Objective To clarify the clinical,morphological and radiological features of extraaxial schwannomas in various locations.Methods A total of 87 patients with schwannoma were analyzed in this report.Locations of tumors included salivary gland(n=13),tongue(n=2),neck soft tissue(n=32),trunk wall(n=4),mediastinum(n=10),liver(n=1),stomach(n=1),retroperitoneum(n=8),and extremities(n=16).Fifty-nine contrasted CT examinations,and 38 MRI examinations were available before surgery.ResultsSixty-nine percent of tumors(60 out of 87)were either fusiform or ovoid shaped.Well-delineated margins were observed in all 87(100%)tumors.In this report,patterns of enhancement were diversified.The 38 MRI examinations revealed that 4(11%)cases showed target sign;8(21%)cases presented fascicular sign;and 20(53%)cases showed split fat sign.No contrast enhanced cystic or necrotic areas were observed in 52 of 87 cases(60%).Conclusion Most schwannomas showed non-specific imaging appearances.However,recognition of the fusiform or ovoid shape,well-delineated margin of the tumor,the three signs on MRI images(the target sign,the fascicular sign and the split fat sign),and the cystic or necrotic areas in tumors could be helpful for diagnosis.
展开▼
