Ovary, Immature Teratoma

Immature teratomas, one of the most common malignant ovarian germ cell tumours, are typically seen in prepubertal and young adult patients. Grossly, these tumours tend to be soft and show a fleshy cut surface. Cystic areas may also be identified, in addition to more traditional mature teratomatous elements. Microscopically, components from all three germ cell layers are identified with a variable mixture of both mature and immature tissue. Immature neuroepithelium is the most commonly identified primitive tissue. Grading of these neoplasms is traditionally based on a semiquantitative scoring system which evaluates the amount of immature neuroepithelium present in any one slide (graded I-III), however a two-tiered approach (high grade or low grade) is also used. Treatment is based on tumour grade as well as clinicopathologic stage.