Abstract
Purpose::
Dermoid cysts are rare, congenital benign tumors (histologically defined as choristoma) that often consist of a combination of ectodermal elements including keratinized epithelium, sebaceous glands, and hair and mesodermal elements including fibrous tissues, vessels, and fat. To elucidate its histopathological status, we investigated the expression patterns of specific epithelial proteins in a dermoid cyst of the ocular surface.
Methods::
Samples enrolled in this study were 10 limbal dermoid tissues, 3 normal conjunctival tissues, 3 normal skin tissues, and 5 normal corneas. For these tissues, immunohistochemical examination was performed employing antibodies directed against cytokeratins 1, 4, 8, 10, 12, 13, 14, 15, 18, and 19 as well as keratinization-related proteins including transglutaminase 1, involucrin, loricrin, filaggrin, and SPRR2. Also, to reveal whether the dermoid tissue is embryologically committed to the ocular compartment, immunolocalization of the Pax6 protein was studied.
Results::
The cytokeratin expression pattern of the limbal dermoid tissues was similar to that of normal conjunctival tissues rather than skin tissues and corneas. However, their expression pattern of the keratinization-related proteins was similar to that of skin tissues rather than conjunctival tissues and corneas. Pax6 expression was detected in the limbal dermoid tissues as well as conjunctival tissues and corneas, but not detected in normal skin tissues.
Conclusions::
The epithelial part of limbal dermoid tissue is likely to have similar cellular features as conjunctival epithelium from the view of cytokeratin and Pax6 expression, while keratinization status implies that this tissue has similar cellular features as skin epidermis.
Keywords: immunohistochemistry • cornea: epithelium • tumors