Pathogenesis of balls in mature ovarian cystic teratoma. Report of 3 cases and review of literature.

Ovarian cystic teratomas with intracystic balls are rare, and only 11 cases have been reported since 1946. We present 2 new cases and review the literature for the clinical presentation and morphological appearances of the cysts and balls. We also present our histology findings on a third case reported in the international literature. The pathogenesis of balls formation is unknown. We put forward a hypothesis based on the forces which control the production and absorption of the intracystic contents and also recommendations for investigators who may encounter this lesion. We believe that predominance of large secretory and absorptive rather than exfoliative surfaces lining the cysts would favor the absorption of most of the contents into the general circulation, leaving the remaining material to solidify and mould into balls. Still, however, there are many unanswered questions.