The Comparative Study of CT and Pathology in Intra-abdominal Desmoid Tumors

Objective:To investigate the CT imaging and pathology features of intra-abdominal desmoids tumors(DT).Methods:CT imaging features of 10 cases with intra-abdominal DT proved by pathology were retrospectively reviewed and compared with pathological results.Results:Among the 10 cases,6 cases were located in the abdominal cavity and 4 cases in the retroperitoneum.The maximum tumor size ranged from 4.3 to 17.1 cm.4 cases were irregular and 6 cases were ellipse.5 tumors had well-defined contours,the other 5 cases showed ill-defined contours.3 cases showed complete or incomplete encapsulation.All the 10 cases underwent CT plain and enhanced scan.On CT plain imaging,the lesions showed homogeneous density in 3 cases,the others showed heterogeneous density,one of which had flaky hemorrhage.There was no necrosis or calcification in all lesions.All the tumors showed lower density than iliopsoas.On CT enhanced scan,10 lesions presented slight heterogeneous enhancement in the arterial phase and continuous enhancement in the venous phase.Under the microscope,the spindle fibroblasts were bunchy distribution with no obvious heteromorphism and rare karyokinesis.The collagen fibers showed proliferation and mucinous degeneration.Positive immunohistochemical staining:Vimentin 100%(10/10).Negative immunohistochemistry staining:CD34 90%(9/10),S-100 90%(9/10),CD117 100%(10/10),SMA 80%(8/10).Conclusion:Intra-abdominal DT has characteristic features on CT imaging and plays an important role in the diagnosis and distinction between DT and other tumors in abdomen.