Congenital central corneal dermoid: A rare entity.

BACKGROUND:To understand the pathogenesis of a central corneal dermoid (CD) in a 12-day-old child, a comparison of CD specimen was done with limbal dermoid (LD) and cadaveric corneal (CC) specimens by immuno-histochemical staining. METHODS:The child underwent penetrating keratoplasty for visual rehabilitation. The corneal tissue was sent for histo-pathological and immunochemistry evaluation. The corneal specimen obtained was compared the origin of central CD with LD and CC based on their antigenic expression profile. RESULTS:Clinically over a period of 75 months post operatively the child maintained a clear graft. Hematoxylin and Eosin staining of LD had a typical morphology including stratified keratinized epithelium, hair shaft with pilo sebaceous glands, eccrine sweat glands, lymphocytes, and blood vessels. Immuno-histochemical staining showed positive stain for Cytokeratin 3 epithelial marker in the epithelium of CC, LD, and CD. Smooth muscle maker (SMA) was identified in LD and CD but not in the CC as it is devoid of blood vessels. Limbal stem cell maker (P63) was detected only in LD. Vimentin, a mesenchymal stem cell marker stained positively in all three tissues of CC, LD, and CD. CONCLUSIONS:Corneal dermoid showed positive staining for mesodermal tissue components compared to both ectodermal and mesodermal components in limbal dermoid suggesting possibly a different origin of corneal dermoid.