Ahmed Nabil Fahmi, Hanan Eid, Amr H. Gibaly And Mohamed Mostafa Elshamaa,

ABSTRACT
Dermoid Cysts Are Soft Tissue Cysts Of Embryonic Origin That Arise Along Lines Of Skin Fusion. They Formed Due To Abnormal Ectodermal Sequestration During Early Embryological Life. The Variable Types Of Craniofacial Dermoid Cysts May Be Related To The Initial Position Of Ectodermal Inclusion Within The Underlying Mesoderm. Variations In The Degree Of Ectodermal Inclusion Result In Differences In The Histology And Structure Of Dermoid Cysts At The Various Craniofacial Sites. Such Histologic Differences May Directly Influence The Severity Of Clinical Presentation. Five Cases Of Periorbital And Submental Dermoid Cysts Were Operated On Under General Anesthesia; All Cases Were Subjected To Immunohistochemical Staining With Cytokeratin, Vimentin And Chromogranin. There Was Significant Correlation Between The Expression Of Chromogranin In Periorbital And Submental Dermoid Cysts (P=0.007), While There Was Nonsignificant Correlation Between The Expression Of Cytokeratin In The Two Lesions (P= 0.08) And Also Nonsignificant Correlation Between The Expression Of Vimentin In The Two Lesions (P=0.43). Objective To Differentiate Histologically And By Using Immunohistochemitry Between Submental And Periorbital Dermoid Cysts.