Tumors of the thymus and thymic region: III. Clinicopathological studies on teratomas and tumors of Germ Cell type.

In a series of 82 patients with tumors of the thymus and thymic region there were 11 with teratomas and germinal tumors. Four of these patients had benign cystic teratomas, 4 had malignant teratomas, 1 had an embryonal carcinoma, and 2 had seminomas. The benign teratomas were removed by simple extirpation without complications. The malignant teratomas were highly invasive, and despite extensive operations and postoperative radiotherapy, 3 of the 4 patients died within 9 months. One patient with predominantly seminomatous differentation of the teratoma was alive and well more than 3 years after the operation. The patient with an embryonal carcinoma died after 4 months. One of the 2 patients with seminoma remained alive 20 years after radical excision and postoperative radiotherapy. The other, who had a huge seminoma, died during operation. The prognosis in patients with seminomas or with predominantly seminomatous structures in teratomas seems to be good after combined radical excision and radiotherapy, although nonradical resection followed by raditherapy may be justified in high-risk patients.