Clinicopathological Profile of 80 Cases of Unicystic Ameloblastoma Aided by a Histopathological Comparison Using Modified Philipsen-Reichart Classification and Marx-Stern Classification.

Unicystic ameloblastoma (UA) is an uncommon variant of ameloblastoma and behaves totally different from the solid multicystic variant of ameloblastoma (SMA); furthermore the histological subgroups of UA also show varied behavior regarding proliferation. The present multi-centric study was designed to present the clinicopathological features of unicystic ameloblastoma (UA) and to compare the two popular histological classifications systems. 80 satisfactory cases of UA were retrieved and evaluated for clinicopathological parameters from four teaching dental schools of North India. The cases were classified using modified Reichart and Philipsen system and Marx and Stern system followed by comparison of inter-observer variability. The results were analyzed using SPSS software. The mean age of occurrence was 30.79 ± 16.49 years. Males outnumbered females (M:F::1.67:1). The majority of cases occurred in the third decade irrespective of the gender. Most cases were found in body-angle-ramus region of the mandible. The modified Reichart and Philipsen classification yielded better interobserver agreement (kappa value 0.845). The modified Reichart and Philipsen classification yields better inter-rater agreement and is easy to reproduce amongst oral pathologists. Being simpler it may easily be understood by the operating surgeon for better treatment outcome.

Immunohistochemical expression of p53 and murine double minute 2 protein in odontogenic keratocyst versus variants of ameloblastoma.

INTRODUCTION: Oncogenes and tumor suppressor genes play a major role in cancer formation, growth, and progression. One of the important findings in this area is that murine double minute 2 (MDM2) oncogene is a negative regulator of wild-type p53. In tumors, expressing wild-type p53, inhibition of MDM2 expression will stabilize p53 and allow it to perform its proapoptotic function, while simultaneously preventing MDM2 from exerting its p53-independent oncogenic effects. The intracellular levels of p53 are tightly regulated by MDM2, as it is a key player in autoregulatory feedback loop under nonstressed conditions. The p53-MDM2 relationship is vital not only for essential functions of the cell, but it also appears to be an integrated part of the complex cellular network which supports the importance of this affair and is a hallmark for its coexistence. SUBJECTS AND METHODS: This study was designed to identify immunohistochemically the expression of p53 and MDM2 gene using monoclonal antibody in 60 cases of formalin-fixed paraffin-embedded tissue blocks, of which 20 cases were of solid multicystic ameloblastoma (SMA), 20 cases were of odontogenic keratocyst (OKC), and 20 cases were of unicystic ameloblastoma (UA). RESULTS: Immunoexpression of p53 and MDM2 was highest in OKC followed by SMA and was minimum in UA. Further results showed positive correlation between both the molecules. CONCLUSION: The studied showed that the relationship has a significant role in cancer etiology and progression and therefore is an important topic for future research which should help in the development of new therapeutic agent against cancer.

Recurrence factors in pediatric ameloblastoma: Clinical features and a new classification system.

BACKGROUND: Ameloblastomas of jaw in the pediatric population are a rare clinical entity and have not been well addressed in the literatures. The present retrospective study analyzed the risk factors associated with recurrence of pediatric ameloblastomas. METHODS: Cases of primary pediatric ameloblastomas seen in a tertiary hospital between 2005 and 2015 were analyzed to identify the clinical factors associated with recurrence. RESULTS: There were a total of 104 cases of primary pediatric ameloblastomas. The overall mean maximum tumor diameter was 4.11 ± 1.339 cm. The receiver operating characteristic curve and the Youden Index showed an optimal cutoff point of 4.95 cm to accurately predict recurrence. Bone cortex/soft tissue invasion were associated with tumor recurrence (P < .001). CONCLUSIONS: The maximum tumor diameter, root resorption, and bone cortex/soft tissue invasion were risk factors for recurrence of pediatric ameloblastomas. The new classification system may serve as a predictor of recurrence in pediatric ameloblastomas.

Expression of proteoglycans in two types of ameloblastoma: novel Immunohistochemical findings.

Alterations in cellular and extracellular matrix components play an important role during tumorigenesis; proteoglycans are included among these components. Ameloblastomas are odontogenic tumors distinguished as invasive and infiltrative neoplasms and are divided into different histological types, the most common of which are the unicystic ameloblastoma and the conventional ameloblastoma. The aim of this study was to identify the presence of two proteoglycans, perlecan and biglycan, in different types of ameloblastoma. Using immunohistochemistry, we determined the presence of both proteins in 28 unicystic ameloblastomas and 23 conventional ameloblastomas. We identified the cytoplasmic and nuclear presence of perlecan and the cytoplasmic presence of biglycan in both types of ameloblastoma. The mean values of immunoexpression were higher in the conventional type compared to the unicystic type. Neither the presence of biglycan in ameloblastomas nor the nuclear presence of perlecan in any odontogenic tumor has previously been reported. The differential immunoexpression of perlecan and biglycan in these types of ameloblastomas suggests their participation in the developmental process of these tumors.

Chondroblastic and fibroblastic osteosarcoma of the jaws: Report of two cases and review of literature.

This study aims to report of two variants of gnathic osteosarcoma with highlights on the varied histopathological presentation of osteosarcomas (OS). OS present with diverse histological appearances. Despite significant advances in molecular pathogenesis and biomarkers, clinicopathologic correlation is still considered as the important criteria in diagnosis. Chondroblastic osteosarcoma in a 52-year-old female and fibroblastic osteosarcoma in a 35-year-old female. Osteosarcoma is a relatively rare disease of the oral and maxillofacial region. Regular screening and follow-up is highly recommended, as recurrence rates are higher. Thorough understanding of the histologic spectrum of osteosarcoma reduces the diagnostic difficulties in categorizing the OS and separating these neoplasms from benign bone diseases.

Prevalence profile of odontogenic cysts and tumors on Brazilian sample after the reclassification of odontogenic keratocyst.

PURPOSE: The aim of this study was to evaluate the impact of the reclassification of odontogenic keratocyst (OKC) as a tumor on the prevalence profile of odontogenic cysts (OCs) and odontogenic tumors (OTs). STUDY DESIGN: Two referral Oral and Maxillofacial Pathology services in Brazil were evaluated. All cases diagnosed as OCs or OTs were selected and classified according to the 1992 WHO-classification (cases before 2005 WHO classification of tumors excluding OKC) and the 2005 WHO classification of tumors, going forward including cases of odontogenic keratocyst tumor (KCOT). The frequency and prevalence of OCs and OTs were compared before and after the reclassification. RESULTS: Among 27,854 oral biopsies, 4920 (17.66%) were OCs and 992 (3.56%) were OTs. The prevalence of OTs before 2005 WHO classification of tumors was 2.04%, while the prevalence after 2005 WHO classification was 11.51% (p < 0.0001). Before 2006, the most frequent tumor diagnosed was odontoma with 194 cases (39.67%), and after 2005 WHO classification of tumors the KCOT was the most frequent with 207 cases (41.07%). CONCLUSIONS: The increase in the prevalence of OTs after 2005 WHO is related to the improvement of pathology services and to the inclusion of KCOT in the OTs group.

Epidemiological study of odontogenic tumours: An institutional experience.

Epidemiological studies on odontogenic tumours conducted in different parts of the world emphasised variation in incidence and distributional pattern. Such epidemiological studies are obscured in Southern state of Andhra Pradesh in India. Present study was conducted at an institutional setup in South Indian population to assess the demographic data of odontogenic tumours. The retrospective study, which included all the odontogenic tumours from the archives of department of oral pathology, Dental teaching and Research Institution in southern part of India. Cases were selected based on the classification of WHO 2005 histopathological typing for odontogenic tumours and the assessment year considered was from 2002 to 2014. Demographic data was analysed for these tumours. Results were analysed using Chi-Square Test. Incidence of the odontogenic tumours was found to be 2.17%. Peak age incidence was recorded highest in third and fourth decade of life. Males were commonly involved [59%] with the male to female ratio of 1.43:1. Posterior mandible [53.4%] was the chief anatomical location involved with the tumours. Considering the individual lesions, Ameloblastoma [49%] was found to be more frequent, followed by Keratinizing cystic odontogenic tumour [32%], Odontome [6.2%], Adenomatoid odontogenic tumour [5.5%], Odontogenic myxoma [2.4%], Ameloblastic fibroma [0.6%], Calcifying epithelial odontogenic tumour [1.8%] and Squamous odontogenic tumour [1.2%]. The total frequency of odontogenic tumours was 2.17%. Ameloblastoma and Keratinizing cystic odontogenic tumours were the predominant tumours, demonstrating significant regional and geographic variation.

Peripheral calcifying cystic odontogenic tumour and peripheral dentinogenic ghost cell tumour: an updated systematic review of 117 cases reported in the literature.

PURPOSE: To integrate the available data published on peripheral calcifying cystic odontogenic tumour (CCOT) and peripheral dentinogenic ghost cell tumour (DGCT) into a comprehensive analysis of its clinical and radiologic features. METHODS: An electronic search was undertaken in May, 2016. Eligibility criteria included publications reporting cases of peripheral CCOTs/DGCTs having enough clinical, radiological and histological information to confirm a definite diagnosis. Demographic data, lesion site and size, treatment approach and recurrence were analyzed. RESULTS: Hundred and thirty-eight lesions were found (65 publications), and 117 lesions (63 publications) with enough information were analyzed (55 CCOTs, 50 DGCTs, 12 unknown). Mean age of patients was 51.3 ± 23.4 (min-max, 1-92), with higher mean age for the DGCTs variant. The lesions were more prevalent in the mandible, anterior region of the jaws, and in the second, sixth and eighth decades, with an equal sexual distribution. About 20% of all lesions showed signs of erosion of the underlying bone, with a higher rate for DGCTs. The mean lesion size was 1.3 ± 0.8 (min-max, 0.4-3.0). Time of follow-up was informed for 37 lesions, with a mean ± SD of 30.2 ± 21.0 months (min-max, 6-84). Almost all lesions were treated by conservative surgery; only three recurrences were reported. CONCLUSIONS: Peripheral CCOTs/DGCTs are rare lesions. Most of the lesions were treated by simple excision with or without curettage of the underlying bone. As the recurrence rate is very low, a conservative approach seems to be enough for the great majority of cases.

Intraosseous haemangioma: semantic and medical confusion.

The literature is rich in case reports of intraosseous haemangioma, although most of these are actually cases of venous or capillary malformations. To illustrate this confusion in terminology, we present three cases of slow-flow vascular malformations misnamed as intraosseous haemangioma. A retrospective study of children diagnosed with intraosseous haemangioma was conducted. Clinical and radiological data were evaluated. Histopathological examinations and immunohistochemical studies were redone by three independent pathologists to classify the lesions according to the International Society for the Study of Vascular Anomalies (ISSVA) and World Health Organization (WHO) classifications. Three children who had presented with jaw haemangiomas were identified. Computed tomography scan patterns were not specific. All tumours were GLUT-1-negative and D2-40-negative. The lesions were classified as central haemangiomas according to the WHO, and as slow-flow malformations according to the ISSVA. The classification of vascular anomalies is based on clinical, radiological, and histological differences between vascular tumours and malformations. Based on this classification, the evolution of the lesion can be predicted and adequate treatment applied. The binary ISSVA classification is widely accepted and should be applied for all vascular lesions.

Differential expression of glypican-1 in ameloblastoma variants.

Although benign, ameloblastomas are locally invasive and destructive tumors of the jawbones. The glypicans comprise a family of glycosylphosphatidylinositol-anchored proteoglycans that, by virtue of their cell-surface localization and heparin sulfate chain composition, might regulate the response of cells to numerous heparin-binding growth factors, cell adhesion molecules, and extracellular matrix components. The expression of glypican-1 is differentially altered among different types of malignancies, suggesting a possible role in the tumorigenesis and biological behavior of these neoplasms. The aim of this study was to determine the expression of glypican-1 and then hypothesize the possible role that this protein may play in the biological behavior of ameloblastomas. We assessed the presence of glypican-1 by immunohistochemical staining analyses in a series of 80 cases of different types of ameloblastomas. Desmoplastic ameloblastomas exhibited the highest expression of glypican-1 (100%), followed by the peripheral (66%), solid/multicystic (51.2%), and unicystic (47.2%) types, showing statistically significant differences among them (P<0.001). Differences detected in glypican-1 expression among different subtypes of ameloblastomas, could be suggesting a possible association with their different biological behavior.

Primordial odontogenic tumour: clinicopathological analysis of six cases of a previously undescribed entity.

AIM: To describe the clinicopathological and immuno-histochemical features of six tumours that do not fulfil the criteria of any of the currently classified odontogenic tumours. METHODS AND RESULTS: The patients were three males and three females, whose ages ranged from 3 years to 18 years (mean, 11.05 years). In all cases there were well-defined radiolucencies associated with unerupted teeth apparently showing a pericoronal relationship. Microscopically, all tumours were composed of variably cellular loose fibrous tissue with areas similar to dental papilla, entirely surrounded by cuboidal to columnar epithelium resembling the internal epithelium of the enamel organ. Mesenchymal tissue was positive only for vimentin, and Ki67 expression was very low (<2%). The epithelium was positive for CK AE1/AE3, CK5, CK14, and CK19, but negative for CK18 and CK20. All cases showed clear demarcation from the surrounding bone, and were surgically removed, with no recurrences after follow-up ranging from 6 months to 20 years. CONCLUSIONS: These findings differ from those observed in other odontogenic lesions, such as ameloblastic fibroma, odontogenic myxoma, odontogenic fibroma, and hyperplastic dental follicles. The term primordial odontogenic tumour is proposed to describe this novel lesion.

Computed tomographic characteristics of odontogenic neoplasms in dogs.

Odontogenic neoplasms are locally invasive oral tumors in dogs. The purpose of this retrospective study was to describe CT characteristics for varying histopathologic types of canine odontogenic neoplasms. A board-certified veterinary radiologist who was unaware of histologic findings reviewed and scored imaging studies. A total of 29 dogs were included in the study. Twenty-three of these dogs had concurrent dental radiographs. The most common CT characteristics for all tumor types were a direct association with or in the region of multiple teeth in 96.4% (27/28), contrast enhancement in 96.3% (26/27), alveolar bone lysis in 93.1% (27/29), and mass-associated tooth displacement in 85.2% (23/27). Mass-associated cyst-like structures were identified in 53.6% (15/28) and were only present in tumors containing odontogenic epithelium. Canine acanthomatous ameloblastomas (n = 15) appeared as extra-osseous (10/15) or intra-osseous (5/15) masses. Intra-osseous canine acanthomatous ameloblastomas were more likely to have mass-associated cyst-like structures and were subjectively more aggressive when compared with extra-osseous canine acanthomatous ameloblastomas. Amyloid-producing odontogenic tumors (n = 3) had subjectively uniform CT imaging characteristics and consisted of round soft tissue and mineral attenuating masses with multiple associated cyst-like structures. Fibromatous epulides of periodontal ligament origin (n = 4) were contrast enhancing extra-osseous masses that were rarely referred for CT examinations and 25% (1/4) were not visible with CT. Other odontogenic tumors were less represented or had more variable CT imaging characteristics. Mass-associated tooth destruction was appreciated more often with dental radiographs and extra-oral tumor extension was identified more often with CT.

Expression of cell cycle and apoptosis-related proteins in ameloblastoma and keratocystic odontogenic tumor.

Tumors arising from epithelium of the odontogenic apparatus or from its derivatives or remnants exhibit considerable histologic variation and are classified into several benign and malignant entities. A high proliferative activity of the odontogenic epithelium in ameloblastoma (AM) and keratocystic odontogenic tumor (KCOT) has been demonstrated in some studies individually. However, very few previous studies have simultaneously evaluated cell proliferation and apoptotic indexes in AM and KCOT, comparing both lesions. The aim of this study was to assess and compare cell proliferation and apoptotic rates between these two tumors. Specimens of 15 solid AM and 15 KCOT were evaluated. The proliferation index (PI) was assessed by immunohistochemical detection of Ki-67 and the apoptotic index (AI) by methyl green-pyronin stain. KCOT presented a higher PI than AM (P < .05). No statistically significant difference was found in the AI between AM and KCOT. PI and AI were higher in the peripheral cells of AM and respectively in the suprabasal and superficial layers of KCOT. In conclusion, KCOT showed a higher cell proliferation than AM and the AI was similar between these tumors. These findings reinforce the classification of KCOT as an odontogenic tumor and should contribute to its aggressive clinical behavior.

Diagnostic value of MRI for odontogenic tumours.

OBJECTIVES: To evaluate the diagnostic value of MRI for odontogenic tumours. MATERIALS AND METHODS: 51 patients with odontogenic tumours were subjected to pre-operative MRI examinations. For tumours with liquid components, i.e. ameloblastomas and keratocystic odontogenic tumours (KCOTs), the signal intensity (SI) uniformity of their cystic components (UΣ) was calculated and then their UΣ values were compared. For tumours with solid components that had been examined using dynamic contrast-enhanced MRI (DCE-MRI), their CImax (maximum contrast index), Tmax (the time when CImax occurred), CIpeak (CImax × 0.90), Tpeak (the time when CIpeak occurred) and CI300 (i.e. the CI observed at 300 s after contrast medium injection) values were determined from CI curves. We then classified the odontogenic tumours according to their DCE-MRI parameters. RESULTS: Significant differences between the UΣ values of the ameloblastomas and KCOT were observed on T1 weighted images, T2 weighted images and short TI inversion recovery images. Depending on their DCE-MRI parameters, we classified the odontogenic tumours into the following five types: Type A, CIpeak > 2.0 and Tpeak < 200 s; Type B, CIpeak < 2.0 and Tpeak < 200 s; Type C, CI300 > 2.0 and Tmax < 600 s; Type D, CI300 > 2.0 and Tmax > 600 s; Type E, CI300 < 2.0 and Tmax > 600 s. CONCLUSION: Cystic component SI uniformity was found to be useful for differentiating between ameloblastomas and KCOT. However, the DCE-MRI parameters of odontogenic tumours, except for odontogenic fibromas and odontogenic myxomas, contributed little to their differential diagnosis.

Primary jaw tumors in children.

PURPOSE: To document tumor type, biological/clinical behavior, management, and outcomes in children with primary jaw tumors. MATERIALS AND METHODS: A retrospective analysis of children with primary benign jaw tumors evaluated at Massachusetts General Hospital and Children's Hospital Boston from 1991 to 2009 was conducted. Patients were included if they were aged 16 years or younger and had adequate records and follow-up. Patient charts, radiographs, and pathology reports were reviewed. Demographic data; clinical, radiographic, and histopathologic findings; treatment; and outcomes were recorded. Predictor variables were tumor type, clinical behavior (nonaggressive/aggressive), and treatment. Outcome variables included presence or absence of recurrence and complications. Descriptive statistics were computed. RESULTS: There were 102 patients (44 male and 58 female patients) with a mean age of 8.3 years (range, 6 months to 16 years). Tumors were grouped by tumor type: mesenchymal (n=96), neurogenic (n=5), vascular (n=5), or hematopoietic (n=3); in addition, when appropriate, they were classified as nonaggressive (n=54) or aggressive (n=27). Treatment was based on the tumor's clinical/biological behavior and radiographic features and whether it was solitary or multifocal. Patients with nonaggressive tumors were treated by enucleation, debulking/contouring, or observation, and the recurrence rate was 0%. Aggressive tumors underwent en bloc resection or enucleation with systemic adjuvant therapy, and the recurrence rate was 7.1%. Mean follow-up was 2.4 years. CONCLUSIONS: The results of this study indicate that primary jaw tumors in children exhibit variable biological/clinical behavior, often not predicted by descriptive histologic findings. Management of these tumors should therefore be guided by clinical/biological behavior.

The keratocystic odontogenic tumor.

In 2005, the World Health Organization renamed the lesion previously known as an odontogenic keratocyst as the keratocystic odontogenic tumor. The clinical features associated with the keratocystic odontogenic tumor show it to be a unilocular or multilocular radiolucency, occurring most frequently in the posterior mandible. These tumors are normally diagnosed histologically from a sample of the lining. With simple enucleation, it seems that the recurrence rate may be from 25% to 60%.

A classification system for recurrent ameloblastoma of the jaws--review of 30 cases in Nigerians.

This paper reviewed the clinicopathologic presentation of recurrent ameloblastoma in 30 Nigerian patients at three tertiary referral centers with the sole objective of developing a classification system. Most recurrences occurred in patients in their 3rd decade of life (20-29years) and males were more frequently affected than females (1.5 to 1). Though enucleation resulted in the highest rate of recurrences (30%), hemi-mandibulectomy also resulted in a 20% recurrence rate. Majority of the recurrences occurred within 5 to 9 years after primary surgery. Most primary jaw sites of the lesion corresponded with the primary jaw sites of the recurrent tumor which in itself may be a reflection of inadequate primary treatment. The most frequent anatomic site of primary tumors that recurred was c4 (highest level of ramus involvement). The most frequent anatomic classification of the recurrent tumors was recurrence at one bone margin (Bla) and recurrence at intervening /adjacent soft tissues between the resected bone edges (Blc). Mandible to maxilla recurrence increases the likelihood of extension to the skull and brain.

Radiopaque jaw lesions: an approach to the differential diagnosis.

Radiopaque jaw lesions are frequently encountered at radiography and computed tomography, but they are usually underevaluated or underdescribed in radiology reports. A systematic approach to the evaluation of radiopaque jaw lesions is necessary to diagnose the lesion or at least provide a meaningful differential diagnosis. To evaluate a radiopaque jaw lesion, the first, most important step is to categorize the lesion according to its attenuation, its relationship to the teeth, and its location with respect to the tooth. These basic observations are essential to the evaluation of any type of jaw lesion. Once these observations have been made, it is easy to create a proper differential diagnosis. The presence of important characteristics, such as margination, a perilesional halo, bone expansion, and growth pattern, as well as whether the lesion is sclerotic, has ground-glass attenuation, or is mixed lytic and sclerotic, further narrows the differential diagnosis. It is important to note that some radiopaque jaw lesions may be entirely lucent early in their evolution. Awareness of the demographic distribution of these lesions and their associated clinical features, as well as the radiologic approach, is important to explore the "terra incognita" of radiopaque jaw lesions.

Synchronous ossifying fibromas of the jaws: a review.

According to the World Health Organization, it is proposed that benign fibro-osseous lesions be divided into 3 categories, including fibrous dysplasia, ossifying fibroma (OF), and osseous dysplasia. OF arises from the periodontal ligament, which contains multipotential cells. These benign tumors may become large and aggressive. Slow growth and lack of symptoms are the cardinal features. OF tends to occur in the second and third decades of life, with predilection for women and for the mandibular premolar-molar area. The method of treatment used for large or rapidly expanding lesions is surgical removal (enucleation). Rarely, OFs occur multifocally. We report a 20-year-old man with synchronous OFs of his maxilla and mandible and review other synchronous cases reported. Such lesions can be properly diagnosed and treated by correlating radiographic, clinical, surgical, and histopathologic findings.