Clinical features and treatment outcome of inflammatory myofibroblastic tumor of the paranasal sinus

: Objective: To investigate the clinicopathological features and the clinical characteristics of inflammatory myofibroblastic tumor(IMT) of paranasal sinus. Method: Five cases of IMT of paranasal sinus treated from 2011 to 2018 were analyzed retrospectively. Of the 5 patients, CT and MRI were performed before operation. All tumors originated from paranasal sinus, and orbital, pterygopalatine fossa and palate was involved with variable degrees. All patients had been given operation and recovered well. Two cases received additional glucocorticoid therapy(prednisone) postoperatively. Result: After a follow-up of 3-80 months, one case recurred 2 years postoperatively and received surgery again. No recurrence was found after operation in the other four patients. The finial diagnosis depended on pathological findings. Postoperative pathological examination showed that the tumor cells were mainly composed of spindle fibroblasts and chronic inflammatory cells. Immunohistochemical staining showed positive expression of SMA protein. Conclusion: IMT of paranasal sinus is a rare clinical entity without specific clinical manifestations and the extent of the lesion can be assessed by imaging examinations. Pathological examination is required for final diagnosis. Radical resection should be taken for limited lesions. Besides surgery, corticosteroid administration and irradiation therapy is recommended in some circumstances. The overall prognosis is good.