Expression of cytokeratins in epithelialized periapical lesions

This study attempted to clarify whether differential immunocytokeratin expression occurs in cystic and epithelialized noncystic lesions.

From January 2003 to June 2004, periapical surgery was carried out on 70 teeth, collecting 70 histologic samples. Serial sections of original histologic slices were prepared for immunostaining. The antibodies used were against cytokeratins CK7, AE1, AE3, AE1-3, and CAM52. The intensity of staining was evaluated as follows: 0 = no cells stained; 1 = weak staining (11%-25%); 2 = moderate staining (26%-75%); and 3 = intense staining (>or=76%).

Ten epithelized granulomas and 6 cysts were included. Intense staining was seen for AE1 and AE1-3 in the 2 types of lesion; staining with AE3 was moderate for epithelized granulomas and cysts. CK7 demonstrated a light reactivity in the outermost epithelial layer. CAM52 showed weak staining for the epithelized granuloma and moderate for the cyst.

Cysts and epithelized granulomas presented the same cytokeratin expression, though with marked differences in distribution and degree of staining of cytokeratins. This immunochemical technique is interesting for the determination of the histologic type and the prognosis, but may not be clinically practicable.