Complex Palpebral Odontogenic Choristoma: A Reappraisal of the Origin of Teeth-bearing Periocular Lesions

Because of the variety of the ectopic tissues that were exhibited, a causative displacement of oral embryonic epithelium with extensive differentiating potentialities is posited. Two previously reported palpebral dental choristomas also had identical locations in the inferomedial eyelid. This is the site where the phakomatous choristoma may be encountered, but this unencapsulated mass creates an eyelid thickening without a globoid configuration and infiltrates the inferior orbit. After a careful re-appraisal of published reports of orbital cysts bearing a tooth that were formerly diagnosed as “teratomas,” we have concluded that they developed from similar embryonic oral (buccal) epithelial displacements rather than from aberrant germ cells, based on the cysts' linings and the associated accessory salivary glands in their walls. This view is further supported by the absence of heterologous teratomatous elements of endodermal or neuroectodermal derivation. A clinical and surgical approach to management and a new diagnostic schema for odontogenic choristomas are proposed.