Metastatic teratocarcinoma following chemotherapy. Maturation to a mass pathologically indistinguishable from a mediastinal enteric cyst.

A case of testicular teratocarcinoma metastatic to a mediastinal lymph node and associated with a mediastinal lesion indistinguishable from an enteric cyst is presented. It is postulated that the mediastinal enteric cyst-like lesion resulted from histologic maturation of metastatic teratocarcinoma after intensive chemotherapy. The basis in the medical literature for this postulate is detailed.