Clear cell variant of calcifying epithelial odontogenic tumor (CEOT) in the maxilla: report of a case with immunohistochemical and ultrastructural investigations

Noncalcifying clear-cell variant of calcifying epithelial odontogenic tumor: A case report and review

Clear-cell tumors of the head and neck are biologically diverse consisting of benign, malignant and metastatic lesions. These tumors pose a diagnostic challenge. In the oral cavity, these may be derived from odontogenic/nonodontogenic epithelium or from mesenchyme or can be metastatic. Odontogenic tumors with clear-cell change are rare. Calcifying epithelial odontogenic tumor (CEOT) is a rare, benign, locally aggressive odontogenic epithelial tumor affecting the jaw. Here, we report a case of clear-cell variant of CEOT with its histopathological differential diagnosis. A 43-year-old male patient with swelling in his lower right back tooth region showed a well-defined radiolucent lesion with smooth corticated periphery on radiograph. On incisional biopsy, tumor showed small sheets, cords and islands of odontogenic epithelium with nests of clear cells with no evidence of calcification. A final diagnosis of CEOT was established by differentiating other odontogenic and nonodontogenic lesions on the basis of clinical, radiographic, histopathologic and special stain features.

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.

Odontogenic tumors: A review of 93 cases in the Vidharba region of Maharashtra

Background:

Tumors of the odontogenic origin (OTs) are rare tumors accounting for 1% of all the jaw tumors in the oral cavity. The behavior of these tumors ranges from hamartomatous proliferation to malignant neoplasm.

Aim:

The aim of this study was to determine the epidemiological data, clinical and histopathological picture with variants of the OTs diagnosed at our institute in the Vidarbha region.

Settings and Design:

A retrospective study was carried out with the permission from the institutional authorities. The archival records of the Department of Oral Pathology and Microbiology were reviewed.

Materials and Methods:

A total of 93 cases of OTs were reviewed retrospectively from the archival records of the Department of Oral Pathology and Microbiology from January 2008 to December 2018. Statistical analysis was carried out and the determination of the age, gender, jaw, site, diagnosis, variants and year-wise distribution of odontogenic lesions was taken out using the SPSS software.

Results:

Ninety-three cases of OTs were identified. The most common OT identified was ameloblastoma (n = 37/39.7%) followed by keratocystic OT (n = 8/8.6%), adenomatoid OT (n = 7/7.5%) and odontome (O) (n = 6/6.4%). The tumors were diagnosed in a wide age range from 1^st to 3^rd decennium of life. The mandibular posterior region was the most commonly affected anatomical site with the maxilla and mandible ratio of 1:6.

Conclusion:

OTs were found to be rare in the sample studied. The findings of the study were in concordance to those of Asian and African series. Variations were shown from the series of American reports, and further investigations are needed for this disparity.

A Rare Case of an Aggressive Clear Cell Variant of Calcifying Epithelial Odontogenic Tumor in the Posterior Maxilla

A clear cell variant of calcifying epithelial odontogenic tumor is a rare benign odontogenic neoplasm, accounting for 33 cases described in the literature. In this article, we report a challenging example of clear cell variant of calcifying epithelial odontogenic tumor of the posterior maxilla in a 45-year-old female patient showing locally aggressive growth and recurrence. Microscopically, islands of polyhedral cells containing abundant cytoplasm, well-developed intercellular bridges blended with clear cells were observed. The nuclei were frequently pleomorphic and permeated by hyaline calcified material. Immunohistochemistry revealed positivity for pan-cytokeratin (AE1/AE3), cytokeratins (CK-14 and CK-19), Bcl-2, p53, and p63. The Ki-67 proliferative index was ~10%. As odontogenic tumors are rare, when a significant clear cell component is observed, the differential diagnosis with other lesions of the jaws with similar morphology, including other odontogenic tumors with prominent clear cell component, clear cell odontogenic carcinomas, and metastatic tumors, is difficult.

Clear cell variant of calcifying epithelial odontogenic tumor: Case report with immunohistochemical findings

Calcifying epithelial odontogenic tumor (CEOT) is a rare benign odontogenic neoplasm, locally aggressive, characterized by sheets and nests of polyhedral epithelial cells exhibiting eosinophilic cytoplasm or less often clear cytoplasm. Additional features include nuclear pleomorphism without mitotic activity, concentric calcifications, and deposits of amyloid. Herein, we present an additional example of clear cell variant of CEOT occurring in a 25-year-old female. Microscopically, the tumor consisted on proliferation of epithelial cells with eosinophilic, clear vacuolated cytoplasm interspersed with focal areas of amyloid deposition. Tumor cells were immunopositive for AE1/AE3, CK14, CK19, β-catenin, CD138, and p63.

Key words:Calcifying epithelial odontogenic tumor, clear cell, histopathology, immunohistochemistry.

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 (Pindborg tumor) in the mandible

We present an uncommon case (female patient aged 59 years) of the clear-cell variant of calcifying epithelial odontogenic tumor (CEOT) (also known as Pindborg tumor) in the mandible. The clinical characteristics and probable origins of the clear tumor cells of previously reported cases of clear-cell variant of intraosseous CEOT are also summarized and discussed.

Biochemical and immunohistochemical characterization of the amyloid in canine amyloid-producing odontogenic tumor

The amyloid of canine amyloid-producing odontogenic tumor (APOT) was evaluated biochemically and immunohistochemically. The N-terminal amino-acid sequence of purified amyloid protein from a canine APOT was strikingly similar to the sequence in both rat ameloblastin and porcine sheathlin. Immunohistochemically, the amyloid in APOT from 9 dogs was strongly reactive with anti-rat ameloblastin, anti-porcine sheathlin, and anti-canine APOT amyloid and weakly reactive with anti-porcine amelogenin but negative for antibodies to cytokeratins, vimentin, desmin, alpha-smooth muscle actin, amyloid A, glial fibrillary acidic protein, or S100 protein. The neoplastic epithelial cells of APOT were focally reactive with antibodies to ameloblastin, sheathlin, amelogenin, and canine APOT amyloid. The similarity in amino-acid sequence of the amyloid protein of canine APOT to that of enamel proteins, such as ameloblastin, sheathlin, and amelogenin, and the expression of these antigens in both APOT amyloid and in the neoplastic cells suggest that the amyloid of canine APOT is derived from enamel proteins secreted by ameloblasts.

Clear cell variant of extraosseous calcifying epithelial odontogenic tumor: a case report

Calcifying epithelial odontogenic tumor (CEOT) is a benign epithelial odontogenic tumor occurring most frequently in the posterior part of the lower jaw. Extraosseous CEOT is one of the rarest forms of this tumor, and few such cases involving the maxillary gingiva have been reported in the literature. Here we present a case that showed progressive enlargement in the left maxillary gingival area over a period of 11 years. Clinical examination showed an ulcerated mass measuring 52 x 38 mm located adjacent to the lateral incisor and canine. Histologically, the tumor showed proliferation of sheets and cords of epithelial cells with granular, eosinophilic cytoplasm and round to oval nuclei. In other areas, the epithelial cells exhibited a clear, vacuolated cytoplasm and foci of eosinophilic, homogeneous material representing amyloid deposition. The present case of extraosseous CEOT with clear cells was considered to be a very rare form of this tumor.

Calcifying epithelial odontogenic tumor: an immunohistochemical case study

Calcifying epithelial odontogenic tumor (CEOT) is a rare benign odontogenic tumor. A case of CEOT in a 25-year-old female is presented here. Histologically, the case showed sheets of polyhedral epithelial cells with deep eosinophilic cytoplasm and prominent nuclei. Nuclear pleomorphism and hyperchromatism were evident. Globules of amyloid-like material among the tumor cells were prominent. Also found was a small area demonstrating a cribriform pattern. Immunohistochemical studies with antibodies against basement membrane proteins (laminins 1 and 5, collagen type IV and fibronectin), pan-cytokeratins AE1/AE3, vimentin, S-100 protein and CD 1a were performed. Tumor cells expressed laminins 1 and 5, fibronectin, cytokeratins and vimentin. The amyloid-like material was not reactive to all antibodies examined. A number of dendritic cells among sheets of tumor cells were revealed with strong staining for S-100 protein and CD 1a. These dendritic cells are likely to be Langerhans cells. Hence, immunohistochemistry is a useful method to study the variant of CEOT.

Cystic variant of calcifying epithelial odontogenic tumor

Calcifying epithelial odontogenic tumor (CEOT) is a benign, locally aggressive odontogenic neoplasm characterized by sheets and nests of epithelial cells with deeply eosinophilic or occasionally clear cytoplasm, calcifications, and eosinophilic amorphous material that stains positive for amyloid. Although many cases of CEOT are associated with impacted teeth and occasionally appear radiographically as dentigerous cysts, a true cystic variant has not been previously reported. We report a 15-year-old white male with a large cystic maxillary lesion that filled most of the left maxillary sinus. It deformed the medial wall, the inferior orbital floor, and caused narrowing of the left inferior meatus. Histologically, the cystic lining showed characteristics of CEOT. An intraluminal component that featured histologic characteristics of CEOT was identified during surgery. The lesion was enucleated and the postsurgical course of the patient was uneventful. Because follow-up has been for less than 1 year, a meaningful long-term prognosis cannot be determined at present. However, the patient has not reported any symptoms or signs of recurrence during the follow-up period.

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.

Immunohistochemical detection of hepatocyte growth factor, transforming growth factor-β and their receptors in epithelial odontogenic tumors

BACKGROUND

Tumors derived from odontogenic epithelium exhibit considerable variation and are classified into several benign and malignant entities. To clarify the role of growth factors in oncogenesis, cytodifferentiation and progression of epithelial odontogenic tumors, expression of hepatocyte growth factor (HGF), transforming growth factor-beta (TGF-beta) and their receptors were analyzed in these tumors as well as in tooth germs.

METHODS

Specimens of five tooth germs, 34 ameloblastomas, three calcifying epithelial odontogenic tumors (CEOTs), two clear cell odontogenic tumors (CCOTs), five adenomatoid odontogenic tumors (AOTs), six calcifying odontogenic cysts (COCs) and six malignant ameloblastomas were examined immunohistochemically with the use of antibodies against HGF, TGF-beta and their receptors.

RESULTS

In tooth germs and epithelial odontogenic tumors, immunoreactivity for HGF and TGF-beta was detected in both epithelial and mesenchymal cells, while expression of their receptors was found only in epithelial cells. In tooth germs and main types of ameloblastomas, HGF and TGF-beta reactivity was marked in epithelial cells near the basement membrane, and their receptors were diffusely positive in most epithelial cells. In subtypes of ameloblastomas, reduced expression of HGF, c-Met and TGF-beta and increased reactivity for TGF-beta receptors were detected in keratinizing cells in acanthomatous ameloblastomas, and granular cells in granular cell ameloblastomas demonstrated little or no expression of HGF, TGF-beta or their receptors. As compared with main types of ameloblastomas, basal cell ameloblastomas showed high HGF reactivity, and desmoplastic ameloblastomas exhibited elevated reactivity for TGF-beta and its receptors. Neoplastic cells in CEOTs, AOTs and COCs showed reactivity for HGF, TGF-beta and their receptors. Elevated HGF and TGF-beta reactivity was found in pseudoglandular cells in AOTs, and high expression of their receptors was noted in ghost cells in COCs. Metastasizing ameloblastomas showed similar expression patterns of HGF, TGF-beta and their receptors to those of benign ameloblastomas, while CCOTs and ameloblastic carcinomas had increased HGF expression and low reactivity for TGF-beta and its receptors as compared with benign ameloblastomas.

CONCLUSIONS

Immunohistochemical localization of HGF, TGF-beta and their receptors in tooth germs and epithelial odontogenic tumors supports the hypothesis that HGF and TGF-beta act on epithelial cells via paracrine and autocrine mechanisms. Altered expression of the agents in these epithelial odontogenic tumors, especially subtypes of ameloblastomas, AOTs and COCs, suggests that HGF and TGF-beta signaling might affect differentiation of neoplastic odontogenic epithelial cells. Activated HGF/c-Met pathway and reduced TGF-beta signaling in CCOTs and ameloblastic carcinomas may be associated with the malignant potential of these epithelial odontogenic tumors.

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.

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

Calcifying epithelial odontogenic tumor (CEOT) is an uncommon, locally aggressive odontogenic tumor representing less than 1% of all odontogenic tumors. Clear cells have been described in CEOT, ameloblastomas, calcifying odontogenic cysts, lateral periodontal, and gingival cysts. It is not yet clear if the clear cell variants of the odontogenic tumors have a different biologic behavior, even if it seems that these tumors are more aggressive with an higher recurrence rate. The authors present a case of a peripheral clear cell CEOT (CCCEOT). It is a rare lesion with only 9 cases reported in the literature. The lesion was removed by excision and no recurrence was found after a 4-year follow-up.

Calcifying epithelial odontogenic tumour: biological profile based on 181 cases from the literature

The present profile of the calcifying epithelial odontogenic tumour (CEOT) is based on a literature survey of 181 published tumour cases. The CEOT is a benign, though occasional locally invasive, slow-growing neoplasm occurring as intraosseous (94%) and extraosseous (6%) variants. The intraosseous type appears radiographically as an irregular, uni- or multilocular radiolucent area containing radiopaque masses which increases in size and opacity with time. Some 60% of intraosseous CEOT are associated with an unerupted tooth (or odontoma). CEOT shows a relative frequency of 1-2%. The extraosseous variant is diagnosed slightly earlier (mean age 34.4 years) than the intraosseous type (mean age 38.9 years). Both variants have an almost 1:1 gender ratio. The intraosseous CEOT shows a maxilla:mandible site ratio of 1:2 and are mainly located in the premolar/molar region. The present authors present evidence that the CEOT originates from the complex system of dental laminae or remnants thereof. Histologically, the CEOT is characterized by the occurrence of sheets, nests and masses of polyhedral, eosinophilic epithelial cells which may show cellular abnormalities including giant cell formation and nuclear pleomorphism. Some cells increase in size and produce a homogeneous, eosinophilic, 'amyloid-like' substance which may become calcified and which may be liberated as the cells break down. The true nature of the amyloid-like material is still unresolved. Histological variants including CEOT with cementum-like components, clear-cell CEOT (15 cases reported so far), CEOT-containing Langerhans' cells, combined epithelial odontogenic tumour (CEOT/AOT) and CEOT with myoepithelial cells are discussed in detail. In view of the relatively indolent biological behaviour of the CEOT, mutilating procedures, such as wide resection or hemisection of the mandible, seem unwarranted. Enucleation with a margin of macroscopically normal tissue is, therefore, the recommended treatment for CEOT involving the mandible. Maxillary CEOT should, however, be treated more aggressively, as they tend to grow more rapidly and do not usually remain well confined. Generally, recurrences are rare. Five years is considered the absolute minimum follow-up period. The survey has revealed only one well-documented case of a mandibular CEOT in a 75-year-old man showing features of malignancy.