric patients, often mimicking mesenteric or duplication cysts. This case highlights diagnostic challenges and underscores the importance of histopathological confirmation. PRESENTATION OF CASE: A 3-year-old boy presented with 6 months of progressive abdominal distention and intermittent pain. Imaging revealed a 12 × 10 cm unilocular cystic mass, initially suspected to be mesenteric. Intraoperatively, the cyst originated from the gastric wall. Complete excision and histopathology confirmed a mesothelial cyst. Histopathology showed a unilocular cyst lined by flattened mesothelial cells resting on a fibro-collagenous wall, without atypia or mitoses. DISCUSSION: Gastric mesothelial cysts are rarely reported in children. Surgical excision remains definitive, with no recurrence at 6-month follow-up. CONCLUSION: This case emphasizes the need to consider rare gastric cysts in pediatric abdominal masses and the role of histopathology in diagnosis.