To study the multi-slice spiral computed tomography (MSCT) manifestations of gastrointestinal tract (GIT) and mesenteric tumor and tumor-like lesions in children and correlation with pathologic findings. 22 patients (17 male, 5 female; age ranged from 3 days to 11 years; with mean of 4.2 years) were screened out by ultrasonography (US) at first, then were performed with abdominal non-enhanced CT (NECT) and contrast-enhanced CT (CECT) scans. All CT images were evaluated independently by two radiologists and a consensus was reached regarding the morphologic features for lesions such as size, solid/cyst, unilocular/multilocular and thin/thick wall characteristics. The 26 lesions were categorized into two groups based on CT characteristics of lesions' nature, group 1 with the prominent cystic lesions, group 2 with prominent solid lesions. Group 1 was further divided into two subgroups: group 1A for the cystic lesions with thin walls, and group 1B for the cystic lesions with thick walls. In group 1A, 7 lesions were unilocular cysts (6 lymphangioma, 1 ileum mesenteric cyst) and 5 were multilocular cysts with internal septation (4 lymphangioma, 1 greater omental cyst). In group 1B, 10 lesions in 7 patients were unilocular without internal septation, which had two kinds of shape-cystic and tubular, their histopathological types were all enteric duplication cyst (10 segments, with two patients with 2 or 3 segments each); In group 2, all lesions had solid mass (2 gastrointestinal stromal tumors and 2 enteric non-Hodgkin's lymphoma). The majority of gastrointestinal tumors and tumor-like lesions are cystic and benign. MSCT manifestations of cystic/solid and thin/thick wall may be great helpful for differentiating different types of GIT and mesenteric lesions. MSCT manifestations have close correlations with their topographic sites and histopathologic findings. (C) 2010 Elsevier Ireland Ltd. All rights reserved.