Benign Epithelial Odontogenic Tumor Research Articles

Adenoid Ameloblastoma- A very rare, odontogenic tumor variant with less than 20 reported cases in the literature: Report of two cases and literature review

Abstract Introduction/Objective We describe two cases of Adenoid Ameloblastoma (AA), a very rare, hybrid variant, of two of the most common odontogenic neoplasms (Ameloblastoma and adenomatoid odontogenic tumors). AA is a benign epithelial odontogenic tumor characterized microscopically by epithelium resembling conventional ameloblastoma, with additional duct-like structures, epithelial whorls, and cribriform architecture. Dentinoid deposits, clusters of clear cells, and ghost-cell keratinization may also be present. These tumors do not harbor BRAF or KRAS mutations and their molecular basis appears distinct from conventional ameloblastoma but remains unknown. The lesion tends to recur, and sometimes, only correctly diagnosed after recurrence. Methods/Case Report Adenoid Ameloblastomas were identified after a review of the Temple University, Department of Pathology archive from 2012-2022. A total of four specimens (two patients) were identified. Results (if a Case Study enter NA) Case# 1 22-years-old female Biopsy Location/ size: Mandible, left, 2.1 cm. Microscopic: Neoplastic proliferation composed of odontogenic epithelium in a plexiform pattern with the formation of pseudo glandular structures of variably sized cystic spaces, the peripheral epithelial cells are palisaded with reversed polarity. The central cells have clear cytoplasm and resemble stellate reticulum with occasional tight whorls of cells noted. Hemorrhage and giant cells are present in granulation tissue. The lesion was incompletely excised. Diagnosis: Benign odontogenic tumor. Case#2 (1st occurrence): -49-years-old male -Biopsy -Location and size of lesion: Maxilla-left anterior, 0.9 cm. -Microscopic: Cyst lined by loosely arranged epithelial cells with a basal cell layer having hyperchromatic and palisaded nuclei. Knots of squamous cells are present within the cyst lining. The luminal layer is flattened to cuboidal and nonkeratinized. Duct-like openings are present within the epithelium and contain myxoid stromal tissue. Focally the epithelium extends into the connective tissue as thin anastomosing strands surround the myxoid tissue. -Diagnosis: Benign odontogenic tumor. Case#2 (2nd occurrence): -Biopsy -Diagnosis: Benign odontogenic tumor Case#2 (3rd occurrence): -Excisional biopsy -Diagnosis: AA Conclusion AA is a rare, aggressive odontogenic tumor variant with morphologic overlap with other odontogenic lesions; therefore, oral pathologists and clinicians should be familiar with this entity to achieve an accurate diagnosis and prompt management.

Adenomatoid odontogenic tumor: True neoplasm vs hamartoma

Adenomatoid odontogenic tumor (AOT) is an uncommon benign epithelial odontogenic tumor frequently involving the maxillary anterior region. It presents as an encapsulated slow growing lesion displacing the roots of associated teeth. The histopathological findings are characteristic and aid in diagnosis of this entity. We present a case of a 28 year old female who developed an expansile swelling in the anterior maxillary region which was reported as an Adenomatoid Odontogenic Tumor (AOT) post-surgical excision. This article discusses the hamartomatous vs true neoplastic nature of AOT along with histopathological findings.

Adenomatoid Odontogenic Tumor: True Neoplasm Vs Hamartoma

Adenomatoid odontogenic tumor (AOT) is an uncommon benign epithelial odontogenic tumor frequently involving the maxillary anterior region. It presents as an encapsulated slow growing lesion displacing the roots of associated teeth. The histopathological findings are characteristic and aid in diagnosis of this entity. We present a case of a 28 year old female who developed an expansile swelling in the anterior maxillary region which was reported as an Adenomatoid Odontogenic Tumor (AOT) post-surgical excision. This article discusses the hamartomatous vs true neoplastic nature of AOT.

Cytomorphological Characteristics Of Ameloblastoma By Fine Needle Aspiration Biopsy Procedure Confirmed With Histopathological Examination

Background: Ameloblastoma is the most common benign epithelial odontogenic tumor with malignant potential and is usually located in the jaw. It constitutes about 1-3% of all tumors and cysts of jaws. This entity has a very high recurrence rate of over 50% even after wide excision. Preoperative diagnosis of ameloblastoma can be made by fine-needle aspiration biopsy (FNAB) which is used as a guide for surgical planning. Case report: We report a case of a tumor in the mandible of a 41-year-old man with a preoperative diagnosis of ameloblastoma from a fine needle aspiration biopsy. Cytological examination of FNAB was confirmed by histopathological preparation of tumor tissue. Conclusion: The fine needle aspiration biopsy cytology is a reliable procedure for the pre-operative diagnosis of ameloblastoma. Pre-operative diagnosis of ameloblastoma can be used for planning therapy and early diagnosis of recurrence cases that can improve patient survival

Adenoid Ameloblastoma: A Rare Case Report And Review Of Literature

Adenoid ameloblastoma is a rare benign epithelial odontogenic tumor. Although few cases are reported in earlier literature, it is very recently added in the new 2022 WHO odontogenic lesions classification, and represents the only newly defined entity in latest classification. Here, we report a rare case of an adenoid ameloblastoma occurring in the right posterior mandible, clinically presenting as a slow growing swelling in a 50 year-old female patient.

Adenoid ameloblastoma harbors beta-catenin mutations

AbstractAdenoid ameloblastoma is a very rare benign epithelial odontogenic tumor characterized microscopically by epithelium resembling conventional ameloblastoma, with additional duct-like structures, epithelial whorls, and cribriform architecture. Dentinoid deposits, clusters of clear cells, and ghost-cell keratinization may also be present. These tumors do not harbor BRAF or KRAS mutations and their molecular basis appears distinct from conventional ameloblastoma but remains unknown. We assessed CTNNB1 (beta-catenin) exon 3 mutations in a cohort of 11 samples of adenoid ameloblastomas from 9 patients. Two of the 9 patients were female and 7 male and in 7/9 patients the tumors occurred in the maxilla. Tumors of 4 of these 9 patients harbored CTNNB1 mutations, specifically p.Ser33Cys, p.Gly34Arg, and p.Ser37Phe. Notably, for one patient 3 samples were analyzed including the primary tumour and two consecutive recurrences, and results were positive for the mutation in all three tumors. Therefore, 6/11 samples tested positive for the mutation. In the 6 mutation-positive samples, ghost cells were present in only 2/6, indicating beta-catenin mutations are not always revealed by ghost cell formation. Dentinoid matrix deposition was observed in 5/6 mutation-positive samples and clear cells in all 6 cases. None of the cases harbored either BRAF or KRAS mutations. Beta-catenin immunoexpression was assessed in the samples of 8 patients. Except for one wild-type case, all cases showed focal nuclear expression irrespective of the mutational status. Together with the absence of BRAF mutation, the detection of beta-catenin mutation in adenoid ameloblastomas supports its classification as a separate entity, and not as a subtype of ameloblastoma. The presence of this mutation may help in the diagnosis of challenging cases.

CONSERVATIVE TREATMENT OF AMELOBLASTOMA THROUGH DECOMPRESSION, WITH FOLLOW-UP FOR 5 YEARS

Ameloblastoma is a locally aggressive benign epithelial odontogenic tumor. The treatment can be radical or conservative, but the chosen technique is still controversial. We report the case of a 16-year-old patient, presenting a volumetric increase in the posterior region of the mandible, symptomatic and hardened on palpation. In imaging studies, a radiolucent, unilocular lesion was found, involving the region of the lower right first molar to the coronoid process, associated with the included third molar. An aspiration puncture was performed, showing citrus yellow liquid, followed by incisional biopsy, with extraction of teeth 47 and 48 and installation of a decompression device. The diagnosis was conventional ameloblastoma. The lesion completely regressed through decompression for a period of 1 year and the patient has been followed up for 5 years without recurrence. When conservative treatment is chosen, strict periodic clinical radiographic monitoring is essential.

Surgical Margins for Ameloblastoma in Dogs: A Review With an Emphasis on the Future.

Ameloblastoma is a benign epithelial odontogenic tumor with the capacity to aggressively invade the surrounding bone. Surgical removal of the tumor can result in extended disease-free interval (cure). However, controversy surrounds the most appropriate surgical margin required to prevent local recurrence while simultaneously minimizing morbidity. En bloc excisional surgery carries the risk of major complications such as mandibular drift, hemorrhage, and oronasal fistula formation. Conservative therapy without a safety margin reduces potential morbidity but is likely to result in local recurrence. No reliable rate, nor time to recurrence, is documented but may be as high as 91% with conservative therapy. Conversely, surgery with a 10- to 20-mm margin is associated with a 0–4.6% recurrence rate. There is no documented difference in the recurrence rate with a 10- vs. 20-mm margin. The correlation of the histologic margin with the recurrence rate following excisional surgery has not determined a required histologic safety margin. Rather, no local recurrence occurs despite narrow or incomplete margins. Thus, pathologic margins > 0 mm may be sufficient to prevent local recurrence or recurrence may be protracted. Accordingly, a narrow (5–10 mm) gross surgical margin may be the most appropriate. Additional research is required for confirmation, and only level 4 evidence on safety margins has been achieved thus far. Future work should focus on defining the extension of neoplastic cells past the demarcation of ameloblastoma on variable diagnostic imaging modalities as well as determining the recurrence rate with various surgical and histologic safety margins.

The World Health Organization Classification of Odontogenic Lesions: A Summary of the Changes of the 2022 (5th) Edition.

The 5th edition of the World Health Organization (WHO) Classification of Head and Neck Tumors opened to online access in March 2022. This edition is conceptually similar to the previous classification of odontogenic lesions. The only newly defined entity in odontogenic lesions is adenoid ameloblastoma, which is classified under benign epithelial odontogenic tumors. While not odontogenic, the surgical ciliated cyst is a new entry to the cyst classification of the jaws. In other respects, a very important change was made in the new blue books that added 'essential and desirable diagnostic criteria' for each entity to highlight the features considered indispensable for diagnosis. In this article, we review the odontogenic tumors and cysts of the jaw sections of the Odontogenic and Maxillofacial Bone Tumors Chapter, outlining changes from the 2017 WHO classification and summarizing the essential diagnostic criteria and new developments.

Recurrent tumors of ameloblastoma: Clinicopathologic features and diagnostic outcome.

Ameloblastoma is a benign epithelial odontogenic tumor with a tendency for recurrence. Some recurrent tumors could behave unpredictably with atypical microscopic changes. To study the clinicopathologic features and diagnoses of recurrent tumors of ameloblastoma. This is a 5-year (2012-2017) retrospective study of 17 consecutive patients with recurrent tumors of ameloblastoma in a Teaching Hospital in Enugu. The relevant clinicopathologic information, histology slides, and blocks were retrieved and reviewed. Descriptive analysis was used to determine the frequency, tables for categorical variables, and a Chi-square test was used to determine the statistical significance. Recurrent tumors constituted 33.3% (17/51) of all confirmed diagnoses of ameloblastoma. The histopathologic diagnosis of the recurrent tumors includes conventional ameloblastoma 58.8% (10/17), unicystic ameloblastoma 5.9% (1/17), and ameloblastic carcinoma 35.3% (6/17). There was bilateral mandibular involvement in 60.0%, pain 58.8%, ulceration 29.4%, and matted lymph nodes 5.9%. Tumors with positive fluid aspirates 82.4% (14/17) yielded dark-brown fluids in 90.0% (9/10) of recurrent ameloblastomas and in 66.7% (2/3) of ameloblastic carcinomas. There was a high recurrence rate of recurrent tumors of ameloblastoma demonstrated in the present study, with a malignant presentation in some cases.

Ameloblastoma: Pathogenesis, Clinical and Radiological Features, Classification, and Management

Background: Ameloblastoma are benign epithelial odontogenic tumors affecting the jaws. Objective: The main objective of this article is to review the pathogenesis, clinical and radiological features, classification, and management of ameloblastoma. Methods: A literature review mainly of the Pubmed database was done using the keywords: “ameloblastoma pathogenesis”; “ameloblastoma classification”; “ameloblastoma history”; “clinical and radiological features of ameloblastoma”; and “management of ameloblastoma”. Results: In 2017, ameloblastomas were classified by W.H.O into three categories: a) unicystic, b) conventional, and c) extraosseous/peripheral. Clinically, they are slow-growing, localized, aggressive neoplasms. Radologically, they mainly present as extensive, radiolucent, multilocular images, with a typical “soap bubble-like” appearance with a thinner, expanded, and eroded cortical plate. The linked non-erupted tooth is displaced and the roots of the adjacent teeth undergo clear resorption. Conclusion: Because of their late signs and symptoms, ameloblastomas are usually identified at an advanced stage. Their management typically includes a large resection with safety margins and immediate reconstruction when possible. Regular long-term postoperative follow-ups are mandatory for optimum treatment outcome and recurrence prevention.

αTAT1-induced tubulin acetylation promotes ameloblastoma migration and invasion

AbstractAmeloblastoma (AB) is the most common benign epithelial odontogenic tumor occurring in the jawbone. AB is a slowly growing tumor but sometimes shows a locally invasive and an aggressive growth pattern with a marked bone resorption. In addition, the local recurrence and distant metastasis of AB also sometimes occurs, which resembles one of the typical malignant potentials. From these points of view, to understand better the mechanisms of AB cell migration or invasion is necessary for the better clinical therapy and improvements of the patients' quality of life. Microtubules in eukaryotic cells reveal the shape of hollow cylinders made up of polymerized alpha (α)- and beta (β)-tubulin dimers and form the cytoskeleton together with microfilaments and intermediate filaments. Microtubules play important roles in cell migration by undergoing assembly and disassembly with post-translational modifications. Stability of microtubules caused by their acetylation is involved in cell migration. In this study, we investigated the expression and distribution of acetylated α-tubulin and alpha-tubulin N-acetyltransferase 1 (αTAT1), an enzyme which acetylates Lys-40 in α-tubulin, in AB specimens, and analyzed how tubulin was acetylated by αTAT1 activation in a human AB cell line, AM-1. Finally, we clarified that TGF-β-activated kinase1 (TAK1) was phosphorylated by TGF-β stimulation, then, induced tubulin acetylation via αTAT1 activation, which subsequently activated the migration and invasion of AB cells.

Frequency of Odontogenic Tumors: A Single Center Study of 1089 Cases in Japan and Literature Review

Several attempts have been made to classify odontogenic tumors; however, the need for a uniform international classification system led the World Health Organization (WHO) to present a classification of odontogenic tumors in 1971. We aimed to evaluate the number and types of odontogenic tumors examined at the Tokyo Dental College Hospital in Japan to determine the frequency and types of odontogenic tumors, based on the 2017 WHO classification system, as this information has not been reported previously in Japan. We also compared the results of our evaluation with those reported in previous studies. We conducted a clinicopathological evaluation of odontogenic tumors examined at the Tokyo Dental College Hospital between 1975 and 2020. This included an analysis of 1089 cases (malignant, n = 10, 0.9%; benign, n = 1079, 99.1%) based on the 2017 World Health Organization Classification of Head and Neck Tumors. We identified 483 (44.3%), 487 (44.7%), and 109 (10.0%) benign epithelial odontogenic, mixed odontogenic, and mesenchymal tumors, respectively. The most common tumor types were odontoma (42.5%) and ameloblastoma (41.9%). Of the 1089 cases, 585 (53.7%) and 504 (46.3%) were male and female patients, respectively. Ameloblastoma and ameloblastic fibroma occurred more commonly in male patients, whereas odontogenic fibroma and cemento-ossifying fibroma affected female patients primarily. The age at diagnosis ranged from three to 87 (mean, 29.05) years. In 319 (29.3%) patients, the age at diagnosis ranged from 10 to 19years. Ameloblastoma and odontoma were the most common tumor types among patients in their 20s and those aged 10-19years, respectively. In 737 (67.7%) and 726 (66.7%) patients, the tumors were located in the mandible and posterior region, respectively. Ameloblastoma was particularly prevalent in the posterior mandible. Odontogenic tumors are rare lesions and appear to show a definite geographic variation.

Squamous Odontogenic Tumor of Posterior Maxilla-A Report of a New Unusual Case & Literature Review

Squamous odontogenic tumor is a benign epithelial odontogenic tumor that is very unusual in the maxilla & mandible. Mostly, these are present as single lesions, but rarely they can be multifocal lesions. The nature of maxillary lesions is more aggressive. Because of their benign nature, these lesions are frequently treated with conservative surgical techniques that include curettage and surgical enucleation. We will discuss the instance of a 29-year-old lady who was misdiagnosed and treated conservatively by us. This case was examined in the light of current knowledge of the prevalence, genesis, diagnosis, and treatment of squamous odontogenic tumors, as well as a literature review.

A Long-Standing Giant Mandibular Ameloblastoma and its Management with Microvascular Free Fibular Graft: a Case Report.

Ameloblastoma is one of the most common benign epithelial odontogenic tumors of jaws. We report a case of long-standing slow-growing giant ameloblastoma involving almost all of mandibular bone. The solid multicystic lesion was excised, and the histopathological examination showed the follicular type of ameloblastoma. Furthermore, the defect was reconstructed with microvascular osteocutaneous free fibular graft.

Metastasizing Ameloblastoma: A 10 Year Clinicopathological Review with an Insight Into Pathogenesis.

Ameloblastoma, a benign but locally aggressive odontogenic tumor, often demonstrates metastasis despite benign histological features and this variant is termed as metastasizing ameloblastoma (METAM). It was classified under the malignant category in the 2005 WHO but has been re-classified under benign epithelial odontogenic tumors in the latest 2017 WHOclassification. The present review aimed at gathering the available data on METAM to update the current cognizance about the pathology. Comprehensive search of the databases (viz., PubMed, Medline, SCOPUS, Web of Science, EMBASE and Google Scholar) was done for published articles on METAM following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 42cases were extracted. The mean age of occurrence was 42.71 ± 15.87years. A slight male predilection was noted. Mandibular cases showed more metastasis than maxillary cases. Follicular ameloblastoma was most frequently encountered at secondary site followed by plexiform type. Lungs were the most commonly affected secondary sites. METAM is a rare odontogenic tumor and the diagnosis is usually made in retrospect. Inadequate treatment may result in multiple recurrences and metastasis in rare instances. Metastasis in ameloblastoma appears to be multi-factorial in nature and needs further investigation in untapped territory like exploration of quantum effects at cellular and molecular levels.

Mandibular ameloblastoma treated by hemimandibulectomy and immediate free fibula flap reconstruction - a multidisciplinary approach: case report

Ameloblastoma is a benign epithelial odontogenic tumor that presents locally invasive behavior associated with high recurrence rates. This case report aims to describe and illustrate the treatment of an extensive mandibular ameloblastoma. A 23-year-old male patient affected by ameloblastoma in the left jaw, complaining of edema in the region, dysphagia, and limitation of cervical movements. Presence of clinically visible ulcerated mass involving the teeth. Computed tomography showed an intraosseous, hypodense, expansive, multiloculated lesion. Left hemimandibulectomy was performed, followed by immediate free fibula flap reconstruction. Mandibular reconstruction with free flaps is an excellent modality to treat extensive multicystic ameloblastoma.

FOLLICULAR ADENOMATOID ODONTOGENIC TUMOR: A CASE REPORT

Adenomatoid odontogenic tumor (AOT) is a benign epithelial odontogenic tumor characterized by slow and progressive growth, accounting for 2% to 7% of all odontogenic tumors. The aim of this study is to report a case of a follicular AOT in a 20-year-old female, referred with a discreet painless increase on the left face. The intra-oral examination showed a lesion located in the left maxillary region, with 23-tooth absence and 63-tooth persistence. The radiographic exam showed the tooth 23 impacted near the left inferior orbital area, and root resorption from 24 to 27 teeth. During the surgical procedure, the lesion was easily detached, and therefore an excisional biopsy was performed. The histopathologic analysis showed benign neoplasia originating from the odontogenic epithelium formed by columnar epithelial cells arranged in tubular and ductiform structures. After the diagnostic confirmation of a TOA, the patient is under careful follow-up and has had no recurrence. Adenomatoid odontogenic tumor (AOT) is a benign epithelial odontogenic tumor characterized by slow and progressive growth, accounting for 2% to 7% of all odontogenic tumors. The aim of this study is to report a case of a follicular AOT in a 20-year-old female, referred with a discreet painless increase on the left face. The intra-oral examination showed a lesion located in the left maxillary region, with 23-tooth absence and 63-tooth persistence. The radiographic exam showed the tooth 23 impacted near the left inferior orbital area, and root resorption from 24 to 27 teeth. During the surgical procedure, the lesion was easily detached, and therefore an excisional biopsy was performed. The histopathologic analysis showed benign neoplasia originating from the odontogenic epithelium formed by columnar epithelial cells arranged in tubular and ductiform structures. After the diagnostic confirmation of a TOA, the patient is under careful follow-up and has had no recurrence.

Maxillary calcifying epithelial odontogenic tumor

Calcifying epithelial odontogenic tumor (CEOT) is a rare benign epithelial odontogenic tumor, having characteristic clinical and histopathological features. CEOT usually affects middle-aged adults without any gender predilection. Most of these cases are intraosseous and appear predominantly in the mandibular posterior region. It is not commonly found in the maxillary region; however, if appear, it can easily involve the surrounding areas including the maxillary sinus. Here, we discuss a case of CEOT in the maxillary premolar–molar region, the common site being the posterior mandible.

A 73-year-old man with pindborg tumor: A case report

Calcifying epithelial odontogenic tumor (CEOT) is an uncommon, benign epithelial odontogenic tumor, first described in 1955 by Pindborg, with a locally aggressive behavior; it represents only 1% of the total odontogenic tumors. The origin of this locally invasive tumor remains unknown. It is thought to arise from stratum intermedium. It commonly affects the posterior mandible manifesting as a slow-growing asymptomatic swelling, often associated with an impacted tooth. The tumor usually occurs between the second and sixth decade of life and has no gender predilection. In this article we report a case of 73-year-old man with Pindborg tumor localized in lower right gum.