Most congenital tumors of the conjunctiva are choristomas, which are tumorous malformations composed of tissues not normally present at the involved site (1). A simple choristoma contains one type of tissue; a complex choristoma has more than one type. The main choristomatous tissues that occur in the conjunctiva include skin, bone, lacrimal gland, and cartilage. Most conjunctival choristomas are sporadic and nonhereditary. Both dermoid and dermolipoma are often part of Goldenhar’s syndrome, which also includes auricular and vertebral anolmalies. Dermoid is the second most common epibulbar choristoma, following dermolipoma (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17). In the authors’ clinical series of 1,643 conjunctival tumors, there were 10 dermoids, accounting for 25% of all epibulbar choristomas and for ,1% of all 1,643 lesions (2).

Small dermoids are often asymptomatic, but larger lesions can cause irritation, astigmatism, and inadequate eyelid closure (6,12). It appears as a variably sized, yellow-white limbal mass inferotemporally but it can appear in other meridians (2,3,4,5,6,7,8,9,10,11). It may range from 2 to 15 mm in diameter and 0 to 10 mm in thickness. Fine white hairs often protrude from the lesion. There is often a yellow-white lipid line in the adjacent corneal stroma. A conjunctival dermoid can show extensive corneal involvement with little involvement of the adjacent conjunctiva (13). It can rarely arise from the caruncle (14). An unusual variant (ring dermoid syndrome) is bilateral, straddles the corneoscleral limbus for 360 degrees and has an autosomal-dominant mode of inheritance (15).

Histopathologically, dermoid is lined by stratified squamous epithelium. Deep to the epithelium is dense collagenous tissue in which pilosebaceous units, sweat glands, and fat are often identifiable (2). In rare instances, bone can be present within the dermoid (complex choristoma) (16). It is possible that dermoid develops secondary to faulty eyelid fold closure embryologically with secondary entrapment of skin and mesenchyme.

Smaller asymptomatic dermoids can be observed and larger lesions may require excision (17). Reasons for surgical removal include amblyopia, secondary astigmatism, encroachment on the visual axis, dellen formation, inadequate eyelid closure, and cosmetic considerations. Early removal is advocated for symptomatic lesions to achieve a better cosmetic outcome. However, it is believed that early removal does little to change the astigmatism that was present preoperatively (12). Removal can be achieved by superficial shaving or by deeper excision with lamellar keratoplasty for deeper lesions (12,17).

Conjunctival dermoid can occur as an isolated lesion or it can be a component of Goldenhar syndrome.

Dermoids and related choristomas can assume a variety of configurations and management varies with the type and extent of the lesion.

Shields JA, Laibson PR, Augsburger JJ, Michon CA. Central corneal dermoid. A clinicopathologic correlation and review of the literature. Can J Ophthalmol 1986;21:23-26.

Sometimes an epibulbar dermoid is more atypical and can have other tissues in addition to dermal elements, meeting criteria for a complex choristoma. Epibulbar dermoid is also known to extend through the limbus into the anterior chamber.

Oakman JH, Lambert SR, Grossniklaus HE. Corneal dermoid: case report and review of classification. J Pediatr Ophthalmol Strabismus 1993;30:388-391.

In contrast to a dermoid, dermolipoma (lipodermoid) is less well defined and most often located in the superotemporal conjunctiva, often with extension posteriorly into the orbit (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18). It can occasionally be atypical and even pedunculated. Like dermoid, it is frequently associated with Goldenhar’s syndrome. It can also be a component of the organoid nevus syndrome (18). In the organoid nevus syndrome, the lesion usually has other heterotopic elements, most often cartilage and ectopic lacrimal gland tissue. Dermoid is the second most common epibulbar choristoma, following dermolipoma. In the authors’ clinical series of 1,643 conjunctival tumors, there were 23 dermolipomas, accounting for 58% of all epibulbar choristomas and for 1% of the 1,643 lesions (2).