Problems in the differential diagnosis of abdominal non-organ tumors

Rationale: The differential diagnosis between lesions requiring surgical intervention and those necessitating medical treatment poses a significant problem for current imaging methods of fat-containing masses in the small intestine mesenterium.Aim: To identify differential diagnostic criteria for various fat-containing neoplasms of abdominal cavity at the preoperative stage.Materials and methods: This retrospective study included data from 29  patients (16  women and 13 men, aged 32 to 81 years, mean age 56 years) with fat-containing masses in the small intestine mesenterium who had undergone preoperative examination at N.N. Blokhin National Medical Research Center of Oncology from 2016 to 2020. Abdominal computed tomography (CT) with intravenous contrast enhancement and assessment of the size, contours, structure and involvement of main vessels was performed in all patients. To interpret single soft tissue nodes within the mass, we used our own list of main CT symptoms (number, size, shape, contours and structure of nodes, degree of their contrast enhancement, and maximal amplification).Results: Fat-containing abdominal masses were morphologically verified as follows: mesenteric panniculitis 13  (45%), well differentiated liposarcoma 10  (35%), lymphoproliferative disorders 4  (14%), lipoma and Castleman disease 1  case each (3%). Twelve (12) of 29  patients (41%) had surgery for various types of tumors, while 17  (59%) patients received appropriate medical treatment after a puncture biopsy-based morphological diagnosis. The CT sensitivity for the detection of fat-containing abdominal neoplasms in our series was 93,1%. The paper describes the radiological signs of the above mentioned mass types with an emphasis on the complexity of their diagnosis.Conclusion: In most cases, CT data can accurately differentiate abdominal liposarcomas from other benign and malignant masses in the small intestine mesenterium.