Mixed germ cell tumour of the testis 1. Embryonal cell carcinoma. 2. Teratoma. 3. Seminoma. A testicular teratoma, unlike ovarian teratoma, is often aggressive in its biological behaviour, and often exists as part of testicular mixed germ cell tumours. Mature teratomas tend to be cystic with heterogeneous echoes in the fluid representing a mixture of mucinous or sebaceous material with or without hair follicles. Read more: http://radiopaedia.org/articles/testicular-teratoma
This shows an ovarian tumor, with teeth and a bone fragment inside, found in a Roman-age skeleton: Macroscopic view of the ovarian teratoma, with two teeth adhering to the inner surface. Two more teeth were found, along with a small bone fragment [Credit: ANTROPÒLEGS.LAB - UAB]
Calcified teratoma found in pelvis of Roman woman. Archaeologists working in the necropolis in Spain have found the 1,600-year-old remains of a Roman woman with a calcified tumor in her pelvis. The tumors come from germ cells, which form human eggs and can create hair, teeth and bone, among other structures. There are some really good pictures of the actual tumor on this website.