A malignant teratoma is a type of cancer consisting of cysts that contain one or more of the three primary embryonic germ layers: ectoderm, mesoderm, and endoderm. Because malignant teratomas have usually spread by the time of diagnosis, systemic chemotherapy is needed. The prognosis for people with malignant teratomas is based on the size of the tumor, its location and the age of the patient.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.