Limbus-Sparing Congenital Central Corneal Dermoid: A Rare Developmental Anomaly.

Abstract

The authors report a rare case of a limbus-sparing central corneal dermoid in a 1-year-old boy, contributing to the limited existing literature of only three such documented cases worldwide. This case report describes the clinical presentation, surgical management, and histopathologic characteristics of this unique developmental anomaly. A comprehensive clinical evaluation was conducted, including ophthalmic examination, B-scan ultrasonography, and surgical intervention. The dermoid was excised along with penetrating keratoplasty, with the excised specimen undergoing detailed histopathologic and immunohistochemical analysis. Immunohistochemical markers including smooth muscle actin, CD34, vimentin, and p63 were examined to characterize the tissue composition. The patient presented with a 7.5 × 7.5 mm yellowish-brown hemispherical mass occupying the central cornea while sparing the limbus. Surgical exploration revealed full-thickness corneal involvement with corneoirido-lenticular adhesions. Histopathologic analysis demonstrated stratified squamous epithelium with surface keratinization and fibrocollagenous thickening. Immunohistochemistry revealed unexpected positive staining for both epithelial (p63) and mesenchymal (SMA, CD34, vimentin) stem cell markers, challenging previous understanding of central corneal dermoid cellular origins. This case represents an exceptionally rare presentation of a limbus-sparing central corneal dermoid, highlighting the complex embryological mechanisms underlying such developmental anomalies. Although surgical intervention was performed for cosmetic rehabilitation, the guarded prognosis and potential for complications necessitate careful patient counseling and long-term follow-up.