Teratomas are due to abnormal differentiation of germ cells during the embryonic period, but the exact mechanism is unknown, and there is also a correlation with genetic factors. Teratoma is not a product of pregnancy and is not associated with fertilization of the spermatozoon. It is essentially a tumor, mostly associated with mutations in the naive germ cells of the body. The main sites of involvement can involve the ovaries, testes, and even the mediastinum and retroperitoneum. Teratomas arise as a result of abnormal differentiation of human germ cells, but the exact pathogenesis is unclear. Unlike ordinary tumor cells, they continue to differentiate during proliferation and can produce tissues including, but not limited to, sebum, bone, hair, cartilage and even, eyeballs, teeth, muscle and brain. Although the composition of these tissues is more comprehensive, but its arrangement is very messy, does not have any functionality and biological activity, similar to teratoid so it is named. Some hereditary diseases, such as Turner’s syndrome and Kirschner’s syndrome, are prone to teratomas. Teratomas need to be removed and pathologically examined in order to determine whether the tumor is benign or malignant, so as to further deepen the treatment plan and avoid increasing health risks.