Ocular surface choristomas. A, Limbal dermoid, clinical appearance. B, Higher magnification shows hairs emanating from the dermoid. C, Histology shows keratinized epithelium, dense stroma, and sebaceous glands with hair follicles (arrows). D, A lipodermoid differs from a dermoid in that it contains a significant amount of mature adipose tissue (A). This lipodermoid also contains dermal adnexal structures, including sebaceous glands (S) and hair follicles (H). E, Complex choristomas combine features of multiple types of choristomas, in this case osseous (O) and lipodermoid (L) choristomas.