Multislice computed tomography performance in differential diagnosis of high‐density thymic cyst and thymoma in lesions less than 3 cm

BACKGROUND: This study was conducted to evaluate the performance of multislice computed tomography (MSCT) to diagnose high‐density thymic cysts and thymomas in lesions measuring < 3 cm. METHODS: The records of 42 patients admitted to Ningbo No. 2 Hospital with an anterior mediastinal mass (diameter < 3 cm) suspected of carcinoma originating from the thymus were retrospectively analyzed. All patients underwent surgery and pathological examination. Twenty‐eight were diagnosed with thymic cysts and 14 with thymoma. The features of thymic cysts and thymomas revealed on MSCT were compared. RESULTS: Mediastinal masses with a triangular or teardrop shape and a straight mediastina–lung border were more likely to be diagnosed as thymic cysts (P < 0.05), while those with a bulging nodule–lung border were more likely thymomas (P < 0.05). Using the CT value as a reference for differential diagnosis, the diagnostic sensitivity, specificity, and area under the receiver operating characteristic curve for CT values of non‐contrast CT images, enhanced CT values, and ΔCT values were 0.65 (0.47–0.84), 0.95(0.86–1.00), and 0.96 (0.89–1.00), respectively. CONCLUSION: MSCT of high‐density thymus gland nodules (maximum diameter ≤ 3 cm) can reveal specific features that could be helpful for differential diagnosis.