Predicting Role of Preoperative Computed Tomography Features on Invasiveness of Thymic Neoplasms

Objective: The anterior mediastinal masses are composed of neoplasms from many different groups, thymic epithelial tumors being the most common type. Histologic subtype, tumor stage and completeness of resection are considered to be the most important prognostic factors in thymic malignancies. The aim of this study is to evaluate the association between the preoperative Computed Tomography characteristics and the histological types, mostly focusing on thymic neoplasms. Materials and Methods: Preoperative Computed Tomography features and pathologic data of 40 patients who underwent surgery due to an anterior mediastinal mass were retrospectively analyzed. Patients are grouped as thymomas, thymic carcinomas and others. Results: Computed Tomography characteristics such as shape, contour, necrosis, lymph node enlargement, surrounding organization, pathologic invasion pattern, internal density, presence of cystic component, pleural/pericardial effusion and calcification were compared with histologic subtypes. Among these parameters solely pathologic invasion and surrounding organization were statistically different between the groups (p0,05). Conclusion: According to the results of our study, Computed Tomography imaging has a limited role in predicting stage and malignant potential particularly for thymic neoplasms and anterior mediastinal masses.

___

[1] Strollo DC, Rosado de Christenson ML, Jett JR. Primary mediastinal tumors. Part 1: tumors of the anterior mediastinum. Chest 1997; 112(2):511-22.

[2] Engels EA. Epidemiology of thymoma and associated malignancies. J Thorac Oncol 2010; 5(4):260-5.

[3] Kim ES, Putnam JB, Komaki R et al. Phase II study of a multidisciplinary approach with induction chemotherapy, followed by surgical resection, radiation therapy, and consolidation chemotherapy for unresectable malignant thymomas: final report. Lung Cancer 2004; 44(3):369-79.

[4] Lucchi M, Ambrogi MC, Duranti L et al. Advanced stage thymomas and thymic carcinomas: results of multimodality treatments. Ann Thorac Surg 2005; 79(6):1840-4.

[5] Zhao Y, Chen H, Shi J et al.. The correlation of morphological features of chest computed tomographic scans with clinical characteristics of thymoma. European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery 2015; 48(5):698-704.

[6] Tomiyama N, Johkoh T, Mihara N et al. Using the World Health Organization Classification of thymic epithelial neoplasms to describe CT findings. AJR Am J Roentgenol 2002; 179(4):881-6.

[7] Shahrzad M, Le TS, Silva M et al.. Anterior mediastinal masses. AJR Am J Roentgenol 2014; 203(2):128-38.

[8] Shen Y, Gu Z, Ye J et al.. CT staging and preoperative assessment of resectability for thymic epithelial tumors. J Thorac Dis 2016; 8(4):646-55.

[9] Marom EM, Milito MA, Moran CA et al. Computed tomography findings predicting invasiveness of thymoma. J Thorac Oncol 2011; 6(7):1274-81.

[10] Priola AM, Priola SM, Di Franco M et al. Computed tomography and thymoma: distinctive findings in invasive and noninvasive thymoma and predictive features of recurrence. Radiol Med 2010; 115(1):1-21.

[11] Qu YJ, Liu GB, Shi HS et al. Preoperative CT findings of thymoma are correlated with postoperative Masaoka clinical stage. Acad Radiol 2013; 20(1):66-72.

[12] Tomiyama N, Muller NL, Ellis SJ et al. Invasive and noninvasive thymoma: distinctive CT features. J Comput Assist Tomogr 2001; 25(3):388-93.

[13] Jeong YJ, Lee KS, Kim J et al. Does CT of thymic epithelial tumors enable us to differentiate histologic subtypes and predict prognosis? AJR Am J Roentgenol 2004; 183(2):283-9.

[14] Sadohara J, Fujimoto K, Muller NL et al. Thymic epithelial tumors: comparison of CT and MR imaging findings of low-risk thymomas, high-risk thymomas, and thymic carcinomas. Eur J Radiol 2006; 60(1):70-9.

[15] Harris K, Elsayegh D, Azab at al. Thymoma calcification: is it clinically meaningful? World J Surg Oncol 2011; 9:95.

[16] Chen JL, Weisbrod GL, Herman SJ. Computed tomography and pathologic correlations of thymic lesions. J Thorac Imaging 1988; 3(1):61-5.

[17] Marom EM. Imaging thymoma. J Thorac Oncol 2010; 5(4):296-303.

[18] Hayes SA, Huang J, Plodkowski AJ et al. Preoperative computed tomography findings predict surgical resectability of thymoma. J Thorac Oncol 2014; 9(7):1023-30.

[19] Hu YC, Wu L, Yan LFet al. Predicting subtypes of thymic epithelial tumors using CT: new perspective based on a comprehensive analysis of 216 patients. Sci Rep 2014; 4:6984.