Multicystic structures appearing in mature cystic teratomas of the ovary: an immunohistochemical and ultrastructural study.

Multicystic or sieve-like areas are frequently present in the walls of mature cystic ovarian teratomas. This histological, immunohistochemical and ultrastructural study supports the contention that such cysts arise from oleous material which has been extravasated through the cyst wall and become lodged within fibrous tissue and small blood vessels. Some cysts may also arise from degenerate sebaceous glands.