Exuberant vasculoconnective component in mediastinal mixed germ cell tumors

We aimed to evaluate the histologic components of primary mediastinal mixed germ cell tumors. A total of 221 patients diagnosed with a mediastinal germ cell tumor (GCT) were retrospectively reviewed. Among them, 14 patients underwent surgical resection after chemotherapy and 8 patients were diagnosed with mixed GCT, who were then selected for further evaluation. Clinical chart review and histologic review of biopsy and surgical specimens of 8 patients were performed. All 8 patients were young males and showed a mature teratoma or a mature teratoma with a focal immature teratoma in the resected specimens. Serum alpha-feto protein was variably elevated. Seven patients experienced an increase in tumor size after the chemotherapy. In 5 patients, a variable amount of vasculoconnective tissue was found along with the mature teratoma occupying average 66.3% of resected mass, and 3 of them showed an identical vasculoconnective component on biopsy before chemotherapy. We suggest that vasculoconnective tissue might be the intrinsic component of primary mediastinal mixed GCT. When vasculoconnective tissue is obtained on small biopsy of an anterior mediastinal mass of a young male, the possibility of underlying mixed GCT should be considered and further clinical work up should be performed.