Mature cystic teratoma of the appendix: a case report.

Background: Teratomas very rarely arise from the appendix. To our knowledge, only one prior case of mature teratoma involving the appendix has been reported in the medical literature.

Case: Our case is the second reported case of mature cystic teratoma involving the appendix, and, to our knowledge, it is the first reported in a female who had two simultaneous teratomas, one arising from the appendix and one arising from the right ovary.

Conclusion: Although mature cystic teratoma is a rare tumor of the appendix, it should be considered in the differential diagnosis of appendiceal masses. The differential diagnosis of appendiceal masses, including clinical and pathologic features, is discussed in detail.