Adenomatoid odontogenic tumor associated with calcifying epithelial odontogenic tumor

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.

A Combined Epithelial Odontogenic Tumor? A 7-Year Follow-Up Case

Adenomatoid odontogenic tumor (AOT) is a benign epithelial odontogenic tumor characterized by slow and progressive growth. When central lesions are associated with an unerupted permanent tooth, they are also known as the follicular type. Histological variants of AOT may complicate diagnosis with possible adverse effects on treatment and prognosis. The aim of this study is to report a case of a follicular AOT with extensive calcifying epithelial odontogenic tumor (CEOT)-like histopathological areas in the anterior region of the mandible that was treated by enucleation. The teeth displaced by the tumor were repositioned with orthodontic treatment, and after 7 years of follow-up, the bone trabeculae were normal with no evidence of recurrence. The clinical, radiographic and histopathologic aspects of these tumors are discussed and the debate surrounding whether these cases are true combined lesions or histologic variants of the primary tumor is raised.

The adenomatoid odontogenic tumour: an update of selected issues

The aim of this update was to present the recent notable progress within remaining questions relating to the adenomatoid odontogenic tumour (AOT). Selected issues that were studied included the following: (i) AOT history and terminology, (ii) the so-called peripheral AOT, (iii) AOT and the gubernaculum dentis and (iv) the so-called adenomatoid odontogenic cyst (AOC). The earliest irrefutable European case of AOT was described in 1915 by Harbitz as 'cystic adamantoma'. Recently, Ide et al. have traced two Japanese cases with irrefutable proof described by Nakayama in 1903. The so-called peripheral (gingival) variant of AOT seems to cover a dual pathogenesis, both an 'erupted intraosseous' and an 'extraosseous' (gingival) one. In 1992, we theorized that the generally unnoticed gubernaculum dentis (cord and canal) seems to be involved in the development of AOT. Ide et al. have concluded that the dental lamina in the gubernacular cord seems to be an embryonic source of the vast majority of AOTs. The suggestion by Marx and Stern to change the nomenclature of AOT to adenomatoid odontogenic cyst (AOC) is critically discussed. The present authors agree on the background of the work of several groups of researchers and WHO/IARC classifications that the biology of the follicular variant of AOT is already fully explained and does not make room for any change in diagnostic terms. Further, there is no reason to change terminology in this case where improvements or conditions to better clinical management are not an issue.

Case Presentation of Concomitant and Contiguous Adenomatoid Odontogenic Tumor and Focal Cemento-Ossifying Dysplasia

A 24 year-old male was presented for the diagnosis of an asymptomatic bony expansion in relation to the right maxillary canine and first premolar. The unilocular radiolucent lesion with central foci of calcification had caused divergence of canine and first premolar roots without any resorption. This case report details a diagnosis of two distinct disease processes of different cellular origin namely, focal cemento-ossifying dysplasia and adenomatoid odontogenic tumor in a previously unreported concomitant and contiguous relationship. The diagnosis was determined by a combination of clinical, radiographic, histopathological and surgical evidence. This case highlights two points, first the need to examine all mixed radiolucent-radiopaque lesions with advanced imaging techniques to assess the number and extent of the lesions prior to treatment planning. Second a likely role of periodontal ligament as the tissue source for odontogenic epithelial cells and mesenchymal stem cells required for the development of odontogenic tumors and cemento-osseous dysplasias.

Adenoid ameloblastoma: clinicopathologic description of five cases and systematic review of the current knowledge

OBJECTIVE

To describe the clinicopathologic and immunohistochemical features of five cases of adenoid ameloblastoma.

STUDY DESIGN

Clinicopathologic data were gathered from medical records and compared with those compiled from a systematic review. Slides were also immunohistochemically stained for Ki-67, p16, p53, and cytokeratins (7, 8, 14, 18, and 19).

RESULTS

There were 3 males (60%) and 2 (40%) females. The mean age was 44 ± 10 years. Of the five adenoid ameloblastomas, 4 (80%) occurred in the posterior maxilla. Patients typically complained of asymptomatic swelling. All patients received surgical resection as primary therapy; 1 (20%) patient also received adjuvant radiotherapy. Recurrence was diagnosed in all patients. Immunohistochemically, the tumors stained focally positive for CK7, 8, 14, and 18 and diffusely positive for CK-19, p16, and p53. The mean Ki-67-positive cells were 72.4 ± 24.9 positive cells per high-power field (range 53-111).

CONCLUSIONS

To our knowledge, this is the largest series of adenoid ameloblastoma reported in the literature. Our data suggest that this entity demonstrates aggressive behavior characterized by a high likelihood of recurrence.

A rare case of hybrid odontogenic tumor: Calcifying epithelial odontogenic tumor combined with ameloblastoma

A hybrid odontogenic tumor comprising two distinct lesions is extremely rare. Nevertheless, such tumors have been reported in the literature for academic and research interest. However, it is still obscure whether they behave as a new entity or they solely present separate histopathologic patterns. Here, we present a true hybrid neoplasm of combined ameloblastoma and calcifying epithelial odontogenic tumor showing intermixed histopathologic patterns of both the tumors.

Report of Two Cases of Combined Odontogenic Tumors: Ameloblastoma with Odontogenic Keratocyst and Ameloblastic Fibroma with Calcifying Odontogenic Cyst

Combined odontogenic neoplasms have rarely been documented. Such tumors have also been described by other researchers as "hybrid" lesions. The histologic features are often identical to other individually well-established odontogenic neoplasms such as ameloblastoma, adenomatoid odontogenic tumor, ameloblastic fibroma (AF), and ameloblastic fibro-odontoma. Their clinical presentation is variable, ranging from cysts to neoplasms showing varying degrees of aggressive behavior. Most combined tumors contain features of one of the odontogenic tumors in combination with either a calcifying odontogenic cyst (COC) or a calcifying epithelial odontogenic tumor. We present two new cases of combined odontogenic tumors: an ameloblastoma with an odontogenic keratocyst and an AF with COC. Predicting clinical outcome is challenging when a combination tumor is encountered due to the paucity of such lesions. One must understand salient features of these entities and differentiate them from the more common conventional neoplasms to expand classification and provide prognostic criteria.

Development and growth of adenomatoid odontogenic tumor related to formation and eruption of teeth

The number of published cases of adenomatoid odontogenic tumor (AOT) has steadily increased, and about half were reported in Asian populations. Although the clinicopathologic profile of AOT has been extensively reported, factual knowledge of its pathogenesis is rudimentary at best, and there is controversy as to precisely which odontogenic epithelium it arises from. AOT is a successional tooth-associated lesion which develops during the mixed dentition. The permanent successor differs from its deciduous predecessor in that it has an eruptive pathway from the dental follicle to the gingiva, the gubernaculum dentis. With this background in mind, the present review focuses mainly on the early development of AOT. We successfully demonstrated a close spatial relationship between AOT and the gubernaculum dentis in a typical case. From further observations of the same AOT in which an enclosed permanent canine showed enamel hypoplasia, it is possible to pinpoint areas around the crown of a developing successional tooth in continuity with the gubernaculum dentis as starting points. In addition, we discuss the unifying histogenetic concept of three clinical variants, namely, pericoronal (follicular), extracoronal (extrafollicular), (see Article note) and peripheral.

An updated clinical and epidemiological profile of the adenomatoid odontogenic tumour: a collaborative retrospective study

BACKGROUND

Adenomatoid odontogenic tumour (AOT) is a benign odontogenic jaw lesion. The aim of this study was to update the biological profile of AOT.

MATERIAL AND METHODS

Cases published in the literature and cases in files of co-authors were included.

RESULTS

550 new cases were retrieved, and of a total of 1082 cases analysed, 87.2% were found in the second and third decades. The M:F ratio was 1:1.9. 70.8% were of the follicular variant (extrafollicular: 26.9%, peripheral: 2.3%). 64.3% occurred in the maxilla. 60% of follicular AOTs were associated with unerupted canines. Nineteen cases of AOT (2.8%, M:F ratio was 1:1.4) were associated with embedded third molars. Twenty-two peripheral AOTs (2.3%, M:F ratio was 1:5.3) were recorded. The relative frequency (RF) of AOT ranged between 0.6% and 38.5%, revealing a considerably wider AOT/RF range than hitherto reported (2.2-7.1%).

CONCLUSIONS

This updated review based on the largest number of AOT cases ever presented, confirms the distinctive, although not pathognomonic clinicopathological profile of the AOT, its worldwide occurrence, and its consistently benign behaviour.

Adenomatoid odontogenic tumour in a 12-year-old boy

We present a rare finding of adenomatoid odontogenic tumour (AOT) in a 12-year-old boy who was referred to the Department of Paediatric Dentistry at the Eastman Dental Hospital for the extraction of a carious maxillary permanent molar. First presentation revealed that the maxillary right permanent lateral incisor and canine were unerupted. Radiological examination revealed a circumscribed radiolucent area associated with the distal aspect of the maxillary right permanent lateral incisor. The patient was admitted to our Day Care Unit where the carious maxillary molar was extracted and the radiolucent area associated with the maxillary right permanent incisor was explored. Pathological examination confirmed the lesion as adenomatoid odontogenic tumour. We present a brief review of the literature and consider how differential diagnosis of this tumour from more common odontogenic lesions can be established.

Clear cell variant of calcifying epithelial odontogenic tumor: case report and review of the literature

The calcifying epithelial odontogenic tumor (CEOT) is a rare benign odontogenic neoplasm which was first described by Pindborg in 1955 and accounts for less than 1% of all odontogenic lesions. Recently, a clear cell variant of CEOT has been identified with only eight well-documented cases in the literature. We present an additional case of clear cell CEOT of the mandible and review the salient clinical, radiologic, and histopathologic features of this entity and CEOTs in general. The differential diagnosis of clear cell tumors in the mandible includes: clear cell odontogenic tumor, clear cell ameloblastoma (odontogenic carcinoma), metastatic clear cell adenocarcinoma, primary intraosseous mucoepidermoid carcinoma, acinic cell carcinoma, epithelial-myoepithelial carcinoma, clear cell salivary gland tumors, and clear cell variant of squamous cell carcinoma. Because of the belief that clear cell odontogenic tumors are locally aggressive neoplasms, definitive resection of the entire mass with tumor-free surgical margins and long-term follow-up are recommended.

Adenomatoid odontogenic tumour with features of calcifying epithelial odontogenic tumour. (The so-called combined epithelial odontogenic tumour.) Clinico-pathological report of 12 cases

The combination of two odontogenic tumours is a rarely reported finding. To date only 10 cases of adenomatoid odontogenic tumour (AOT) combined with areas of calcifying epithelial odontogenic tumour (CEOT) have been published. This article describes the clinical, radiographical and microscopic findings of 12 cases of AOT, in which CEOT-like areas of variable sizes were found. These results suggest that such areas may be considered as a normal feature within the histomorphological spectrum of AOT.

Variants of the adenomatoid odontogenic tumor with a note on tumor origin

Three rare variants of the adenomatoid odontogenic tumor (AOT) are described. A follicular AOT associated with an impacted and displaced 28, an extra-follicular variant mimicking a radicular cyst around the apex of 23 and a peripheral (epulis-like) variant exhibiting a periodontal bone defect palatal to 21. On reappraisal of the origin and pathogenesis of the AOT, it would seem that this tumor or hamartomatous lesion is derived from odontogenic epithelium of the dental lamina complex or its remnants.

The combined epithelial odontogenic tumour in Malaysians

The combined epithelial odontogenic tumour represents a hybrid lesion comprising primarily areas of adenomatoid odontogenic tumour intermixed with foci of calcifying epithelial odontogenic tumour. Five such cases retrieved from the files of the Division of Stomatology, Institute for Medical Research, Kuala Lumpur, and four others from the existing literature were analysed. A mean age of 18.8 years, a female preponderance (66.7%) with a male to female ratio of 1:2 and predilection for the mandible (55.6%) were observed. All cases were treated by conservative surgery and the lack of recurrence confirmed the innocuous nature of this lesion.

Adenomatoid odontogenic tumor: biologic profile based on 499 cases

Topographically, the AOT occurs in peripheral and central variants, the latter further in follicular (with embedded tooth) and extrafollicular (no embedded tooth) types. The AOT is slow growing with few or no symptoms. Tumor growth may cause displacement of teeth rather than root resorption. The follicular AOT mimics a follicular cyst, the extrafollicular a residual or "globulo-maxillary" cyst and the peripheral a gingival fibroma. All variants of AOT show identical histologic features. The central variants account for 97.2%, 73.0% of which are follicular. The follicular variant (M:F ratio 1 to 1.9) is three times as frequent as the extrafollicular. The follicular variant is diagnosed earlier in life (mean age 17 yr) than the extrafollicular (mean age 24 yr). 53.1% of all variants occur within the teens (13-19 yr). Follicular AOT is associated with one embedded tooth in 93.2%. Maxillary permanent canines account for 41.7% and all four canines for 60.1% of AOT-associated embedded teeth. Ranking four among the odontogenic tumors the AOT is not a particularly rare tumor. Conservative surgical excision is the treatment of choice. Documented recurrences have not been reported.