Expansile keratocystic odontogenic tumor in the maxilla: immunohistochemical studies and review of literature
A 54-year-old man visited for evaluation after sustaining unilateral facial swelling. Following the radiological examination, large expanded intrabony cystic lesion was found in the left maxilla and maxillary sinus. The lesion occupied the entire unilateral maxilla and maxillary sinus with the expansion and erosion of cortical bone. Tooth displacement was not detected, but some root resorption was observed in the teeth involved.() Benign cystic lesion much like KCOT was diagnosed due to its radiological and clinical features and was completely excised with Weber-Ferguson incision. The patient had been followed up for 2 years without any evidence of recurrence.()\nThe histopathological feature of H&E-stained slide was similar to that of case 1, with thin-lining epithelium and parakeratinized luminal surface as demonstrating features of KCOT. Immunohistochemical analysis of the tumor specimen was performed as described previously with case 1. Strong expression of p53 and p63, positive but weak detections of BCL2 and Ki-67, and negative detection of BAX were observed, and these expression patterns were similar to those of case 1.(, )