Peripheral clear cell calcifying epithelial odontogenic tumor. Report of a case

CEOT Variants or Entities: Time for a Rethink? A Case Series with Review of the Literature

The first detailed description of calcifying epithelial odontogenic tumor (CEOT) are ascribed to Jens Pindborg, but this tumor was described some years previously. Subsequently, CEOT was included in the 1971 WHO classification of odontogenic tumors and a since then number of variants have been described, which have added confusion to the diagnostic criteria. We aimed to survey the literature on the variants of CEOT, in parallel with a review of our single institution experience of CEOTs. Cases identified were collated, including available clinical, radiological and histological information and then reviewed, taking into account changes in the understanding and classifications of odontogenic tumors since initial diagnosis. We identified 26 cases from 1975 to 2017 for which histological material was available. Of these, only 13 (50%) showed the "classic" histological appearance, whilst two cases were identified as recognized variants. In 11 cases, other diagnoses or a differential diagnosis were preferred, with no agreed diagnosis in four of these. The proliferation fraction (Ki67) in the 10 cases tested was 2.1% ± 0.18. These findings illustrate the diagnostic challenges in this group of tumors and highlight the gaps in knowledge. Techniques, such as EWSR1 gene cytogenetic analysis, may be helpful in cases with clear cells. However, in other areas of controversy, including the non-calcifying and Langerhans cell rich variants, further investigation, perhaps utilizing sequencing technologies may be needed to refine the classification. Owing to the relative rarity of these lesions it would be beneficial if future work could be pursued as an international collaboration.

Is Conservative Surgery the Best Approach for Peripheral Calcifying Epithelial Odontogenic Tumors?

Background:

Peripheral Calcifying Epithelial Odontogenic Tumors (CEOT) rich in clear cells are a rare entity in the oral cavity, with only 14 previous case reports in the English literature. None have discussed recommended treatment approaches for extraosseous CEOT.

Objective:

This brief descriptive review describes a treatment approach for peripheral CEOT including the clear cell variant.

Study design:

A complete review of all well-documented extraosseous case reports with an emphasis on the treatment was performed. Additionally, the present article reports a case of a 21-year-old woman with an asymptomatic swelling in the gingiva finally diagnosed as peripheral CEOT abundant in clear cells.

Results:

Twenty-four cases of peripheral CEOT were described; conservative surgery was the first treatment approach in approximately 80% of cases, with only one recurrence.

Discussion:

Clear cell finding was not associated with more aggressive behavior.

Conclusion:

Conservative surgery may be an advantageous approach for this group of peripheral lesions with or without clear cells, with a recurrence rate of approximately 4%.

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.

Peripheral Clear Cell Variant of Calcifying Epithelial Odontogenic Tumor: Case Report and Review of the Literature

Calcifying epithelial odontogenic tumor (CEOT) is classified as an uncommon, benign, odontogenic neoplasm that is exclusively epithelial in origin. Of all reported cases, peripheral tumors account for 5-6 %, among which clear cell variants are still rare. A rare case of peripheral clear cell variant of CEOT occurring in the mandibular gingiva of a 47-year-old female is presented.

Clear cell cystic variant of calcifying epithelial odontogenic tumor

Calcifying epithelial odontogenic tumor (CEOT) is a solid, locally aggressive, benign odontogenic neoplasm characterized by sheets and nests of polyhedral epithelial cells exhibiting eosinophilic and less often clear cytoplasm, occasional nuclear pleomorphism without mitotic activity, calcifications, and deposits of amyloid. A cystic variant has been reported only twice. Herein, we present an additional example of cystic CEOT occurring in a 31-year-old male and featuring clear cell epithelial lining with deposits of amyloid and osteodentin.

Clear-cell variant of calcifying epithelial odontogenic tumor: clinical and radiographic characteristics

OBJECTIVES

Clear cells have been reported in approximately 8% of cases of calcifying epithelial odontogenic tumor (CEOT). The purpose of this study was to describe the clinical and radiographic features of clear-cell CEOT (CCEOT).

STUDY DESIGN

Eighteen cases of CCEOT were identified by review of the literature from 1958 to 2001, and a new one was added (total 19; 12 central, 7 peripheral).

RESULTS

Fourteen tumors (74%) were located in the mandible, with the central lesions favoring the posterior area and the peripheral lesions the anterior-bicuspid area. Radiographic features were as follows: 50% radiolucent, 50% mixed radiolucent-radiopaque; 92% unilocular; 64% well-defined noncorticated borders, 27% well-defined corticated borders, 9% irregular borders. Cortical perforation was common (67%) compared with CEOT without a clear-cell component (6.7%). Recurrence was reported in 17% of the central lesions and none of the peripheral ones.

CONCLUSIONS

CCEOT is a distinct variant of CEOT; its high tendency for cortical perforation may indicate a more aggressive behavior.

Peripheral clear cell variant of calcifying epithelial odontogenic tumor: Report of a case and immunohistochemical investigation

A case of peripheral calcifying epithelial odontogenic tumor, clear cell variant, located on the right gingival maxilla of a 48-year-old woman, presenting as a 2.0-cm solitary, firm nodule was studied. Microscopically, it was composed of polyhedral and clear epithelial cells associated with amyloid-like deposition. The clear epithelial cells exhibited granules that were positive for periodic acid-Schiff, and the amyloid-like deposit stained with Congo red showed a green birefringence in the polarized light. Polyhedral and clear epithelial cells were immunopositive for AE1/AE3 and cytokeratin 14. Immunoexpression of fibronectin and types I and III collagen were different between the amyloid-like deposits and the connective tissue stroma. Tenascin surrounded epithelial cells located inside the amyloid-like deposits. Laminin and type IV collagen were immunodetectable around the strands, cords, and nests of epithelial cells. This report represents the seventh case of peripheral calcifying epithelial odontogenic tumor, clear cell variant.

Calcifying epithelial odontogenic tumor showing microscopic features of potential malignant behavior

Calcifying epithelial odontogenic tumor (CEOT) is a rare benign, but locally aggressive, odontogenic tumor, and only 2 cases of malignant CEOT are reported in the literature. We describe a case of an atypical CEOT that penetrates the blood vessels, invades bone, and perforates the cortical plates of the mandible. On histologic examination, it shows marked pleomorphism and numerous mitotic figures, including a tripolar mitotic figure. Proliferating activity was found to be 5 times higher than typical CEOTs as demonstrated by the proliferating index, Ki-67, and analyzed by a computerized image analysis system. The Ki-67 labeling index of this case was also compared to various previously reported benign and malignant neoplasms. Although there is no clinical finding of metastasis, we believe this neoplasm has malignant potential on the basis of the histologic features of vascular invasion, significant mitotic activity, atypical mitotic figures, and an increased proliferating index.