Misdiagnosis of ameloblastoma in a patient with clear cell odontogenic carcinoma: a case report

Clear Cell Odontogenic Carcinoma: A Series of Three Cases

Background: Clear cell odontogenic carcinoma (CCOC) is a rare malignant odontogenic epithelial neoplasm of the jaws. It is composed of irregular nests of clear to faintly eosinophilic cells resembling clear cell rests of primitive dental lamina and an intermixed hyalinized fibrous stroma. Most cases occur in the 5th and 6th decades of life, with a female predominance. The mandible is affected more than the maxilla. Clinical features vary from asymptomatic to non-specific pain, ill-defined radiolucency, root resorption, and sometimes soft tissue extension. Histology varies from bland to high grade. CCOC demonstrated a significant tendency to recur. Metastasis typically involves regional lymph nodes, which haves been reported in 20–25% of cases. Pulmonary metastasis rarely occurs. Differential diagnoses are broad and include odontogenic, salivary, melanocytic, and metastatic neoplasia. CCOCs are positive for cytokeratins, mainly AE1/AE3 and CK19. Most cases show EWSR1 rearrangement and rarely, the BRAFV600E mutation. Design: Patient charts were reviewed at our institution. A total of three cases were found in electronic medical records, which were diagnosed as clear cell odontogenic carcinoma over a period of six years (2014–2019). Patient charts were reviewed for medical history and radiology data. The pathology slides were reviewed by one or more faculty members. Results: We present three cases of CCOC, ranging in age from 40 to 69 years (two women and one man). Two cases involved the maxilla and one involved the mandible. Two presented with painful swelling and one with mass recurrence. Radiography results show that two had poorly defined radiolucent lesions, and one was heterogeneous with a small nodule projecting into the maxillary sinus. Histological examination revealed an epithelial neoplasm composed of irregular sheets, cords, and nests of polygonal cells with central hyperchromatic, mildly pleomorphic nuclei surrounded by clear to pale eosinophilic cytoplasm, with occasional mitotic figures. The tumor had infiltrated the bone and soft tissues. Two cases were immunopositive for CK5/6 and one case was positive for p63 and CK19. Interestingly, the eosinophilic dentinoid matrix interspersed among tumor cells in one case was consistent with its odontogenic origin. Histochemical staining showed PAS-positive and diastase-labile intracytoplasmic material consistent with glycogen. Conclusion: Our study highlights the potential diagnostic significance of dentinoid (although reportedly seen in only 7% of cases), along with CK5/6 immunopositivity, in supporting the histologic diagnosis of CCOC among a variety of neoplasia in its differential diagnosis.

Clear Cell Odontogenic Carcinoma a Systematic Review

Clear cell Odontogenic Carcinoma (CCOC) is an uncommon malignant odontogenic tumor (MOT). It is the fifth most common MOT. A systematic review is presented of reported cases, case series and retrospective studies of CCOC, to determine trends in presentation, diagnostic features, treatment, and patient outcome. Searches of detailed databases were carried out to identify papers reporting CCOC. The variables were demographics, patient symptoms, tumor location, histopathological findings, immunohistochemical studies, treatment, follow-up, and recurrence. 117 cases were identified; CCOC was most frequently seen in mature females 65% (n = 76). The total average age was 55.4 with a range from 17 to 89 years, for females 56.4 and males 53.6 years. The mean size was 3.41 cm. The most common location was in the mandibular body 36.2% (n = 42), followed by the anterior mandible 23.3% (n = 27). The most common clinical presentation was a swelling 80.4% (n = 74), and the main symptom was pain 41.3% (n = 31), followed by painless lesion 24% (n = 18). The most common Immunohistochemistry positive expression was CK19, EMA, and CEA, and for special staining periodic acid Shiff (PAS); 97% of cases were treated surgically. The average follow-up was 30.3 months, and recurrence was reported in 52.4% of the cases. Conclusion: CCOC shows a strong predilection for the body and anterior mandible, and females are more frequently affected. CCOCs can be painful and the principle clinical sign is swelling, CCOCs can metastasize, and the prognosis is fair.

Rare clear cell odontogenic carcinoma associated with impacted tooth in a young patient: case report and literature review

Clear cell odontogenic carcinoma (CCOC) is a rare malignant odontogenic tumor. It is characterized by showing, on histopathological examination, clusters of vacuolated and clear tumor cells with epithelial differentiation surrounded by fibrocollagenous stroma and fibroblasts. The present study presents a rare clinical case of mandibular CCOC associated with an impacted tooth in a 26-year-old woman surgically treated with mandibulectomy and reconstruction with iliac crest bone graft. The patient has been followed up for 22 months without signs of recurrence. A search for case report/case series was carried out in the PUBMED database, as well as in the references of relevant previously published literature reviews. Ninety-six publications were identified, totaling 136 distinct cases reported. Female sex was the most affected (63.1%) with 63.3% of cases occurring in patients in the fifth, sixth, or seventh decades of life. The mandible was more affected than the maxilla (74.2%). Association of CCOC with impacted teeth was found in 2.4% of cases, thus rendering it a rare occurrence. The present case report corroborates the results of the survey regarding sex and anatomical location of the tumor; however, it contradicts the findings regarding age predilection. The case described is the fourth known occurrence of tooth impaction associated with the tumor and the first in a female. In conclusion, CCOC should be considered, as well as other malignancies, as a possible diagnosis of maxillary or mandibular intraosseous lesions even in unusual circumstances such as in association with impacted teeth and in young patients.