Teratoma is a germ cell tumor made of all three germ layers. Because of that teratoma contains tissues and organs which are actually similar, if not the same, to normal tissues and organs. For example, a tumor may contain hair, teeth, bone. In rare cases even more complex organs such as eyes or hands can be found inside the tumor.
Teratoma can be made of one cyst or has within its capsule several fluid-filled cysts. These tumors are encapsulated and considered benign. However, there are several forms of the tumor which are known to act like malignant tumors.
Mature teratoma predominantly affects women (this is a benign tumor) while immature teratoma (malignant form of the tumor) generally occurs in men. More about Teratoma
Teratoma develops as a consequence of abnormal development of pluripotent germ cells and embryonic cells. The tumor is most commonly congenital (present at birth).
This tumor basically occurs in the testes or the ovaries. Teratomas originating from embryonic cells may form anywhere on the person's midline. For example, they can be found in the brain, skull, nose, under the tongue, in the neck, mediastinum, retroperitoneum and even hollow organs such as the stomach and bladder. Still, embryonic teratoma is in majority of cases located in the sacrococcygeal region and this very tumor represents the most common tumorous mass in new born babies.
Types of Teratoma
There are many hypothesis when it comes to teratomas. Also there are several teratomas which affect humans.
Mature teratoma of the mediastinum is classified as grade 0 teratoma. It may be of different structure, solid or cystic and even develop as the combination of the two. Mature teratoma may comprise different tissues (skin, muscle and bone tissue). Since the tumor is mature it is considered benign.
Dermoid cyst is a mature cystic tumor. It contains hair and other structures which normally derive from the ectoderm. Dermoid teratomas are often found in the skull sutures and ovaries.
Fetus in fetus and fetiform teratomas are not so common types of the tumor. They are also classified as mature teratomas. Inside the tumor there may be one or many components resembling an actual fetus.
Struma ovarii is rather rare mature teratoma which is made of thyroid tissue and localized in the ovary.
Pathology Classification of Teratomas
Teratomas are classified according to a cancer staging system. The grading system for this type of tumor includes 3 stages. If the tumor is graded 0, it is considered benign or mature. Grade 1 means that the tumor is immature and probably benign while grade 3 refers to immature, possibly malignant tumors. In case the tumor turns out to be malignant, it requires further staging and appropriate treatment.