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.     

Analysis of 55 cases of adenomatoid odontogenic tumor in an Indian population and review of literature

Background This study reviews the demographic, clinical and radiographic features of adenomatoid odontogenic tumor(AOT) diagnosed in an Indian population over 50 years and also evaluate and compare follicular AOT(F-AOT) and extra-follicular AOT(EF-AOT).Material and Methods 55 diagnosed cases of AOT from 1971-2020 were studied retrospectively. The data regarding the age, sex, location, variant of AOT, duration, clinical features, radiographic appearance, treatment and recurrence were collected and analysed.Results Of the 722 odontogenic tumors diagnosed, 7.6% were AOTs with higher prevalence of extra-follicular (67.3%) than follicular (32.7%) variant. All the tumors were intraosseous with a marked predilection for maxilla over mandible, ratio 2:1. The patients mean age was 19.8 years with slightly higher female predilection (male:female ratio - 1:1.5). The anterior region (76.4%) was more frequently affected and entire quadrant was involved in 21.8% cases. Clinically, asymptomatic, slow-growing swelling was seen in 81.8% cases with duration of 15 days to 10 years. Radiographically, AOT appeared as well-corticated radiolucent lesion. Canine was the most commonly impacted tooth. Recurrence was seen in 3 cases.Conclusions Interestingly, in this series extra-follicular was twice more common than follicular AOT. Few cases involved the entire quadrant or crossed the midline of either jaws. Key words:Adenomatoid odontogenic tumor (AOT), follicular AOT, extrafollicular AOT, Indian population, odontogenic tumor.     

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 tumour: An enigma

Adenomatoid odontogenic tumour (AOT) is an uncommon, hamartomatous, benign epitheial lesion of odontogenic origin. 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 aim of this paper is to present three rare cases of intraosseous AOTs with varied clinical and radiographic features imposing the fact that AOT should be included in differential diagnosis of routine odontogenic cysts and tumours.     

Ghost cell odontogenic carcinoma arising in the background of a calcifying odontogenic cyst

Ghost cell odontogenic carcinoma (GCOC) is a rare malignant neoplasm, representing 3% of all ghost cell lesions of the jaws. They can arise de novo or from a pre-existing calcifying odontogenic cyst (COC) or dentinogenic ghost cell tumour (DGCT). A systematic review of the literature reported only 12 cases of a GCOC arising from a pre-existing COC. This report highlights an additional case of a GCOC arising from a pre-existing COC after 3 years in an adolescent male. The patient initially presented with a painless swelling of the right mandibular corpus. Panoramic radiographic examination showed an expansive unilocular radiolucent lesion. After 3 years, the radiographic features appeared more aggressive with increased expansion and cortical perforation. A wide surgical resection was performed, whereby the lesion was diagnosed as a GCOC. Due to the rarity of these malignant neoplasms, limited information is available regarding their biological behaviour. One-year follow-up revealed no clinical signs of recurrence.

     

The odontogenic keratocyst: A benign cystic tumor?

Three hundred nineteen odontogenic keratocysts from 255 patients (167 males and 88 females, a 2:1 ratio) were histologically and clinically examined. The cysts sometimes occurred as multiple or recurrent lesions or in association with Gorlin's syndrome. The rate of recurrence for the total population was 27%. The 116 patients who were tentatively diagnosed as having keratocyst prior to surgery had a recurrence rate of 26%. There was no direct correlation between a large number of different histopathologic parameters and the propensity of a lesion to recur. Based on these data, a theory for the growth mechanism of these lesions is presented, and it is that the odontogenic keratocyst should be regarded as a benign cystic neoplasm and treated accordingly.     

An analysis of oral and maxillofacial pathology found in children over a 30-year period

AIM: The vast majority of oral diseases are confined to oral tissues, but numerous underlying systemic conditions may present with signs and symptoms within the oral cavity. Since the epidemiology of diseases is variable between regions, the authors carried out Europe's first paediatric-based survey of oral and maxillofacial pathology specimens submitted for diagnosis. DESIGN: All entries for specimens from children between the ages of 0 and 16 years during the 30-year period from 1973 to 2002 were retrieved and compiled into 12 diagnostic categories. RESULTS: During the study period, 4406 (8.2%) specimens came from children between the ages of 0 and 16 years, with a male to female ratio of 1.01. The diagnostic category with the largest number of specimens was tooth pathology (22.1%), followed by salivary gland disease (19.1%) and mucosal pathology (12.1%). In all, there were 114 benign tumours of nonodontogenic origin, 43 odontogenic tumours and 31 malignant tumours. The most frequently diagnosed lesions were mucous extravasation cysts, which accounted for over 16% of cases. Periapical pathology in the form of a radicular cyst, residual cyst or chronic periapical granuloma formed almost 13% of all cases. CONCLUSIONS: This survey shows that, while nearly 10% of specimens submitted to the authors' laboratory are from children under 16 years of age, the majority of lesions are of a benign nature, requiring minimal intervention; less than 1% of cases comprise malignant lesions. Odontogenic tumours are relatively rare in this age group; however, certain lesions such as adenomatoid odontogenic tumour and ameloblastic fibroma occur predominantly in children and, therefore, remain an important diagnostic consideration.     

Argyrophilic nucleolar organizer regions (AgNORs) in ameloblastomas and adenomatoid odontogenic tumours (AOTs)

Twenty-two cases of ameloblastoma and ten cases of adenomatoid odontogenic tumour (AOT) were analyzed comparatively by the AgNOR technique. Ameloblastomas were distributed into three groups according to their clinical behaviour: primary lesions without recurrences (PLWTR), 5 cases; primary lesions with recurrences (PLWR), 4 cases; and recurrences, 13 cases. The cases were also regrouped according to their histological pattern: follicular (9 cases), plexiform (7 cases), acanthomatous (4 cases) and unicystic (2 cases). Considering histological patterns, there was a significant statistical difference only between follicular and plexiform types. There were no significant differences between the group of ameloblastomas and the group of AOTs or between the three groups of ameloblastomas with different clinical behaviour. Our results strongly suggest that the distinct clinical behaviour of ameloblastomas and AOT is not correlated with their cellular proliferation ratio. Thus, the infiltrative ability of the ameloblastomas is probably not related to the cellular proliferation index of these tumours.     

Odontogenic lesions in opercula of permanent molars delayed in eruption

Opercula of permanent first and second molars delayed in eruption were investigated histologically to detect possible causes of eruption failure. The material comprised operation specimens from exposure of 74 non-erupted molars in 63 young individuals (34 boys, 29 girls). Eighteen of the 74 specimens (or 24.3%) were diagnosed as "classical" odontogenic tumors belonging to the following entities: ameloblastic fibroma (seven), ameloblastic fibrodentinoma (six), ameloblastic fibro-odontoma (four) and complex odontoma (one). Twenty-two specimens (or 29.7%) showed a hitherto unrecognized odontogenic lesion of hamartomatous character, termed odontogenic giant cell fibromatosis (OGCF). Thus, 54.1% of the specimens could be diagnosed as odontogenic tumors or hamartomas. Histomorphologic changes could not be detected in the remaining 34 specimens (45.9%). Odontogenic tumors were associated with unerupted first molars much more frequently than with second molars (ratio 8:1). The OGCF had a strong association with unerupted mandibular molars. Further, opercula of mandibular first molars frequently revealed odontogenic lesions whereas tissue overlying the crown of unerupted maxillary second molars often was reported as normal operculum.     

Odontogenic tumours: a retrospective study of 1642 cases in a Chinese population

A total of 1642 odontogenic tumour cases retrieved from the files of the College of Stomatology, Sichuan University, China were retrospectively analyzed for gender, age, tumour site and relative frequency of various types, and the data compared with that of previous reports. The final diagnosis in each case was based on the WHO 2005 histopathological classification of odontogenic tumours. Of these tumours 1592 (97.0%) were benign and 50 (3.0%) were malignant. Ameloblastoma (40.3%) was the most frequent type, followed by keratocystic odontogenic tumour (35.8%), odontoma (4.7%) and odontogenic myxoma (4.6%). The mean age of the patients was 32.1, with a wide range (3-84 years). The male-female ratio and maxilla-mandible ratio were 1.4:1 and 1:4.0, respectively. Ameloblastoma and keratocystic odontogenic tumours, important indications of extensive surgical procedures, are not considered rare in this Chinese population, whereas odontoma is uncommon.     

Adenomatoid odontogenic tumour (adenoameloblastoma).

Two cases of adenomatoid odontogenic tumour affecting the jaws of two young Nigerian Africans are described. One was diagnosed clinically as a cyst, the other as an ossifying fibroma, but their true nature was later unmasked by histopathological studies. Although considered rare, the adenomatoid odontogenic tumour should be borne in mind in the differential diagnosis of radiolucent lesions of the jaws since an incorrect diagnosis may lead to mutilating surgery whereas the lesion is amenable to a conservative surgical approach. It is also important to examine histologically all excised specimens from the jaws even in the so-called 'obvious cases.     

Odontogenic tumours in children and adolescents: a study of 78 Nigerian cases.

BACKGROUND: There is paucity of literature on odontogenic tumours in children and adolescents. Available records are difficult to compare due to differences in study criteria. To contribute to the records, a 20-year study of odontogenic tumours on the basis of the WHO classification (Kramer et al., 1992) in Nigerian African children and adolescents < or =18 years of age was undertaken. MATERIAL: A retrospective survey of oral/jaw tumours and allied lesions in children and adolescents < or =18 years of age seen at the Maxillofacial Unit, Ahmadu Bello University Teaching Hospital, Kaduna, Nigeria between 1979 and 1998. Data collected were histopathologic type, age, clinical features, radiologic appearance, treatment and record of recurrence. METHOD: Odontogenic tumours selected using the WHO classification were used for further study. Data were collected from case notes, radiographs, histopathologic reports and follow-up records. Information retrieved was used to complete a questionnaire and subjected to analysis. RESULTS: Two hundred and fifty-two (252) subjects < or =18 years were recorded, from which 78 (31%) had odontogenic tumours. Among seven types of odontogenic tumours seen, ameloblastoma (54%), odontogenic myxoma (19%) and adenomatoid odontogenic tumour (9%) were predominant. All patients seen were from 6 to 18 years with more than half (53%) between 15 and 18 years of age. A patient with multiple, bilateral odontomas of the maxilla and mandible resembling Herrmann's syndrome was recorded. Seventy-three patients were treated using enucleation (37%), dentoalveolar resection with preservation of lower border (15%) and segmental resection (48%). Five patients absconded after tumour diagnosis. No tumour recurrence was recorded in 65 treated cases followed-up for between 2 months and 10 years. CONCLUSION: This report shows that while ameloblastoma was the predominant odontogenic tumour, its frequency in Nigerian African children was lower than in the adult population. A case resembling Herrmann's syndrome is also presented.     

Immunohistochemical detection of p53 and PCNA in ameloblastoma and adenomatoid odontogenic tumor

Although ameloblastoma and adenomatoid odontogenic tumor (AOT) belong to the same group according to the World Health Organization, they show different biologic behaviors. PCNA, an amplifier of cell proliferation, and p53, a tumor suppressor protein, are overexpressed in some odontogenic lesions. The purpose of this study was to immunohistochemically evaluate the expression of p53 and PCNA to clarify the possible role of these proteins in different behaviors of ameloblastoma and AOT. The immunohistochemical expression of PCNA and p53 was determined in 30 solid ameloblastomas and 12 AOTs. Statistical tests including one-way ANOVA, t-test, chi-square, Mann-Whitney U and Kendall were used to analyze the data. All tissue sections (except one specimen of plexiform ameloblastoma) exhibited immunoexpression for p53. PCNA was expressed in all specimens. There was no significant difference in PCNA expression between ameloblastomas and AOTs (P > 0.05). For p53, there was no statistical difference between subtypes of ameloblastomas (P > 0.05), whereas statistical differences were observed between ameloblastomas and AOTs (P < 0.001). There was no statistical difference in PCNA intensity of staining between ameloblastomas and AOTs (P > 0.05), whereas the p53 intensity in ameloblastomas was stronger than AOTs (P < 0.05). Positive correlation between PCNA and p53 was observed. We concluded that PCNA overexpression is not responsible for the difference in clinical behavior of these two lesions, whereas the expression of p53 in ameloblastoma may explain the more aggressive nature of this tumor compared with AOT.     

An observational retrospective study of odontogenic cyst´s and tumours over an 18-year period in a Portuguese population according to the new WHO Head and Neck Tumour classification

Background Odontogenic cysts and tumours of the jaws represent one of the most prevalent groups of oral-maxillofacial lesions. We aimed to evaluate the clinical and pathological characteristics of a cohort of odontogenic cysts (OC) and odontogenic tumours (OT) of the jaws in a Portuguese population. Material and Methods This observational retrospective study analysed patients diagnosed with either an OC or OT of the jaws at a central hospital of Oporto, Portugal, between 1988 and 2006. Data collected from patients’ files included demographic, clinical, radiological and histopathological information. Recurrence was evaluated using univariate and multivariate analysis. Results The sample consisted of 397 patients, 231 males (58.2%) and 166 females (41.8%), with a mean-age of 36.7±17 years. Twenty-seven patients (6.8%) presented with more than one lesion providing a total of 433 lesions. There were 396 (91.5%) OC, mostly represented by radicular cysts (n=257;59.4%), dentigerous cysts (n=79;18.2%), or odontogenic keratocysts (n=50;11.5%). There were 37 (8.5%) OT, mostly represented by ameloblastomas (n=16;3.7%), and odontomas (n=9;2.1%). The most common initial clinical manifestation was swelling (n=224;51.7%). Recurrence was observed in 30 cases (6.9%), mostly in ameloblastomas (n=6;37.5%) and odontogenic keratocysts (n=12;24%). In the multivariate analysis the diagnosis classification of the lesion was the only independent and significant variable related with the recurrence (P=0.04). Conclusions Radicular cysts were the most commonly occurring type of OC and ameloblastomas the most commonly occurring OT. Amelobastomas and odontogenic keratocysts were the lesions with the highest rates of recurrence. This large sample provides useful information about the frequency profile and characteristics of OC and OT over a period of 18 years, allowing valuable comparison with data from other countries. Key words:Odontogenic cysts and tumours, radicular cyst, dentigerous cyst, odontogenic keratocyst, ameloblastoma, recurrence.     

Differential expression of Cyclin D1 in keratin-producing odontogenic cysts

Objetives: The aim of the present study was to analyze the expression levels of Cyclin D1 (CCD1), a nuclear protein that plays a crucial role in cell cycle progression, in a series of keratin-producing odontogenic cysts. Study Design: A total of 58 keratin-producing odontogenic cysts, diagnosed over ten years and classified according to the WHO 2005 criteria, were immunohistochemically analyzed in terms of CCD1 expression, which was quantified in the basal, suprabasal and intermediate/superficial epithelial compartments. The extent of immunostaining was measured as a proportion of total epithelial thickness. Quantified immunohistochemical data were correlated with clinicopathological features and clinical recurrence. Results: Keratin-producing odontogenic cysts were classified as 6 syndromic keratocystic odontogenic tumors (S-KCOT), 40 sporadic or non-syndromic KCOT (NS-KCOT) and 12 orthokeratinized odontogenic cysts (OOC). Immunohistochemically, CCD1 staining was evident predominantly in the parabasal region of all cystic lesions, but among-lesion differences were apparent, showing a clear expansion of parabasal compartment especially in the S-KCOT, followed to a lesser extent in the NS-KCOT, and being much more reduced in the OOC, which had the greatest average epithelial thickness. Conclusions: The differential expression of CCD1 noted in the present study suggests that dysregulation of cell cycle progression from G1 to the S phase contributes to the different aggressiveness of these lesions. However, CCD1 expression levels did not predict NS-KCOT recurrence, which is likely influenced by factors unrelated to lesion biology. Key words:Keratin-producing odontogenic cyst, keratocyst, keratocystic odontogenic tumor, nevoid basal cell carcinoma syndrome, orthokeratinized odontogenic cyst, cyclin D1, immunohistochemistry.     

Intra-osseous lesions in Greek children and adolescents. A study based on biopsy material over a 26-year period

OBJECTIVE: The purpose of this retrospective study was to investigate the spectrum of oral intra-osseous lesions in a Greek population, consisting of children and adolescents under 18 years of age. MATERIAL AND METHODS: Data was obtained from the histopathological reports that accompanied biopsy request forms, which were retrieved from the files of the Oral Pathology Department, Faculty of Dentistry, University of Athens, during a 26-year period. A retrospective analysis with respect to patients' age and gender, frequency and location of the lesions was performed. The lesions were classified into cystic (odontogenic and non-odontogenic) and solid lesions (odontogenic and non-odontogenic). The patients were divided into three age groups: a) 0-6 years old, b) 7-12 years old and c) 13-18 years old. RESULTS: 474 intra-osseous lesions were detected and represented 2.38% out of a total of 19933 biopsies. Male/female ratio was 1.25/1. The majority of the lesions was located in the mandible (49.8%) and occurred in the third age group of patients (58.7%). Odontogenic cysts represented the most frequent intraosseous lesion (64.1%) followed by non-odontogenic solid lesions representing 22.5% of the intra-osseous population. The most frequently encountered lesions in descending order were radicular (36.3%) and dentigerous (18%) cysts, keratocysts (9.5%), apical granulomas (7.6%), odontomas (6%) and fibrous dysplasia (5%). Only 6 malignant lesions were reported (1.3%). CONCLUSIONS: This clinicopathologic study revealed that a broad spectrum of mostly benign bony lesions may occur during childhood.     

Granular cell — Peripheral ameloblastoma: a rare variant

Ameloblastoma is an epithelial odontogenic tumour of the jaw and exhibits diverse microscopic patterns which occurs either singly or in combination with other patterns. Peripheral ameloblastoma is a rare odontogenic soft tissue tumor, derived from epithelial and/or mesenchymal elements being part of the tooth-forming apparatus. The lesions responsible for approximately 1% to 5% of all cases of ameloblastoma affecting alveolar mucosa and gingiva occurring mainly, in the middle age. This article describes a case of peripheral ameloblastoma affecting a 35-year-old female. The lesion was located in the right buccal space. The occurrence and pathogenesis of peripheral ameloblastomas in general, are reviewed. The tumour was excised and no recurrence has been observed after twenty four months of surgery.     

Epidemiological study of intraosseous lesions of the stomatognathic or maxillomandibular complex diagnosed by a Reference Centre in Brazil from 2006–2017

This epidemiological study was designed to find out the incidence and factors associated with the occurrence of intraosseous lesions diagnosed at a Reference Centre in Brazil. We included all patients diagnosed with intraosseous lesions (cyst, tumour, bone-associated lesion, and periapical disease) during the period 2006–2017, and analysed the association between some sociodemographic and clinical variables and the types of lesion. There was a total of 290 intraosseous lesions, the most common being odontogenic cysts. There was a significant association between age and odontogenic tumours (p = 0.001). In relation to the histopathological diagnosis, root cysts were the most common (n = 57), followed by dentigerous cysts (n = 26). The lesions studied were seen most often in women between the second and fourth decades of life, odontogenic cysts being the most common type found. We know of few publications of similar epidemiological work, either in Brazil or in the rest of the world, so we suggest that more such studies are made.