Clear cell Odontogenic Carcinoma Mandible Mimicking oral Cavity Squamous cell Carcinoma: An Intriguing case with Review of Literature

Clear cell odontogenic carcinoma (CCOC) is a rare odontogenic neoplasm with high risk of recurrence and aggressive behaviour. Presence of clear cells in head and neck is hallmark, but not pathognomic for the entity. Deceptive behaviour admist wide range of differentials, poses an immense diagnostic challenge. An incisional biopsy with appropriate immunohistochemistry is prudent for diagnosis. We herein report atypical case of CCOC mimicking squamous cell carcinoma, in a tertiary cancer center in North Eastern part of India.

Recurring Clear Cell Odontogenic Carcinoma Involving Vertebra and Pleura: A Case Report and Literature Review

Clear cell odontogenic carcinoma is a rare malignancy, which is vary in behavior from indolent tumor to cases with frequent recurrence and rare metastasis. In this manuscript, we report a case of clear cell odontogenic carcinoma of right lower mandible with cervical lymph node metastasis in a 50-year-old female. The tumor recurred and metastasized to vertebra and pleura after adjuvant radiation and chemotherapy, and the patient died of the disease 29 months after diagnosis. Pathologically, the tumor was composed of epithelial nests dominated by clear cells with ameloblastoma-like pattern and biphasic pattern. The tumor cells showed strong positive for AE1/AE3, KRT19, KRT5/6, P63, focal positive for KRT7, and weak positive for MUC1. Molecularly, EWSR1::ATF1 gene fusion was identified. To our knowledge, this report describes the first case of metastasis of clear cell odontogenic carcinoma involving regional lymph nodes and distant pleural and vertebral areas, demonstrating an aggressive clinical course of clear cell odontogenic carcinoma.

Unusual Presentation of Clear Cell Odontogenic Carcinoma: Case Report and Literature Review

Clear cell odontogenic carcinoma (CCOC) is a rare, aggressive epithelial neoplasm of the jaw first described in 1985 by Hansen and classified as an odontogenic malignant tumor in the 2005 WHO classification. To date, only 117 cases have been reported in the literature written in English. In this paper, we report the atypical presentation of a pericoronal localized tumor in the right mandibular wisdom tooth discovered during a routine radiologic examination. The patient, a 44-year-old healthy female, was referred by her general dental practitioner for examination of temporomandibular dysfunction and recurrent myofascial pain. Anamnesis and clinical examination did not suggest tumoral disease. The osteolytic lesion was removed, and histological examination revealed a clear cell odontogenic tumor (CCOT) of the right posterior lower jaw. Segmental lower jaw resection was performed, and a free iliac crest bone transplant was fixed with mandibular reconstruction plate. No cervical neck dissection was needed. A five-year follow-up examination shows excellent local and systemic recovery and no sign of tumor recurrence. The patient still suffers from bruxism and myofascial related pain, which are treated conservatively with a Michigan splint and physiotherapy. Based on this additional case, we review the literature and discuss the challenging diagnostic aspects, the unusual clinical presentation, and the treatment of CCOC.

Clear cell odontogenic carcinoma of maxilla: A rare case report

Clear cell odontogenic carcinoma is a rare, infrequent, aggressive in nature, locally reoccurring odontogenic tumor with a tendency of distant metastasis, occurring during to 4^th to 6^th decades with a mostly female predilection. Histologically, it is characterized by sheets and islands of vacuolated/clear cells. Till date, only 74 cases have been reported in the literature. We present a case of 45-year-old woman with a tumor mass extending from the maxillary right first premolar till the third molar region measuring 4 cm × 4 cm. The diagnosis was given based on the histopathological findings. Being locally aggressive, the reported data and understanding of this infrequent tumor needs to be strengthened by reporting new cases, and it also demands to be distinguished from other primary and metastatic clear cell tumors of the head-and-neck region.

A summary of 107 reported cases

The purpose of this study was to summarize the currently published cases of clear cell odontogenic carcinoma (CCOC). The PubMed and Springer databases were used to collect available reports, searching for 'clear cell odontogenic carcinoma', 'CCOC', or 'clear cell ameloblastoma'. The search resulted in 75 reports detailing 107 cases between 1985 and 2018. Clinically the tumor manifests as a swelling in the posterior mandible (n=46), anterior mandible (n=33), and maxilla (n=28). Radiological analysis of 85 cases typically showed a poorly defined expansive radiolucency (n=83). Of the 70 patients with symptoms reported, 44 specified a swelling, 11 tooth mobility, seven gingival/periodontal issues, five numbness, and three decreased jaw opening. One patient presented with a neck mass. The duration of symptoms prior to seeking care was specified for 52 patients: 2 months to 1 year for 34 patients, 1-2 years for seven, 2-4 years for two, 4-7 years for six, and 7-12 years for three. The incidence of recurrence appeared to be 38 of the 88 cases where recurrence was reported. CCOC can be distinguished from other oral cancers by its distinctive histology and immunohistochemical characteristics and less aggressive behavior. Currently, treatment should be early and aggressive resection with clear surgical margins and long-term follow-up. The overall goal is to collect a cohort of patients.

Clear cell odontogenic carcinoma: Case report of a deceptive pathology

Clear cells are associated with numerous physiological and pathological conditions. Odontogenic cysts and tumors can arise from physiological clear cells like rests of dental lamina. One such clear cell neoplasm is clear cell odontogenic carcinoma (CCOC) that is associated with aggressive clinical behavior, metastasis and low survival rate. With <80 cases reported so far, it is a rare entity. Initially described as a clear cell odontogenic tumor considering it as a benign but invasive neoplasm, it was later termed as CCOC owing to its infiltrative nature with a marked tendency for local recurrence, regional nodal spread and possible distant, mainly pulmonary, metastasis. Reported here is a case of CCOC affecting mandible of a 55-year-old female along with its immunohistochemical workup.

Peripheral clear cell variant of calcifying epithelial odontogenic tumor devoid of calcification

A clear cell variant of calcifying epithelial odontogenic tumor (CCEOT) affecting an extraosseous site is described. A 60-year-old male patient presented with gingival swelling on the lingual side of the anterior mandible. The results of biopsy suggested clear cell odontogenic carcinoma, and marginal resection of the mandible was performed. The resected specimen was composed of eosinophilic and clear cells with deposits of amyloid-like material. The clear cells exhibited granules that were positive for PAS. There was no calcification in the resected lesion. Based on these features, the conclusive diagnosis was peripheral CCEOT without calcification. No signs of recurrence were evident after 3 years of follow-up.

The role of computed tomography and magnetic resonance imaging in diagnosing clear cell ameloblastoma: A case report

Ameloblastoma is the most common and clinically relevant type of odontogenic tumor. Clear cell odontogenic carcinoma is histologically characterized by solid sheets and nests of clear cells, whereas clear cell ameloblastoma (CCAM) is histologically characterized by an ameloblastomatous component intermixed with an extensive clear cell component. A total of 12 reports have been published on the histological etiology for CCAM; however, no reports have made regarding the detailed computed tomography and/or magnetic resonance imaging features of tumors of this type. The present study describes a case of a well-circumscribed 20-mm radiolucent lesion of the anterior mandible that was misdiagnosed as a clear cell odontogenic carcinoma. The study describes the detailed radiological characteristics of a case of CCAM.

Clinical enigma: A rare case of clear cell odontogenic carcinoma

Clear cell odontogenic carcinoma is a rare, aggressive neoplasm of the jaw with only 74 reported cases. It occurs predominantly in the mandibular anterior region during fifth to seventh decades of life. Clinically it manifests as intra-bony swelling with a variable degree of pain. Microscopically, it reveals nests of cells with clear cytoplasm in connective tissue stroma arranged in different patterns. It is often misdiagnosed due to the rarity of lesion and confusing histopathology. Immunohistochemical staining plays an intricate role to uncertain the native of the clear cell to reach a confirmative diagnosis. The article aims to highlight the clinicopathologic features of clear cell odontogenic carcinoma in a middle-aged man with special emphasis on its differential diagnosis.

Cytomorphology and immunohistochemistry of a recurrent clear cell odontogenic carcinoma with molecular analysis: A case report with review of literature

Clear cell odontogenic carcinoma (CCOC) is a rare, odontogenic tumor of the jaws with mandibular involvement usually present in sixth decade of life with female preponderance. It is classified as a malignant tumor of odontogenic origin in 2005 by the World Health Organization because of its aggressive and destructive growth capacity and potential to metastasize. It needs to be distinguished from other primary and metastatic clear cell tumors of the oral and maxillofacial region. Recently, CCOCs have been noted to harbor a Ewing sarcoma breakpoint region 1 gene RNA-binding protein 1 (EWSR1) and activating transcription factor (ATF) gene translocation. To date, cytologic features of only one case have been reported in the literature. We report an additional case of 55-year-old woman with enlarging mass in the left mandible. This report describes cytologic and immunohistochemical features of CCOC with positive EWSR1 gene rearrangements by fluorescence in situ hybridization (FISH). As diagnosis of CCOC is challenging on fine-needle aspiration, immunohistochemistry and FISH analysis are very useful diagnostic tool in clear cell lesions of mandible.

Clear cell odontogenic carcinoma of maxilla: A case report and mini review

Clear cell odontogenic carcinoma is a rare odontogenic tumor occurring predominantly in posterior mandible during 5^th-7^th decades with a female predilection. It is a potentially aggressive tumor, capable of frequent recurrences and loco-regional and distant metastases. Till date, only 73 cases have been reported in the literature. Current case is of a 55-year-old woman with tumor mass extending from canine to molar region on the left maxillary arch. Being locally aggressive tumor with the capacity to metastasize, it demands to be distinguished from other primary and metastatic clear cell tumors of the oral and maxillofacial region. A brief compilation of the reported cases is being attempted in the current article to better understand the behavior of the tumor.

Clear cell carcinoma and clear cell odontogenic carcinoma: a comparative clinicopathologic and immunohistochemical study

Clear cell carcinoma or hyalinizing clear cell carcinoma (CCC) and clear cell odontogenic carcinoma (CCOC) are rare, low-grade and typically indolent malignancies that can be diagnostically challenging. In this study the clinicopathologic, histologic, and immunohistochemical features of 17 CCCs and 12 CCOCs are examined. The differential diagnosis of clear cell malignancies in the head and neck is discussed. The relationship of CCCs and CCOCs to other clear cell tumors on the basis of their immunohistochemical staining patterns is postulated.