Congenital solitary osseous choristoma of the left lateral canthus: a case report

An ocular osseous choristoma is a growth of mature, compact bone in the ocular or periocular soft tissue, and it is the rarest form of ocular choristoma, accounting for only 1.7% of all epibulbar choristomas.

Herein we present the case of a 20-month-old girl who was referred to the oculoplasty clinic with a progressively growing mass in the left lateral canthus. It had been present since birth without ocular involvement. Upon examination the mass was firm with a smooth surface, measured 9 × 6 × 3 mm, and exhibited no episcleral attachment or ocular involvement. An excisional biopsy was performed, and the histopathological findings were consistent with osseous choristoma of the left lateral canthus.

This report highlights the importance of considering osseous choristoma in the differential diagnosis of eyelid lesions, particularly those that have been present since birth. It also emphasizes the need for further studies investigating associations between osseous choristomas and ocular canthi.