Adenomatoid odontogenic tumor (AOT) originating in a unicystic ameloblastoma: a case report

Hybrid odontogenic lesions: A case series of a rare entity

Background

The occurrence of hybrid odontogenic lesions with two or more morphologically distinct components is a rare phenomenon and poses a diagnostic challenge. We aimed to study the clinical, radiological, and pathological features and behavior of hybrid odontogenic lesions, to enhance awareness about these rare lesions.

Method

Hematoxylin and Eosin slides of hybrid odontogenic lesions diagnosed between January 01, 2012 and December 31, 2020, were reviewed. Demographic and radiological information were obtained from the patient's medical records.

Results

8 cases were diagnosed with a mean age of 19.1 years and male to female ratio of 1:1.7. Involvement of mandible was more common (n = 5) as compared to maxilla (n = 3). All patients presented with swelling for an average of 9.75 months (3-25 months) duration. Bleeding, loose teeth, pain and facial asymmetry were reported in 5,3, 3, and 2 cases, respectively. Radiologically, 7 cases were well demarcated, 75% cases (n = 6) were radiolucent, and average radiological size was 4.8 cm. All patients were managed with surgery alone. 5 cases (62.5%) underwent enucleation and curettage, while local excision, en-block resection and segmental mandibulectomy were performed in 1 case each. Histologically, ossifying fibroma/cemento-ossifyiong fibroma were the most lesion, occurring in 5 cases (62%), followed by giant cell granuloma like lesions (GCG) i.e., central and peripheral giant cell granuloma (n = 3), Adenomatoid Odontogenic tumor (AOT) (n = 2), and DC (n = 2), ameloblastic fibroma (AF) (n = 1), Ameloblastoma (n = 1), calcifying odontogenic cyst (COC) (n = 1), and complex odontoma (n = 1). No evidence of recurrence was noted after 4-99 months of surgery (mean: 32.9) in cases with available data (n = 7). Long-term complaints included facial asymmetry (n = 2) and pain (n = 1).

Conclusion

Most hybrid odontogenic lesions affect young females in the second decade of life and commonly show COF and OF as hybrid components. A conservative approach to management appears adequate.

Adenomatoid Odontogenic Tumor Associated with Impacted Mandibular Canine - A Case Report

Adenomatoid odontogenic tumor (AOT) is a relatively rare, benign, hamartomatous, and cystic odontogenic neoplasm that was first described more than a century ago. It accounts for 2-7% of all odontogenic tumors. The lesion still continues to intrigue experts with its varied histomorphology and controversies regarding its development. The present article describes a case of cystic AOT with an unusual histomorphology associated with an impacted 43 in a 15-year-old male.

Adenomatoid odontogenic tumor: Case series of 14 with wide range of clinical presentation

Background

To present 14 cases of adenomatoid odontogenic tumor (AOT), highlighting their clinical, radiographic, and histologic characteristics.

Material and Methods

Fourteen cases of AOT were retrieved from the archives of the Oral Pathology Biopsy Service (OPBS). Clinical, radiologic, and histologic findings are described.

Results

Fourteen AOT cases were reviewed, of which 12 were intraosseous and two were peripheral (gingiva). The cases came from eight females and six males with an age range of 11–30. Of the 12 intraosseous cases, nine were follicular (associated with impacted teeth), while three were extra-follicular (present between teeth). Six of the 12 cases were in the maxilla, and the other six were in the mandible. The two peripheral cases presented as nodules on the buccal gingiva of the anterior maxillary teeth. Radiographically, all 12 follicular and extra-follicular cases were unilocular radiolucencies; of those, only one had specks of radiopacity. Histologically, all specimens were similar in morphology, demonstrating a varied degree of duct-like structures, epithelial spheres, spindle-shaped epithelial cells, calcifications, and a thick capsule. The two peripheral cases had no capsule.

Conclusions

AOT usually affects patients under 20 years of age, with a female to male ratio close to 2:1. Presentation in the anterior maxilla is almost twice as common as in the anterior mandible. Radiographically, AOT presents as a unilocular radiolucency more commonly associated with impacted teeth, simulating a dentigerous cyst. We present 14 new cases of AOT (nine follicular, three extra-follicular, and two peripheral) with discussions of their clinical, radiographic, and histological features.

Key words:Adenomatoid, odontogenic, tumor.

Follicular Adenomatoid Odontogenic Tumor in Mandible: A Rare Case Report

Adenomatoid odontogenic tumor (AOT) is a relatively rare, benign, hamartomatous, and cystic odontogenic neoplasm that was first described more than a century ago. The lesion still continues to intrigue experts with its varied histomorphology and controversies regarding its development. The present article describes a case of cystic AOT with an unusual histomorphology associated with an impacted 44 in a 21-year-old male.

A case report and short review on changing trends in the site of occurrence of adenomatoid odontogenic tumor: Unravelling the past 15 years

Adenomatoid odontogenic tumor (AOT) is an uncommon benign odontogenic lesion, with debatable histogenesis and variable histopathology. A systematic and diverse insight into the evolution, clinical presentation, histology, and immunohistochemical findings of this lesion is reviewed and presented. We reviewed the data published from 2000 to 2014 of approximately 255 cases that revealed a significant change in the incidence of predominant site involved, in contrast to the findings published by Reichart. We have also included the chronological order of events leading to the coining of the term AOT, which shows the curiosity that has been dedicated to understanding the lesion. Immunohistochemistry is considered to be a hallmark in pathology for learning the molecular pathogenesis and giving a correct final diagnosis. Several markers have been used to investigate and understand this lesion, and a compilation of the findings has been tabulated.

Dentigerous Cyst Associated with Adenomatoid Odontogenic Tumour

Adenomatoid odontogenic tumour (AOT), a tumour composed of odontogenic epithelium, is an uncommon tumour of odontogenic origin that accounts for only 2.2- 7.1% of all odontogenic tumours. Very few cases of AOT associated with Dentigerous cyst (DC) have been reported till date, most cases are in females and have a striking tendency to occur in the anterior maxilla. The present case is that of a 14-year-old female who revealed a large radiolucent lesion associated with the crown of an unerupted canine located in the left maxillary anterior region. The microscopic examination revealed the presence of AOT in the fibrous capsule of a DC. In this paper, we describe the importance of grossing, sectioning and complete examination of the slide to diagnose such hybrid lesions.

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.

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

Adenomatoid odontogenic tumor (AOT) is an uncommon benign tumor of odontogenic origin composed of odontogenic epithelium in a variety of histopathological patterns. These lesions are usually solid but are occasionally cystic. AOT has been reported to occur in association with odontogenic cysts. Very few cases have been described that arise in association with a dentigerous cyst. A systematic search of the English-language medical literature in PubMed and Medline search (keywords adenomatoid odontogenic tumor, dentigerous cyst) data bases revealed only ten such cases. The present case is very unique, exceptional and first of this kind that occurred in the posterior mandible associated with an impacted lower first premolar in a 19-year old female patient. The intraosseous follicular AOT, as this case reported here, frequently resemble dentigerous cysts. There is an uncertainty whether the lining of an associated cyst represents a true dentigerous cyst, cystic change within an AOT or may represent a distinct entity. We believe that this case represents an odontogenic cyst with neoplastic change. Hence, in such cases, the final diagnosis should be made on the basis of histological examination of extensive tissue sampling of entire excised tissue specimen. Further studies to determine whether the AOT derived from an odontogenic cyst could represent a distinct variant are to be done.

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.

Dentigerous cyst or adenomatoid odontogenic tumor: clinical radiological and histopathological dilemma

Adenomatoid odontogenic tumor (AOT) is a well-recognised slow growing benign tumor derived from complex system of dental lamina or its remnants. This lesion is categorised into three variants of which the more common variant is follicular type which is often mistaken for dentigerous cyst. We present a case of AOT in a 14-year-old male who was misdiagnosed as dentigerous cyst. Clinical radiological and therapeutic characteristics of the case are commented on in detail.

Mural adenomatoid odontogenic tumour as anterior mandibular swelling: a diagnostic challenge

Adenomatoid odontogenic tumour is an uncommon, benign, hamartomatous lesion that commonly affects the anterior maxilla and has two radiographic variants, follicular and extrafollicular where the former is more common than the latter. Here, we report a case of 15-year-old female with midline swelling of the mandible. Radiographically, impacted right permanent mandibular canine was associated with the radiolucent lesion. Dentigerous cyst was given as provisional diagnosis. However, histologically the lesion represented the features of cystic variant of Adenomatoid odontogenic tumour.

A rare case of extrafollicular adenomatoid odontogenic tumour in the posterior region of the mandible: misdiagnosed as residual cyst

Adenomatoid odontogenic tumor is a relatively uncommon distinct odontogenic neoplasm. It is an uncommon tumor of odontogenic origin with varying number of ductlike structures and inductive changes in the stroma. It is a benign and slow growing epithelial tumor and represents 3% of all odontogenic tumors. Its occurrence is more common in anterior region of the maxilla than mandible. Most of the adenomatoid odontogenic tumors occur intra-osseously but few peripheral variant have been reported which are attached to the gingival structures. The intra-osseous Adenomatoid odontogenic tumor may be related to unerrupted tooth (follicular varient) or may not (extrafollicular varient) be related to unerrupted tooth. This paper is to present a rare case of an extrafollicular Adenomatoid odontogenic tumor occurring in the body of the mandible in a male patient which is distinct and secondly it was clinically and radiographically diagnosed as residual cyst. The diagnosis of Adenomatoid odontogenic tumor was confirmed by Histopathological investigation. How to cite this article: Shivali V, Khanna VD, Khanna P, Singh A, Pandey A, Ahuja T. A Rare Case of Extrafollicular Adenomatoid Odontogenic Tumour in the Posterior Region of the Mandible: Misdiagnosed as Residual Cyst. J Int Oral Health 2013; 5(5):124-8.

Current concepts and occurrence of epithelial odontogenic tumors: I. Ameloblastoma and adenomatoid odontogenic tumor

Ameloblastomas and adenomatoid odontogenic tumors (AOTs) are common epithelial tumors of odontogenic origin. Ameloblastomas are clinico-pathologically classified into solid/multicystic, unicystic, desmoplastic, and peripheral types, and also divided into follicular, plexiform, acanthomatous, granular types, etc., based on their histological features. Craniopharyngiomas, derived from the remnants of Rathke's pouch or a misplaced enamel organ, are also comparable to the odontogenic tumors. The malignant transformation of ameloblastomas results in the formation of ameloblastic carcinomas and malignant ameloblastomas depending on cytological dysplasia and metastasis, respectively. AOTs are classified into follicular, extrafollicular, and peripheral types. Ameloblastomas are common, have an aggressive behavior and recurrent course, and are rarely metastatic, while AOTs are hamartomatous benign lesions derived from the complex system of the dental lamina or its remnants. With advances in the elucidation of molecular signaling mechanisms in cells, the cytodifferentiation of epithelial tumor cells in ameloblastomas and AOTs can be identified using different biomarkers. Therefore, it is suggested that comprehensive pathological observation including molecular genetic information can provide a more reliable differential diagnosis for the propagation and prognosis of ameloblastomas and AOTs. This study aimed to review the current concepts of ameloblastomas and AOTs and to discuss their clinico-pathological features relevant to tumorigenesis and prognosis.

Critical evaluation of the radiological and clinical features of adenomatoid odontogenic tumour

OBJECTIVES

The aim of this study was to evaluate the radiological and clinical features of adenomatoid odontogenic tumours (AOTs).

METHODS

A total of 272 cases (267 from the English-language literature and 5 new cases) were analysed with special emphasis on their radiological features.

RESULTS

The patients' ages at time of diagnosis ranged from 3 years to 82 years (mean 18.4 years). The maxilla-to-mandible ratio was 1.7:1. Mandibular lesions were significantly more frequent among patients older than 16 years (p = 0.032). Expansion of the cortex was significantly more prominent among patients older than 16 years (p = 0.045). There was a positive correlation between the size of the lesion and the age of the patient at the time of diagnosis (p = 0.016). The size was also associated with increased root resorption (p < 0.001), ill-defined borders (p < 0.001), expansion (p < 0.001) and perforation of the cortex (p < 0.001). Small opacities were present in 77% of lesions and were associated with expansion of the cortex (p = 0.043). The significant radiological features in patients aged 30 years and above were root resorption (p = 0.013) and lesions crossing the midline (p = 0.019).

CONCLUSIONS

The size of an AOT is influenced by the patient's age. It is also associated with root resorption, ill-defined borders, expansion and perforation of the cortex, but it cannot be ruled out that those changes reflect a longer duration of the lesion.

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

Adenomatoid odontogenic tumor (AOT) is an uncommon benign tumor of odontogenic origin composed of odontogenic epithelium in a variety of histopathological patterns. These lesions are usually solid but are occasionally cystic. AOT has been reported to occur in association with odontogenic cysts. Very few cases have been described that arise in association with a dentigerous cyst. A systematic search of the English-language medical literature in PubMed and Medline search (keywords adenomatoid odontogenic tumor, dentigerous cyst) data bases revealed only ten such cases. The present case is very unique, exceptional and first of this kind that occurred in the posterior mandible associated with an impacted lower first premolar in a 19-year old female patient. The intraosseous follicular AOT, as this case reported here, frequently resemble dentigerous cysts. There is an uncertainty whether the lining of an associated cyst represents a true dentigerous cyst, cystic change within an AOT or may represent a distinct entity. We believe that this case represents an odontogenic cyst with neoplastic change. Hence, in such cases, the final diagnosis should be made on the basis of histological examination of extensive tissue sampling of entire excised tissue specimen. Further studies to determine whether the AOT derived from an odontogenic cyst could represent a distinct variant are to be done.

Bilateral adenomatoid odontogenic tumour of the maxilla in a 2-year-old female--the report of a rare case and review of the literature

Multifocal odontogenic lesions are uncommon and have only been observed in conditions associated with known genetic mutations. To the best of our knowledge, only two cases of multifocal adenomatoid odontogenic tumours (AOT) have previously been reported in the literature. In this study, we report the first case of a bilateral, separate AOT in the maxilla in the midline in a 2-year-old female. The patient presented with bilateral expansile masses in the maxilla on either side of the midline which had been present for 6 months. She was asymptomatic and had occasional difficulty in breathing. The tumour was diagnosed as AOT and was surgically enucleated along with the associated teeth. The patient recovered well and has been on recall for 5 years. The follow-up panoramic radiograph made a fortnight ago revealed evidence of three new radio-opaque lesions with an associated tooth in the region of the anterior mandible, the premolar region of the right maxilla and the molar region of the left maxilla. To acquire additional information about AOT, all reports regarding AOT cited in 'PubMed' from 1995 onward were reviewed and the incidence, clinical features, radiographic features and management of AOT are discussed in this study.

Adenomatoid odontogenic tumor - a report of two cases with histopathology correlation

Adenomatoid odontogenic tumor (AOT) is an uncommon, hamartomatous, benign, epithelial lesion of odontogenic origin that was first described by Driebaldt in 1907, as a pseudo-adenoameloblastoma. The current World Health Organisation (WHO) classification of odontogenic tumors defines AOT as being composed of the odontogenic epithelium in a variety of histoarchitectural patterns, embedded in mature connective tissue stroma, and characterized by slow, but progressive growth. The current article reports two cases with different presentations; first in a young female patient and the second in a middle-aged male patient. The importance of biopsy, which is the gold standard for diagnosis, and its use in planning of the treatment is discussed.

Adenomatoid odontogenic tumor associated with dentigerous cyst of the maxillary antrum: A rare entity

Adenomatoid odontogenic tumor (AOT) is an uncommon tumor of odontogenic origin composed of odontogenic epithelium in a variety of histoarchitectural patterns. Most cases are in females and have a striking tendency to occur in the anterior maxilla. However, AOT of the maxillary antrum is extremely rare. A 25-year-old female presented with a large radiolucent lesion associated with the crown of an unerupted canine located in the maxillary antrum, which was clinically diagnosed as dentigerous cyst. The microscopic examination revealed the presence of AOT in the fibrous capsule of a dentigerous cyst. Very few cases of AOT associated with dentigerous cyst have been reported till date. A case of gigantic AOT that occupied the maxillary sinus and associated with dentigerous cyst is described. Also, an attempt has been made to determine whether the AOT derived from the dentigerous cyst could represent a distinct hybrid variety.

Adenomatoid odontogenic tumour: tumour or a cyst, a histopathological support for the controversy

Adenomatoid odontogenic tumour (AOT) is a well-established odontogenic tumour with various clinicopathological variants. AOT quite frequently mimics an odontogenic cyst commonly a dentigerous cyst. Histologically a cystic component of AOT has been described in the literature. In the present paper we review the literature for the AOTs arising in an odontogenic cyst and add to the literature a case of cystic AOT. The present review is aimed to provide an insight to the varied demographic profile, clinical behavior and prognosis of cystic variant of AOT.