Primary mediastinal seminoma: imaging features correlated with clinical findings

GU Lingling; ZHANG Lanfang; SHEN Wenrong; HOU Ning; HUANG Shengfu; XIE Xiaodong

doi:10.3969/j.issn.1009-0460.2017.12.013

Abstract：Objective To investigate the appearance of primary mediastinal seminoma on CT and MRd correlated with clinical features.Methods From April 2012 to February 2017 in Jiangsu Cancer Hospital,pathological characteristics and imaging findings of 13 patients with histopathological proven mediastinal seminoma were retrospectively reviewed and analyzed.Results All of the 13 patients were male and the median age was 35 years,among whom 7 patients were tested with elevated β-HCG,13 cases were tested with negative AFP.Thirteen cases of mediastinal seminoma were all located in the anterior mediastinum including 12 cases bearing irregular masses,and 12 masses were greater than 5 cm.Thirteen masses revealed homogeneous attenuation on non-enhanced CT images and showed homogeneous and slight enhancement after contrast administration with small areas of low density,and 4 masses with stippled calcification.Tumors encircling macrovasular were found in 12 cases,and hilar lymphadenophathy were identified in 2 cases.The masses appeared slightly hypointense on MRI T1WI and slightly hyperintense on T2WI(SPAIR).Among the 13 patients,3 cases were with complete resections,while 11 cases underwent biopsies,and 5 cases of them were misdiagnosed.One patient was diagnosed by surgery and four patients were diagnosed depending on pathological section again or repeated biopsy,and immunohistochemical analysis.Conclusion The gender,age of onset,the serum levels of tumor markers and imaging findings of primary mediastinal seminoma have certain characteristics.CT-guided percutaneous biopsy is the cause of misdiagnosis sometimes,so final diagnosis depends on clinical feature,serum levels of tumor markers,image findngs and further immunohistochemical analysis.