Objective: Thoracic ganglioneuroma is sporadic and rarely reported. Pre-operative misdiagnosis often occurs in clinical practice. To improve diagnostic accuracy and facilitate differential diagnosis, we summarised the CT and MRI findings of thoracic ganglioneuroma. Methods: 22 cases of thoracic ganglioneuroma confirmed by surgery and pathology were retrospectively analysed in terms of CT (16 cases) and MRI data (6 cases). Results: Of 22 lesions, 19 occurred in the posterior mediastinum, 2 in the lateral pleura and 1 in the right chest. The CT value of the plain scans ranged from 20 to 40 HU (mean 29.1 HU) in 16 cases. Punctate calcification was noted in four cases. Patchy fat density shadow was found in one case. Arterial-phase CT found nearly no enhancement (6 cases) or slight enhancement (10 cases) with a CT value of 0-12 HU (mean 5.8 HU). In the delayed phase, enhancement was strengthened progressively, and CT value of 10-20 HU (mean 13.6 HU) was achieved after 120 s. T 1 weighted images showed homogeneous hypointense signals in five cases and hypointense signals mixed with patchy hyperintense signal shadow in one case. T 2 weighted images demonstrated heterogeneous hyperintense signals in all six cases, of which the whorled appearance was noted in one case. Gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA)-enhanced MRI found mildly heterogeneous enhancement in the arterial phase, and progressive mild enhancement in the delayed phase. Conclusion: Thoracic ganglioneuroma shows hypodensity in plain CT. On CT and MRI, non-enhancement or slight enhancement in artery phase and progressive mild enhancement in delay phase are characteristic manifestations of ganglioneuroma in the thorax.

The aim of the study was to describe the imaging findings of Askin tumors on computed tomography (CT) and fluorine 18 fluorodeoxyglucose-positron emission tomography (FDG-PET/CT).Seventeen cases of Askin tumors confirmed by histopathology were retrospectively analyzed in terms of CT (17 cases) and FDG-PET/CT data (6 cases).Fifteen of the tumors were located in the chest wall and the other 2 were in the anterior middle mediastinum. Of the 15 chest wall cases, 13 demonstrated irregular, heterogeneous soft tissue masses with cystic degeneration and necrosis, and 2 demonstrated homogeneous soft tissue masses on unenhanced CT scans. Two mediastinal tumors demonstrated the irregular, heterogeneous soft tissue masses. Calcifications were found in 2 tumors. The tumors demonstrated heterogeneously enhancement in 16 cases and homogeneous enhancement in 1 case on contrast-enhanced scans. FDG-PET/CT images revealed increased metabolic activity in all 6 cases undergone FDG-PET/CT scan, and the lesion SUVmax ranged from 4.0 to 18.6. At initial diagnosis, CT and FDG-PET/CT scans revealed rib destruction in 9 cases, pleural effusion in 9 cases, and lung metastasis in 1 case. At follow-up, 12 cases showed recurrence and/or metastases, 4 cases showed improvement or remained stable, and 1 was lost to follow-up.In summary, CT and FDG-PET/CT images of Askin tumors showed heterogeneous soft tissue masses in the chest wall and the mediastinum, accompanied by rib destruction, pleural effusion, and increased FDG uptake. CT and FDG-PET/CT imaging play important roles in the diagnosis and follow-up of patients with Askin tumors.