Very rarely, the corpus luteum may form a cyst.

The laceration may also close up by itself, which can cause it to trap blood and potentially form a cyst or hematoma.

It then forms a cyst in the intermediate host's body.

Once inside a host insect, the larva penetrate the insect's gut and enter its body cavity and forms a cyst in the muscular or intestine region.

The glands in the mucosa of the duct will continue their secretions until the fluid forms a cyst or exit the duct via the opening in the foramen cecum.