Calcifying epithelial odontogenic tumor of the maxilla (Pindborg tumor): surgical and immunohistochemical approach

Background Calcifying epithelial odontogenic tumor (CEOT) is a benign but locally aggressive epithelial odontogenic tumor that most commonly occurs in the mandible. Although the maxillary CEOT is rare, its biological behavior is indolent. Aim A comprehensive immunohistochemical study was performed concerning the local aggressive behavior of this tumor. Patients and methods In this study, 12 cases of patients who were attended in the outpatient clinic of the Oral and Maxillofacial Department, Faculty of Dentistry, Tanta University were included in this study after confirmed incisional biopsy of CEOT. The patients were examined clinically preoperative and aspiration test was done. After finishing the tumor resection, closure of the maxillary defect was done by double layer repair of the defect. Biopsy of this tumor was stained by the following markers p63, Ki67, type IV collagen, smooth muscle actin (SMA), CK19, CK5/6, S100 to study the biological behavior of the tumor. Results The neoplastic cells were diffusely cytoplasmic immunoreactive for CK19 and CK5/6. Also, the tumor cells showed mild to moderate staining to SMA. Weak intensity of collagen type IV was detected. The amyloid-like deposit was immunonegative for both SMA and type IV collagen. p63 was expressed in all studied cases. Strong to moderate nuclear staining to p63 was detected in the tumor cells. The Ki67 showed high proliferation activity of tumor cells differing from the benign tumor nature. Conclusion Maxillary CEOT tends to grow more rapidly and not be circumscribed, suggesting that more aggressive surgery is required in these specific cases.