Background <p>Lipoblastoma is a rare benign tumor of embryonic adipose tissue, predominantly affecting infants and young children. Mesenteric lipoblastomas are exceptionally uncommon and pose diagnostic and therapeutic challenges due to their deep intra-abdominal location and potential for extensive growth.</p> Case presentation <p>We report a case of a massive mesenteric lipoblastoma in a 17-month-old patient, presented with extensive abdominal involvement. The child visited surgical clinic with a compliant of progressive abdominal distension over 5 months. Imaging with ultrasound and contrast enhanced abdominal computed tomography revealed a large, well-circumscribed, multi-lobulated fatty mass occupying a significant portion of the abdominal and pelvic cavity. Upon exploration, the mass was found to originate from the mesentery of the transverse colon, surgical excision was performed, and histopathological analysis confirmed the diagnosis of lipoblastoma with features of extensive maturation.</p> Discussion <p>Mesenteric lipoblastomas can mimic other soft tissue tumors and abdominal masses, necessitating thorough clinical, radiologic and histologic evaluation. Complete surgical resection remains the treatment of choice, with an excellent prognosis and low recurrence rates when margins are clear. This case underscores the importance of considering lipoblastoma in the differential diagnosis of pediatric abdominal masses and highlights the potential for significant intra-abdominal expansion without malignant transformation.</p> Conclusion <p>Early imaging and histopathological confirmation are crucial for accurate diagnosis and effective management. Complete surgical excision remains the treatment of choice, with an excellent prognosis and low recurrence rates when resection is complete.</p>