Adenomatoid Odontogenic Tumor (AOT) Arising from a Dentigerous Cyst: Literature Review and Report of a Case

Clear cell adenomatoid odontogenic tumour and dentigerous cyst: an uncommon hybrid combination - case and review

Odontogenic tumours and cysts have a characteristic presentation, histopathologically and clinically. The diagnostic criteria and nomenclature are distinct as elaborated in 2017 WHO classification. But one can occasionally and infrequently find an association between different odontogenic tumours and cysts, like calcifying epithelial odontogenic tumour (CEOT) and adenomatoid odontogenic tumour (AOT), CEOT and ghost cell tumour. Some of the odontogenic tumours and cysts share the site of occurrence, intraosseous location, teeth involved/quadrant involved and histopathology too. Hence these lesions are considered for differential diagnoses in most cases. But some instances report hybrid or associated tumours and cyst cases. Here we present a case of dentigerous cyst in association with AOT that showed variation in cell type, pattern and induction pattern.

Multiple adenomatoid odontogenic tumours associated with eight impacted teeth

Adenomatoid odontogenic tumour (AOT) is a benign tumour that arises from odontogenic epithelial remnants. AOTs usually present as innocuous lesions with limited growth potential. Multiple AOTs are frequently reported in the literature, with reports of tumours associated with up to seven impacted teeth. Multiple AOTs have also been described in association with Schimmelpenning syndrome. This case report highlights the rare occurrence of multiple AOTs involving eight impacted teeth in a 9-year-old male patient. Radiographic examination showed features of enamel hypoplasia and multiple prominent dilated gubernaculum dentis associated with some of the impacted teeth. The patient also presented with a linear epidermal nevus involving the left face and intraoral mucosal papillomatous growths, clinical features highly compatible with Schimmelpenning syndrome.

Periodontitis and oral cancer - current concepts of the etiopathogenesis

Gingival tissues are attacked by oral pathogens which can induce inflammatory reactions. The immune-inflammatory responses play essential roles in the patient susceptibility to periodontal diseases. There is a wealth of evidence indicating a link between chronic inflammation and risk of malignant transformation of the affected oral epithelium. Periodontitis is associated with an increased risk of developing chronic systemic conditions including autoimmune diseases and different types of cancers. Besides, some risk factors such as smoking, alcohol consumption and human papilloma virus have been found to be associated with both periodontitis and oral cancer. This review article aimed to study the current concepts in pathogenesis of chronic periodontitis and oral cancer by reviewing the related articles.

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.

[A CASE OF ADRENAL ADENOMATOID TUMOR DIAGNOSED BY IMMUNOHISTOCHEMICAL EVALUATION]

An adenomatoid tumor is a benign tumor of mesothelial derivation, typically found in the genital track. However, though extremely rare, an adenomatoid tumor can be found in the adrenal gland, making it difficult to clinically and radiologically differentiate it from an adrenocortical tumor or a pheochromocytoma prior to surgery. We encountered a-52-year old man with an adenomatoid tumor in the adrenal gland, who presented with an incidentally discovered left adrenal mass revealed by PET-CT from his regular health examinations. He had been diagnosed with paroxysmal hypertension two years before and was being treated with a hypolipidemic agent. Abdominal computed tomography revealed a left adrenal mass measuring 25 × 15 mm, and the findings were different from the typical adrenocortical adenoma or pheochromocytoma. Although laboratory examinations of his blood samples indicated normal adrenal function, 24-hour urine specimens revealed high levels of 17-OHCS, 17-KS, and catecholamine. Both ¹³¹I-MIBG scintigraphy and phentolamine tests showed negative findings. The patient underwent a laparoscopic left adrenalectomy. The cut surface of the left adrenal gland weighing 21 g contained a white, solid mass measuring 25 × 15 × 20 mm within the adrenocortical tissue. Histologically, the tumor was composed of small tubules lined by eosinophilic tumor cells. The tumor cells were immunohistochemically positive for cytokeratins and calretinin, but negative for steroidogenic factor-1. Therefore, based on these findings, we diagnosed this tumor as an adrenal adenomatoid tumor. Histopathologically, the adrenal adenomatoid tumor may be difficult to distinguish from an adrenocortical adenoma, carcinoma, lymphangioma, hemangioma, angiosarcoma, or metastatic adenocarcinoma. Under these conditions, immunohistochemical examination is useful for definite diagnosis.

Multiple Pathology in a Single Lesion: AOT Associated with Dentigerous Cyst

Odontogenic cysts and tumors are quite common occurrences in jaw bones, although both of them occurring together are rare. The epithelial lining of odontogenic cyst has a potential to transform into neoplastic conditions like squamous cell carcinoma and mucoepidermoid carcinoma, and odontogenic tumors like ameloblastoma and adenomatoid odontogenic tumor. However, the frequency of such cases being encountered is very less. Here, we report a case of adenomatoid odontogenic tumor (AOT) associated with a dentigerous cyst around the crown of an unerupted lateral incisor (follicular variant), in a 14-year-old boy. We also attempt to unravel its mechanism of cytodifferentiation and tumor progression. The origin and nature of such kind of lesions (i.e., independent development of multiple pathologies as a single lesion in a single location, single pathology giving rise to another pathology or a distinct entity/new variant) cannot be explained with certainty at this point of time. The molecular mechanism of tumor development needs to be further elucidated in order to conclude that a different entity called 'hybrid' AOT exists.