title: The characteristics of embryonal carcinoma cells in teratocarcinomas.
abstract: The orchiectomy specimens and the respective lymphadenectomies of 33 teratocarcinomas (teratoma and embryonal carcinoma) and 30 embryonal carcinomas were identified in a series of 457 consecutive germ cell tumors of the testis. Although teratocarcinomas were larger tumors the retroperitoneal lymphadenectomies revealed metastases in only 10 of 33 (30%) teratocarcinomas as compared to 19 of 30 (63%) embryonal carcinomas. Even after subtracting the teratoma component and stratifying for size of the embryonal carcinoma component, the teratocarcinomas were still less likely to metastasize than comparably sized pure embryonal carcinomas. Statistical significance was found between the differences in size and the differences in the rates of metastases, before and after stratifying for size of the embryonal carcinoma component of the teratocarcinomas. Further, all embryonal carcinomas metastasized as embryonal carcinoma while only 5 teratocarcinomas metastasized as embryonal carcinoma. This study supports experimental evidence that the embryonal carcinoma cells in teratocarcinomas are not necessarily identical to embryonal carcinoma cells in embryonal carcinomas.
mesh_terms: D000328:Adult; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D009373:Neoplasms, Germ Cell and Embryonal / Q000473:pathology*; D013724:Teratoma / Q000473:pathology*; D013736:Testicular Neoplasms / Q000473:pathology*