Computed Tomography Appearance of Inflammatory Myofibroblastic Tumor in the Mediastinum

OBJECTIVE: This study aimed to improve the diagnosis of inflammatory myofibroblastic tumor (IMT) in the mediastinum by analysis of computed tomographic (CT) images. MATERIALS AND METHODS: Clinical data, CT, and pathological findings of 6 patients diagnosed with IMT in the mediastinum were retrospectively analyzed. RESULTS: Of the 6 patients, 5 were women, and mean age at diagnosis was 34 years. All the lesions were solid soft tissue masses and ranged in maximum diameter from 5.0 to 8.5 cm, which were located in the anterior (n = 1), middle (n = 2), and posterior mediastinum (n = 3). The anterior mediastinal tumor had a clear boundary. The tumors in the middle mediastinum had indistinct boundaries: one was invading the right wall of the trachea and the other was invading the esophageal wall. A tumor located in the right posterior mediastinum caused osteolysis of the adjacent ribs. A small amount of calcification was seen in the tumor in the right posterior-inferior mediastinum. After administration of contrast, all tumors showed varying degrees of contrast enhancement (range, 17-47 HU) on chest CT scan. Recurrence occurred in only 1 case. CONCLUSIONS: The common CT appearance of IMT in the mediastinum is as a soft tissue mass with uniform density. All tumors show varying degrees of contrast enhancement. Some lesions have clear boundaries; others do not. Computed tomography examination can help to determine the areas involved by lesions and their relationships with adjacent tissues, which facilitates the prediction of the likely surgical requirements.