Abstract :

  Introduction: Clear cell odontogenic carcinoma (CCOC) is a rare aggressive odontogenic tumor occurring mostly in the mandible in 5th–7th decades. It shows a female preponderance, capable of frequent recurrences and loco-regional and distant metastases.

  Case presentation: A 40 -year-old man with swelling in the area of left mandibular body and ascending ramus visited a dentist, and the patient's third molar was extracted with initial diagnosis of infection and abscess. Following extraction of the third Molar, the patient was referred to the oral and maxillofacial surgeon for continuous swelling and pain. In the panoramic view a multilocular radiolucent panoramic view a a multilocular radiolucent lesion with well-defined and partially corticated borders was evident . The lesion was removed partially and CCOC histopathologic features were observed in the microscopic view.

  Immunohistochemically, the tumor cells were positive for Pancytokeratin and Epithelial Membrane Antigen and negative for Vimentin, Smooth Musle Actin, HMB-45 and Desmin. S-100 staining was weakly positive. The patient did not return for further treatment and one year later there was no recurrence of swelling in the region.

  Conclusion: Due to histological similarities of this lesion with other clear cell lesions, differentiation

  From odontogenic tumors, salivary gland tumors and metastatic tumors, containing clear cells must be considered.