Fig. 46. The contents of an epithelial cyst and the consequences of an epithelial presence. A. The histologic section of this case of epithelial ingrowth demonstrates the presence of both a Soemmering's ring cataract and an epithelial inclusion cyst. Squamous epithelium desquamates surface cells as part of its renewal process. In this case, the cyst is filled with desquamated debris. The desquamated debris, if liberated into the anterior chamber, will evoke an extreme inflammatory reaction similar to that encountered with a ruptured dermoid cyst of orbital soft tissue. (Hematoxylin-eosin stain; × 10.) B. High magnification of the cyst wall shows that the epithelium has become differentiated. The desquamating surface is clearly differentiated from the more primitive-appearing basal cells. Degenerated surface cells will fill the cyst cavity. The underlying stroma of the iris, originally diaphanous in character, has become coarse and compact because of the influence of the invading epithelial cells.