What is the distinguishing characteristic of dysgerminoma?

Dysgerminoma is a type of germ cell tumor commonly found in the ovary and has specific histological features that distinguish it from other ovarian neoplasms. The defining characteristic of dysgerminoma is that it is composed of large polyhedral (or polygonal) cells with abundant cytoplasm and large nuclei. These characteristics are crucial for pathologists to identify dysgerminomas under the microscope.

The presence of these large, well-defined cells, along with the tumor's typical lymphocytic infiltration, helps differentiate dysgerminoma from other types of ovarian tumors. This histological feature is critical for diagnosing the tumor and understanding its origin and behavior.

In addition to the cellular structure, dysgerminoma is typically found in younger women, particularly those in their late teens to early thirties, rather than postmenopausal women, further elucidating why this characterization is significant. The other options mentioned do not accurately reflect the typical features or associations of dysgerminoma.