Abstract
Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm that usually occurs in the lungs or abdominal organs. We report a case of IMT arising in the mediastinum which mimicked a cystic lesion. A 65-year-old woman was found to have an abnormal shadow in the mediastinum on chest computed tomography (CT). Contrast enhanced chest CT showed an oval shaped tumor, 5 cm in diameter, in the mediastinum. Magnetic resonance imaging showed that the tumor was low intensity on T1WI and high intensity on T2WI. The tumor was considered to be a cystic lesion, such as a bronchogenic cyst, esophageal cyst, or a neurogenic tumor with cystic change. A video-assisted tumorectomy was performed. On pathology, spindle-shaped cells which had proliferated in abundant myxoid matrix along with infiltration of inflammatory cells were noted ; a diagnosis of inflammatory myofibroblastic tumor with increased myxoid matrix was made. Although IMT is a rare disease, it should be considered in the differential diagnosis of a mediastinal tumor.
