Clear cell odontogenic carcinoma. A review.

INTRODUCTION: Clear cell odontogenic carcinoma (CCOC) is described as an exceptional and hard to diagnose malignant tumor which was first reported by Hansen in 1985. The purpose of this review article is to show that CCOC is a not that rare entity and to discuss its various aspects in order to enhance the diagnosis. MATERIAL AND METHODS: A search in the English language literature was performed using the Scopus, ScienceDirect, PubMed and Medline databases between 1985 and 2016. Data were collected on epidemiologic, clinical, radiographic, histological, immunohistochemistrical, cytogenetic, management, follow-up and prognosis features of CCOC. RESULTS: Sixty-five studies from which a total of 95 case reports were included in the review. CCOC was generally seen in the fifth decade and the most common site was mandibular. The most frequently found symptoms were swelling, tooth mobility and pain. Radiologically, the image was radiolucent and could look like a cyst or a periodontal lesion. In situ hybridization techniques frequently expressed a gene fission of EWSR1. The treatment was mostly a radical surgical excision of the tumor with or without adjuvant radiotherapy or chemotherapy. CCOC showed high rates of recurrence and mortality related with the presence of distance metastasis. DISCUSSION: Fission of EWSR1 gene could be the main element it the diagnosis of CCOC. A multidisciplinary approach, including a radiologist, pathologist and an oral & maxillofacial surgeon may be helpful in the evaluation and management of these lesions. With 95 reports found in English literature, we cannot say that CCOC is extremely rare anymore.

Clear cell odontogenic carcinoma, diagnostic difficulties. A case report.

INTRODUCTION: Clear cell odontogenic carcinoma (COCC) is a rare tumor described by Hansen et al. in 1985. The clinical and radiological manifestations are multiple and the diagnosis is histological. OBSERVATION: A 64-year-old patient consulted us for a right mandibular osteolytic lesion associated to a homolateral labial hypoesthesia. A biopsy was performed under local anesthesia. Histology was consistent with a metastatic lesion of clear kidney cell carcinoma, COCC, or odontogenic squamous tumor. Additional tests eliminated a metastatic lesion. A wide excision of the lesion by hemi-mandibulectomy associated with lymph node dissection and reconstruction by a fibula osteoseptocutaneous flap was performed. Presence of a fission of the EWSR1 gene on the histological examination of the surgical specimen made the diagnosis of COCC. DISCUSSION: Our observation illustrates the difficulty of diagnosing COCC. The new contribution of the cytogenetic techniques such as FISH-type techniques makes possible the improvement of the diagnosis.