Carcinomas of the jaws: report of a clear cell odontogenic carcinoma

Abstract

Odontogenic neoplasms composed entirely or predominantly of clear cells are exceptionally rare. They include the clear cell variant of calcifying epithelial odontogenic tumour (CEOT), ameloblastoma and clear cell odontogenic carcinoma. <h3>Case report</h3> A 71-year-old female presented with a well-defined, expansile lesion of the left posterior mandible. There was altered sensation of the lower lip. Radiographs demonstrated an ill-defined radiolucent lesion. Microscopic examination revealed an infiltrative tumour composed of follicles and trabeculae of large round cells with clear cytoplasm. The nuclei were small and ovoid with little pleomorphism and very occasional mitoses. The tumour cells were surrounded by reactive bony trabeculae. Immunohistochem-istry was equivocal. A provisional diagnosis of clear cell odontogenic carcinoma was made with a recommendation that metastatic tumours be excluded clinically. Chest, abdominal and pelvic CT scans and a full clinical, head and neck and dermatological examination failed to reveal any primary tumour. The patient underwent a hemi-mandibulectomy with subsequent reconstruction. <h3>Discussion</h3> Specific histological and immunohistochemical features to identify clear cell odontogenic carcinomas are still lacking and the diagnosis is made only after exclusion of other clear cell tumour entities. The aggressive potential of these neoplasms is well documented with almost 30% of patients dying of disease.