Conservative treatment of ameloblastoma: report of 2 cases and review of the literature

Introduction: ameloblastomas correspond to one of the most prevalent odontogenic tumors in developing countries, they are mainly located in the mandible, and their treatment has been widely discussed over the years, using radical or conservative treatments depending on different variables. Clinical case: we present two cases of patients with ameloblastoma who underwent conservative treatment without the use of adjuvant therapy, obtaining satisfactory results at 36 and 48 months. Discussion: due to a possible recurrence with conservative treatment, radical management has been suggested, however, the choice of treatment should be based on a series of clinical, histological, and radiographic characteristics.

Introducción: Los ameloblastomas corresponden a uno de los tumores odontogénicos más prevalentes en los países en desarrollo, se ubican principalmente en la mandíbula, y su tratamiento ha sido ampliamente discutido a lo largo de los años, utilizando tratamientos radicales o conservadores dependiendo de distintas variables. Caso clínico: se presentan dos casos de pacientes con un ameloblastoma a quienes se les realizó tratamiento conservador sin uso de terapia coadyuvante, obteniendo resultados satisfactorios a los 36 y 48 meses. Discusión: Debido a una posible recurrencia con un tratamiento conservador, se ha sugerido manejo radical, sin embargo, la elección de tratamiento debe ser en base a una serie de características clínicas, histológicas y radiográficas.

Complicações pós-operatórias relacionadas a ressecção do ameloblastoma / Postoperative complications related to ameloblastoma / Complicaciones postoperatorias relacionadas con la resección de ameloblastoma

A ressecção é o tratamento de escolha para tratamento do ameloblastoma, este que é o tumor odontogênico mais comuns, excluindo os odontomas. A desregulação de diversos genes no desenvolvimento de dentes pode desempenhar papel em sua histogênese. Alguns eventos adversos podem ocorrer durante seu tratamento pós-operatório. Recidivas ocorrem porque o ameloblastoma tende a se infiltrar entre o trabeculado ósseo esponjoso intacto na periferia do tumor antes que a reabsorção óssea se torne radiograficamente evidente. Consequentemente, a margem real do tumor sempre se estende além da sua imagem radiográfica ou da margem clínica. Deiscência de sutura é uma complicação que pode ocorrer no pós-operatório imediato na qual as bordas da ferida, que estão unidas por uma sutura, acabam se abrindo, aumentando o risco de infecção e dificultando assim a cicatrização. Fratura de placa de reconstrução é um evento possível de ocorrer em tratamentos de grandes defeitos. O estresse causado pela modelagem da placa durante a conformação da placa, além da ação muscular são uns dos fatores que pode fragilizar o metal da placa. Outras complicações podem ocorrer como: assimetrias, parestesia temporária e permanente do nervo alveolar inferior e deficiência estética e funcional. As descrições destes eventos na literatura ajudam aos clínicos conhecer e tentá-lo preveni-lo e com saber tratar... (AU)

Resection is the treatment of choice for treating ameloblastoma, which is the most common odontogenic tumor, excluding odontomas. The dysregulation of several genes in the development of teeth may play a role in their histogenesis. Some adverse events may occur during your postoperative treatment. Relapses occur because ameloblastoma tends to infiltrate between intact cancellous bone trabeculae at the pe riphery of the tumor before bone resorption becomes radiographi cally evident. Consequently, the actual tumor margin always extends beyond its radiographic image or clinical margin. Suture dehiscence is a complication that can occur in the immediate postoperative period in which the edges of the wound, which are joined by a suture, end up opening, increasing the risk of infection and thus hindering healing. Reconstruction plate fracture is a possible event to occur in large de fect treatments. The stress caused by the modeling of the plate during the formation of the plate, in addition to muscle action, are one of the factors that can weaken the plate metal. Other complications may occur, such as: asymmetries, temporary and permanent paresthesia of the inferior alveolar nerve and aesthetic and functional deficiency. The descriptions of these events in the literature help clinicians to Resection is the treatment of choice for treating ameloblastoma, which is the most common odontogenic tumor, excluding odontomas. The dysregulation of several genes in the development of teeth may play a role in their histogenesis. Some adverse events may occur during your postoperative treatment. Relapses occur because ameloblastoma tends to infiltrate between intact cancellous bone trabeculae at the pe riphery of the tumor before bone resorption becomes radiographi cally evident. Consequently, the actual tumor margin always extends beyond its radiographic image or clinical margin. Suture dehiscence is a complication that can occur in the immediate postoperative period in which the edges of the wound, which are joined by a suture, end up opening, increasing the risk of infection and thus hindering healing. Reconstruction plate fracture is a possible event to occur in large de fect treatments. The stress caused by the modeling of the plate during the formation of the plate, in addition to muscle action, are one of the factors that can weaken the plate metal. Other complications may occur, such as: asymmetries, temporary and permanent paresthesia of the inferior alveolar nerve and aesthetic and functional deficiency. The descriptions of these events in the literature help clinicians to know and try to prevent them and to know how to treat them... (AU)

La resección es el tratamiento de elección para tratar el ameloblastoma, que es el tumor odontogénico más común, excluyendo los odontomas. La desregulación de varios genes en el desarrollo de los dientes puede desempeñar un papel en su histogénesis. Algunos eventos adversos pueden ocurrir durante su tratamiento postoperatorio. Las recaídas ocurren porque el ameloblastoma tiende a infiltrarse entre las trabéculas del hueso esponjoso intacto en la periferia del tumor antes de que la reabsorción ósea sea evidente en las radiografías. En consecuencia, el margen tumoral real siempre se extiende más allá de su imagen radiográfica o margen clínico. La dehiscencia de sutura es una complicación que puede ocurrir en el postoperatorio inmediato en el que los bordes de la herida, que están unidos por una sutura, acaban abriéndose, aumentando el riesgo de infección y dificultando así la cicatrización. La fractura de la placa de reconstrucción es un evento posible que ocurre en los tratamientos de defectos grandes. Los esfuerzos que provoca el modelado de la placa durante la conformación de la placa, además de la acción muscular, son uno de los factores que pueden debilitar la placa metálica. Pueden presentarse otras complicaciones como: asimetrías, parestesias temporales y permanentes del nervio alveolar inferior y deficiencia estética y funcional. Las descripciones de estos eventos en la literatura ayudan a los clínicos a conocerlo y tratar de prevenirlo y saber cómo tratarlo... (AU)

Macro and microscopic study of a rare case of Papilliferous Keratoameloblastoma using a stereo zoom microscope

Papilliferous keratoameloblastoma is an extremely rare variant of ameloblastoma, a benign odontogenic tumor, with only seven cases reported in the English language literature. This variant presents with the metaplastic transformation of stellate reticulum-like cells to the extent of forming papillary structures exhibiting superficial keratinization of varying thickness. This paper describes the pathognomonic macroscopic features of this tumor observed during gross examination under the stereo zoom microscope that differentiate it from the other odontogenic tumors which have not been explored in the previously documented cases. Also, in this paper, a detailed comparison of the macroscopic features observed under the stereo zoom microscope during gross examination with the microscopic features of the histologic section has been described proving to be useful in the histological differential diagnosis of the keratinizing variants of ameloblastoma.

Detection and evaluation of the presence of the BRAF V600E mutation in ameloblastomas in an Indian population

Introduction: Ameloblastoma is a benign epithelial odontogenic neoplasm that constitutes approximately 1% of all oral tumors and about 9 to 11% of all odontogenic tumors. They are slow-growing, locally invasive, and demonstrate a potential for metastasis and malignant transformation. The molecular pathogenesis of ameloblastoma is attributed to aberrant activity of the signal transduction pathways relating to developmental stages of odontogenesis including the mitogen-activated protein kinase (MAPK) pathway. The BRAF V600E mutation was identified as the most frequently mutated gene in this neoplasm. Studies have shown that use of BRAF inhibitors in patients diagnosed with ameloblastomas led to a significant reduction in tumor volume. Aims: To detect the expression of BRAF V600E mutation in ameloblastomas in an Indian population using immunohistochemistry. To compare the difference in the occurrence of the BRAF V600E mutation between mandibular and maxillary cases. Materials and Methods: Thirty-three formalin-fixed paraffin-embedded tissues of histopathologically proven cases of ameloblastoma were assessed for the BRAF V600E mutation by immunohistochemistry using the BRAF V600E monoclonal antibody. Patient data such as age, sex, anatomical site, recurrence were documented. Statistical Analysis: The statistical analysis was performed using the Pearson Chi-square test and Student's t-test. Results: The present study revealed a high expression of the BRAFV600E mutation in mandibular cases of ameloblastoma among Indians irrespective of the age, sex, site, recurrence or histological pattern. Conclusions: The identification of this driver mutation opens the possibility of an adjuvant therapeutic modality to reduce the significant facial disfigurement and morbidity following surgical management.

Análisis inmunohistoquímico de MMP-1, MMP-2 y MMP-9 en ameloblastoma convencional / Immunohistochemical analysis of MMP-1, MMP-2, MMP-9 in conventional ameloblastoma

Introducción: las metaloproteinasas son enzimas que participan en la remodelación tisular y su función se relaciona con procesos fisiológicos y patológicos, como la invasión y la metástasis. El ameloblastoma convencional (AMC) es una neoplasia epitelial benigna odontogénica intraósea caracterizada por una progresión lenta y localmente invasiva, cuyo crecimiento se ha vinculado con el recambio ósea y la remodelación de la matriz extracelular. El objetivo del presente trabajo fue determinar la presencia inmunohistoquímica de MMP-1, MMP-2 y MMP-9 en el AMC. Material y métodos: se realizó un estudio piloto observacional analítico utilizando cinco muestras de AMC. Los especímenes fueron recolectados aleatoriamente del archivo del Departamento de Patología Oral y Maxilofacial, de la Escuela Nacional de Estudios Superiores (ENES) Unidad León, UNAM. Como grupo control se emplearon dos especímenes de folículo dental, obtenido de pacientes con indicación de su extracción por motivos ortodóncicos. Se realizó la técnica de inmunohistoquímica por peroxidasa, recolectando el nivel y proporción de inmunoexpresión de manera semicuantitativa. Resultados: cuatro pacientes fueron de género masculino y uno femenino, la edad promedio fue de 40.6 ± 14.9 años. Todas las muestras fueron obtenidas de la región mandibular posterior. Se observaron dos especímenes con patrón folicular y tres con plexiforme. Las MMP-2 y MMP-9 se detectaron sólo en uno de los cinco especímenes y únicamente en el parénquima de la lesión, con una proporción de 100%. Conclusión: según nuestro análisis inmunohistoquímico, las MMP-2 y MMP-9 son las metaloproteinasas que presentaron expresión positiva dentro de la patogénesis del AMC comparado a la MMP-1; no obstante, es necesario realizar este tipo de estudios en una población mayor (AU)

Introduction: metalloproteinases are enzymes involved in tissue remodeling and their function is related to physiological and pathological processes, such as invasion and metastasis. These enzymes are capable of degrading components of the extracellular matrix, which may promote tumor progression. Conventional ameloblastoma (CA) is described as a benign intraosseous epithelial odontogenic neoplasm characterized by a slow and locally invasive progression, whose growth has been linked to bone turnover and extracellular matrix remodeling. The aim of the present work was to determine the immunohistochemical presence of MMP-1, MMP-2 and MMP-9 in CA. Material and methods: an analytical observational pilot study was performed using 5 CA, randomly collected from the archive of the Department of Oral and Maxillofacial Pathology, Escuela Nacional de Estudios Superiores (ENES) Unidad León, UNAM. The control group used were two dental follicle samples, obtained from patients with extraction indication for orthodontic treatment. The peroxidase immunohistochemistry assay was performed, collecting semiquantitatively level and proportion of immunoexpression. Results: four patients were male and one female, the average age was 40.6 ± 14.9 years. All specimens were obtained from the posterior mandibular region. Two specimens were observed with follicular pattern and three with plexiform pattern. MMP-2 and MMP-9 were detected only in one of the five specimens, with presence in the parenchyma of the lesion, with a proportion of 100% of the cell analyzed. Conclusion: according to our immunohistochemical analysis, MMP-2 and MMP-9 are the metalloproteinases that presented positive expression within the pathogenesis of CA compared to MMP-1; however, it is necessary to perform this type of studies in a larger population (AU)

Ameloblastoma uniquístico con patrón plexiforme: revisión de la literatura a propósito de un caso clínico / Unicystic ameloblastoma with a plexiform pattern: literature review regarding a clinical case

En 1827 el médico James William Cusack describió una lesión tumoral expansiva con características clínicas similares al ameloblastoma. Para el 2017 la Organización Mundial de la Salud lo clasificó como un tumor odontogénico benigno de origen epitelial. En la actualidad hemos aceptado la teoría de su etiología asociada con una mutación en el biomarcador BRAF-V600E, donde se presentan claras heterogeneidades extra/intratumorales en el metabolismo de la tumorogénesis; la mutación en BRAF genera cambios en la regulación de la odontogénesis, en conjunto con el gen CDC73 presente en el cromosoma 1 q25-q32, lo que produce un cambio en la proteína parafibromina que inhibe la proliferación celular durante el crecimiento y la división celular, esto afecta en conjunto al gen p53 y su homólogo p63 presentes en el cromosoma 17, por lo que se tiene como resultado la expresión de quistes y tumores dentales como el ameloblastoma. La presente obra muestra el caso clínico de un paciente femenino de 11 años de edad con aumento de volumen en la región submandibular izquierda de 7 × 4 cm, con seis años de evolución; de tal manera que fue diagnosticado con ameloblastoma uniquístico y tratado de forma conservadora mediante enucleación, posteriormente fue valorada anualmente hasta que la paciente cumplió los 18 años de edad (AU)

In 1827, physician James William Cusack described an expansive tumor lesion with clinical characteristics similar to ameloblastoma. For 2017, the World Health Organization classified it as a benign odontogenic tumor of epithelial origin. Currently, we have accepted the theory of its etiology associated with a mutation in the BRAF-V600E biomarker, where there are clear extra/intratumoral heterogeneities in the metabolism of tumorigenesis; the BRAF mutation generates changes in the regulation of odontogenesis, together with the CDC73 gene present on chromosome 1 q25-q32, producing a change in the parafibromin protein that inhibits cell proliferation during cell growth and division, which together it affects the p53 gene and its p63 homolog is present on chromosome 17, resulting in the expression of dental cysts and tumors such as ameloblastoma. This work provides the clinical case of an 11-year-old patient with an increase in volume in the left submandibular region of 7 × 4 cm of 6 years of evolution. Being diagnosed as a unicistic ameloblastoma and treated conservatively by enucleation, it is subsequently evaluated annually until the patient reaches 18 years of age (AU)

Unicystic Ameloblastoma ? A Case Series

Ameloblastoma is a benign, locally aggressive neoplasm that constitutes about 1–3% of the tumors of the jaw. Wide surgical excision with adequate safe margin is the most common treatment of choice. The study aimed to manage cases with unicystic ameloblastoma while preserving the continuity of the mandible (without resection). This article presents a series of cases ranging from 18 to 40 years old patients of both sexes with unicystic ameloblastoma, especially in the mandible showing more male predilection than female. All the cases presented in this article were treated by enucleation and curettage. None of the patients presented post?operative paresthesia. None of the cases went in for resection. Post?operative recovery was uneventful in all the patients. All the patients were followed up for a period of 3.5–5 years. None of the cases reported recurrence at the date of publication.

Immunohistochemistry in oral and maxillofacial pathology: The role and rational use of antibodies in the diagnosis of surgical lesions / Inmunohistoquímica en patología oral y maxilofacial: El rol y uso racional de anticuerpos en el diagnóstico de lesiones quirúrgicas

Background:Immunohistochemistry have had a huge impact on oral and maxillofacial pathology diagnosis. As a method it determines distribution and amount of certain cellular molecules via specific antigen-antibody reaction. Whereas in most cases a definitive diagnosis is achieved based on detailed hematoxylin and eosin cytomorphological analysis, along with clinical and radiological features, some challenging and equivocal neoplasms need to be further assessed with immunohistochemistry. Objective:This article reviews and updates immunohistochemistry technique fundamentals, its role and relevance in the diagnosis of common oral and maxillofacial lesions encountered in daily practice. Materials and methods: A literature review on the topic was carried out by searching pertinent and available papers on PubMed, ClinicalKey and Scielo platforms with no date restriction, up to 2022. Conclusion: Immunohistochemistry is an important tool that has been integrated into conventional histopathology and provides diagnostic assistance in the interpretation of common but equivocal neoplasms

Antecedentes: El uso de la inmunohistoquímica ha tenido un gran impacto en el diagnóstico de patología oral y maxilofacial. Como técnica, determina la distribución y la cantidad de ciertas moléculas celulares a través de una reacción antígeno-anticuerpo específica. Aunque en la mayoría de los casos se logra obtener un diagnóstico definitivo basado en el análisis cito morfológico con hematoxilina y eosina, junto con las características clínicas y radiológicas, algunas neoplasias microscópicamente equívocas deben evaluarsemás a fondo con inmunohistoquímica. Objetivo: Este artículo revisa los fundamentos básicos actuales de la técnica y su relevancia en el diagnóstico de algunas lesiones orales y maxilofaciales frecuentemente tratadas en la práctica clínica diaria. Materiales y Métodos: Se realizó una búsqueda y revisión de artículos científicos relacionados con el uso immunohistoquímica en patología oral y maxilofacial en PubMed, ClinicalKey y Scielo. Conclusión: La immunohistoquimica es una herramienta importante que ha sido integrada a la histopatología convencional y brinda asistencia diagnostica en la interpretación de neoplasias comunes pero equívocas

Application of computer-assisted navigation technology in the resection and reconstruction of mandibular ameloblastoma / 口腔医学

Objective@# Using computer-assisted navigation technology to guide the resection and reconstruction of mandibular ameloblastoma, evaluating its treatment effect.@*Methods @# Twelve patients were selected from the Affiliated Stomatological Hospital of Nanjing University from January 2017 to May 2022. All 12 patients accepted same surgery which included resection of mandibular ameloblastoma and reconstruction by fibula musculocutaneous flap. Among them, 6 cases were included in the navigation group; 6 cases were in the non-navigation group. Advantages and disadvantages of computer-assisted navigation technology in this operation were evaluated with these cases. @*Results@# The 12 operations were performed by the same operator. The average time for fixing the navigation bracket and performing navigation in the navigation group was about 15 minutes. Compared with the non-navigation group, the average operation time in the navigation group was shortened by about 10 minutes. In the navigation group, the mandible resection range matched the fibula musculocutaneous flap well, and the occlusal relationship recovered well. @*Conclusion @#Using the mandibular reference frame, under the guidance of computer-assisted navigation technology, the resection and reconstruction of mandibular ameloblastoma can be performed quickly and accurately.

Application of Deep Learning in Differential Diagnosis of Ameloblastoma and Odontogenic Keratocyst Based on Panoramic Radiographs / 中国医学科学院学报

Objective To evaluate the accuracy of different convolutional neural networks (CNN),representative deep learning models,in the differential diagnosis of ameloblastoma and odontogenic keratocyst,and subsequently compare the diagnosis results between models and oral radiologists. Methods A total of 1000 digital panoramic radiographs were retrospectively collected from the patients with ameloblastoma (500 radiographs) or odontogenic keratocyst (500 radiographs) in the Department of Oral and Maxillofacial Radiology,Peking University School of Stomatology.Eight CNN including ResNet (18,50,101),VGG (16,19),and EfficientNet (b1,b3,b5) were selected to distinguish ameloblastoma from odontogenic keratocyst.Transfer learning was employed to train 800 panoramic radiographs in the training set through 5-fold cross validation,and 200 panoramic radiographs in the test set were used for differential diagnosis.Chi square test was performed for comparing the performance among different CNN.Furthermore,7 oral radiologists (including 2 seniors and 5 juniors) made a diagnosis on the 200 panoramic radiographs in the test set,and the diagnosis results were compared between CNN and oral radiologists. Results The eight neural network models showed the diagnostic accuracy ranging from 82.50% to 87.50%,of which EfficientNet b1 had the highest accuracy of 87.50%.There was no significant difference in the diagnostic accuracy among the CNN models (P=0.998,P=0.905).The average diagnostic accuracy of oral radiologists was (70.30±5.48)%,and there was no statistical difference in the accuracy between senior and junior oral radiologists (P=0.883).The diagnostic accuracy of CNN models was higher than that of oral radiologists (P<0.001). Conclusion Deep learning CNN can realize accurate differential diagnosis between ameloblastoma and odontogenic keratocyst with panoramic radiographs,with higher diagnostic accuracy than oral radiologists.

Frequency of central odontogenic tumors: a retrospective study in an Iraqi population utilizing 2022 WHO head and neck tumors classification / Frequência de tumores odontogênicos centrais: um estudo retrospectivo em uma população iraquiana utilizando a classificação de tumores de cabeça e pescoço da OMS de 2022

Objectives: Odontogenic tumors occupy an important position among head and neck tumors. Although, rarely encountered in medical practice but they considered increasingly challenging lesions for the clinicians due to their overlapping clinical and histopathological features. This study was designed to determine the relative frequency of central odontogenic tumors in an Iraqi population by utilizing 2022 WHO tumor classification. Material and methods: Sixty cases of central odontogenic tumors from a total of 1869 case records were retrieved retrospectively from the file archive of the histopathology laboratory in Baghdad medical city from the period of 2016 to 2021. For each individual case, data regarding age, gender, location, and tumor type were collected and analyzed. Results: odontogenic tumors constituted 3.2% of the total cases analyzed mostly benign. The male to female ratio was 1/1. The age of the patients ranged from 11 to 75 years. Most cases were recorded in the third and fourth decades of life (n=31, 51.6%). The most common benign and malignant tumors were ameloblastoma and ameloblastic fibrosarcoma respectively. Most of these tumors located in the mandible (n= 45, 75%). The most common mandibular tumor was ameloblastoma followed by ameloblastic fibroma, and odontogenic myxoma. Regarding maxillary tumors, the predominant tumor was ameloblastoma followed by ameloblastic fibroma, ameloblastic fibrosarcoma, and clear cell odontogenic carcinoma. Conclusions: Odontogenic tumors in an Iraqi population occurred more commonly in the mandible and showed no sex predilection. Most cases were diagnosed in third and fourth decades of life and ameloblastoma was the most frequent odontogenic tumor. The relative frequency of malignant odontogenic tumors was 11.67% of all cases studied mostly ameloblastic fibrosarcoma. (AU)

Objetivos: Os tumores odontogênicos ocupam uma posição importante entre os tumores de cabeça e pescoço. Embora raramente encontrados na prática médica, eles consideram lesões cada vez mais desafiadoras para os clínicos devido às suas características clínicas e histopatológicas sobrepostas. Este estudo foi desenhado para determinar a frequência relativa de tumores odontogênicos centrais em uma população iraquiana, utilizando a classificação de tumor da OMS de 2022. Materiais e métodos: Sessenta casos de tumores odontogênicos centrais de um total de 1.869 registros de casos foram recuperados retrospectivamente do arquivo do laboratório de histopatologia na cidade médica de Bagdá no período de 2016 a 2021. Para cada caso individual, dados sobre idade, sexo , localização e tipo de tumor foram coletados e analisados. Resultados: os tumores odontogênicos constituíram 3,2% do total de casos analisados em sua maioria benignos. A proporção entre homens e mulheres era de 1/1. A idade dos pacientes variou de 11 a 75 anos. A maioria dos casos foi registrada na terceira e quarta décadas de vida (n=31, 51,6%). Os tumores benignos e malignos mais comuns foram ameloblastoma e fibrossarcoma ameloblástico, respectivamente. A maioria desses tumores localizava-se na mandíbula (n= 45, 75%). O tumor mandibular mais comum foi o ameloblastoma, seguido do fibroma ameloblástico e do mixoma odontogênico. Em relação aos tumores maxilares, o tumor predominante foi o ameloblastoma seguido de fibroma ameloblástico, fibrossarcoma ameloblástico e carcinoma odontogênico de células claras. Conclusões: Os tumores odontogênicos em uma população iraquiana ocorreram mais comumente na mandíbula e não mostraram predileção por sexo. A maioria dos casos foi diagnosticada na terceira e quarta décadas de vida, sendo o ameloblastoma o tumor odontogênico mais frequente. A frequência relativa de tumores odontogênicos malignos foi de 11,67% de todos os casos estudados principalmente fibrossarcoma ameloblástico (AU)

Ameloblastoma uniquístico de mandíbula / Unicystic ameloblastoma of the mandible

Introducción: los ameloblastomas son tumores epiteliales odontogénicos benignos, localmente invasivos que surgen de restos de la lámina dental y del epitelio odontogénico. Presentación del caso: paciente femenina de 39 años con aumento progresivo e indoloro en la región derecha de la cara y cuello. Se palpó tumoración bien circunscrita, indolora, de consistencia dura, no fluctuante de 5 cm de diámetro. La radiografía panorámica mostró una lesión radiolúcida unilocular cerca de la zona del primer molar izquierdo. La tomografía computarizada confirmó los hallazgos. La biopsia reveló una cavidad quística revestida por epitelio odontogénico fino. Se practicó resección total con mandibulectomía segmentaría. Discusión: el ameloblastoma es una lesión poco frecuente con características similares a los quistes maxilares. Los hallazgos histológicos e inmunohistoquímicos permiten diferenciarlo de otras lesiones benignas y malignas. Conclusión: es un tumor benigno de crecimiento lento y con alta capacidad de recidivas. La resección quirúrgica completa con bordes amplios es la medida terapéutica recomendada. El seguimiento a largo plazo es obligatorio debido al riesgo de recurrencia y transformación maligna.

Introduction: ameloblastomas are benign locally invasive epithelial odontogenic tumors arising from remnants of the dental lamina and odontogenic epithelium. Case presentation: a 39-year-old female patient presenting with progressive and painless swelling of the right side of the face and neck. A well-defined non-tender, firm, non-fluctuating tumor measuring 5 cm in diameter was identified upon palpation. A panoramic radiography showed an unilocular radiolucent lesion near the first right mandibular molar tooth. These findings were confirmed by computed tomography. The biopsy revealed a cyst cavity lined by fine odontogenic epithelium. Patient underwent a total segmental mandibulectomy. Discussion: ameloblastoma is a rare lesion with features of maxillary cysts. Histologic and immunohistochemical findings allow distinguishing ameloblastomas from other benign and malignant lesions. Conclusion: it is a benign slow-growing tumor with a high capacity for recurrence. The recommended therapeutic approach is complete surgical resection with a wide margin of normal tissue. Extended follow-up is advisable due to its high recurrence and malignant transformation potential.

Ameloblastoma metastásico / Metastatic ameloblastoma

77REPERT MED CIR. 2023;32(1):77-80Mario Alexander Melo MD*María Camila PiñerosbAna María TorresbFabián Parra F. MDcRafael Baracaldo A. MDda Patología. Grupo de Patología Oncológica, Instituto Nacional de Cancerología, Universidad El Bosque. Bogotá DC, Colombia. b Odontólogía, Patología Oral y Medios Diagnósticos, Universidad El Bosque, Bogotá DC, Colombia. c Radiología e Imágenes Diagnósticas, Fundación Universitaria Sanitas, Bogotá DC, Colombia. d Patología, Fundación Universitaria de Ciencias de la Salud. Bogotá DC, Colombia.Introducción: el ameloblastoma es un tumor epitelial benigno de origen odontogénico, de crecimiento progresivo, caracterizado por expansión ósea y tendencia a la recurrencia local si no se trata en forma adecuada. De acuerdo con las características clínicas y radiográficas se clasifica en ameloblastoma uniquístico, periférico/extraóseo y el metastásico. Presentación del caso: el presente manuscrito se quiere reseñar el caso clínico de un ameloblastoma metastásico, el cual es capaz de producir siembras a pesar de su apariencia histológica benigna. Discusión y conclusiones: las variadas formas clínicas y radiográficas hacen que el ameloblastoma metastásico requiera, desde su diagnóstico inicial, un estudio detallado ya que es importante entender el concepto de esta patología como lesión clínica que realiza metástasis a distancia, pero su comportamiento histológico es benigno

Introduction: ameloblastoma is a benign epithelial odontogenic tumor that progresses slowly and is characterized by bone expansion and tendency for local recurrence if not treated properly. According to the clinical and radiographic characteristics, it is classified as unicystic, peripheral/extraosseous and metastatic ameloblastoma. Case presentation: the present manuscript aims to review the clinical case of a metastatic ameloblastoma, which can metastasize in spite of a benign histological appearance. Discussion and conclusions: the various clinical and radiographic forms of metastatic ameloblastoma require, from its initial diagnosis, a detailed study, since it is important to understand the concept of this clinico-pathological entity as a lesion with distant metastases but benign histological features

Variability in the Epithelial Expression of Ki67 and Polarization Characteristics of Collagen in Odontogenic Cysts and Tumours

ABSTRACT Objective: To assess the proliferation of epithelium (using the Ki67 index) and the polarization pattern of collagen in selected odontogenic cysts and tumours. In addition, an exploratory analysis of the effect of inflammation on the proliferation rate was done. Material and Methods: Following immunohistochemical staining, the labelling/proliferation index of Ki67 was calculated. The thickness and corresponding polarization colour of 100 juxta-epithelial picrosirius red-stained collagen fibers were assessed using linear micrometry with an eyepiece reticule under × 1000 magnification. Inflammation was graded subjectively as mild, moderate, and severe. Results: Overall Ki-67 expression was higher in the radicular cyst, Odontogenic Keratocyst, Ameloblastoma, while suprabasal Ki-67 positivity was maximum in Odontogenic Keratocyst. The stromal collagen fibers in Ameloblastoma showed predominantly green birefringence, whereas Odontogenic Keratocyst had orange birefringence. There was no significant association of inflammation with Ki-67 expression or birefringence patterns. Conclusion: The highest Ki67 expression in the radicular cyst, followed by Odontogenic Keratocyst and Ameloblastoma. Differences in the collagen maturation pattern were noted innately in five lesions studied and were further influenced by inflammatory changes. Epithelial proliferation and concomitant expression of thickness and maturity of the stromal collagen are innate features of the lesion further influenced by inflammation in various odontogenic cysts and tumours and may, in turn, guide the clinical behavior.

Pattern of histologic variants of ameloblastoma in a secondary health care facility in Lagos state a 5-year retrospective study

Ameloblastoma is a benign epithelial odontogenic neoplasm which is common amongst the Yoruba ethinc group. The various histologic types have been elucidated. Aim: This study aimed to assess the prevalent histologic types of ameloblastoma in a Lagos secondary health care facility. Methodology: A 5-year retrospective review of histopathologically diagnosed slides were retrieved. Data extracted include the age, gender, location, ethnicity and histologic variants were analysed by SPSS version 26. Percentages, ratio, mean, standard deviation and crude odd ratio were determined, and p-value ⩽ 0.05 is considered significant. Result: A total of seventy-seven histopathologically diagnosed ameloblastoma slides were retrieved. Males were more affected than females in ratio 1.2:1 with the mean age 33.61±13.3. Ameloblastoma was commonest in the third decade of life and more in the mandible than maxilla. Yoruba ethnic group was most affected. The commonest histologic type was the unicystic type with intraluminal subtype accounting for the largest proportion. There was significant association between histologic types and gender (p= 0.037). Crude odd ratio revealed the odds in the unicystic type between male and female {p=0.041; CI=95%, OR=2.649(1.042-6.733)} and in the follicular between male and female {p=0.013; CI=95%, OR=3.855(1.321-11.288)}. Conclusion: The unicystic histologic type of ameloblastoma was the commonest, occurring more in females and this was followed by the follicular histologic type which occurred more in males in this Lagos State secondary health care facility.

Retrospective Analysis of Ameloblastoma: An Institutional Experience

Introduction: Neoplasms that are derived from odontogenic tissues represent an uncommon and heterogenous group of enti- ties in oral and maxillofacial region comprising about 1% of all jaw tumors. Ameloblastoma received particular attention of oral pathologists due to its local aggressive behavior. Objective: Indian studies, regarding prevalence of ameloblastoma are very few. The present study was done to analyze and compare clinical, radiographic and histopathologic features of 57 cases of ameloblastomas in India retrospectively. Materials and methods: 57 cases of histologically diagnosed ameloblastomas were retrieved from the archives over a five year period to analyze the age, sex, site, clinical presentation, radiographic features and histopathology. Results: In the present study, ameloblastoma accounted for 77% of all odontogenic tumors with a mean age of 37.5 years in males and 42 years in females. About 60% of the cases revealed mandible as most common site predominantly of posterior re- gion with common clinical presentation as painless swelling. Radiographically, multilocular radiolucency was noticed in about 54.3% of cases. Among the histological variants of solid/multicystic ameloblastomas, follicular variant was reported to be the most common (38%) and intraluminal variant (19%) to be the common subtype in unicystic ameloblastomas. Statistical analy- sis was done among the histological variants of ameloblastomas which showed no statistical significance (p<0.05). Conclusion: The findings in the present study were well in accordance with previous reported studies. However, extensive studies with larger samples need to be carried out in the Indian population to evaluate the incidence of ameloblastoma for more definitive results.

Immunohistochemical Evaluation of Calretinin in Ameloblastoma, Odontogenic keratocyst and Dentigerous Cyst

Background: Calretinin plays an important role in calcium signalling and naturally expressed in nervous tissues. Various stud- ies suggest that calretinin may involve in amelogenesis. Calretinin also seems to have role in tumorigenesis since it regulates apoptosis. Aim: To find out whether there is any variation in expression of calretinin in Ameloblastoma, Odontogenic keratocyst and Dentigerous cyst. Materials & Methods: A total of 50 samples each from Ameloblastoma, odontogenic keratocyst and Dentigerous cyst were retrospectively studied. The immunohistochemical expression of calretinin was assessed by using calretinin antibody. Results: Chi square test was used to compare categorical parameters between groups. Kruskal Wallis Test and Mann-Whitney U Test were carried out to compare quantitative parameters among the groups. Statistically, significant values were obtained when comparing the immunohistochemical expression of calretinin in various odontogenic lesions studied and it was highest in ameloblastoma followed by OKC. None of the cases of dentigerous cyst were immunopositive for calretinin. Conclusion: There was statistically significant variation in the expression of calretinin among ameloblastoma, OKC and dentig- erous cyst and it contributes to the aggressiveness of those lesions.

Granular cell ameloblastoma: A rare and unique variant

Ameloblastoma is a slow-growing and locally invasive epithelial odontogenic tumor of the jaw that runs a benign course in most cases. Granular cell ameloblastoma is a rare subtype of ameloblastoma, showing the granular transformation of its cytoplasm. It is considered as an aggressive variant of ameloblastoma. Herein, we report the case of a 34-year-old male patient who presented with a swelling in the left cheek for a 1-year duration with a recent rapid increase in size. Examination showed a 4 � 3 cm growth involving the left buccal mucosa and retromolar area. Imaging studies showed expansile lytic lesion mandible. Biopsy revealed neoplasm with odontogenic epithelial islands showing peripheral palisading of tall columnar cells with reversal of polarity and the center of the islands showing stellate reticulum-like cells which were markedly replaced by granular cells. Granular cells can appear in various odontogenic and non-odontogenic tumors. When there is extensive granular cell change in ameloblastoma, it should be differentiated from other oral lesions with granular cells including granular cell odontogenic tumor, granular cell tumor, and congenital epulis.

Effectiveness of Molecular?Targeted Chemotherapy in Ameloblastomas: A Systematic Review

Ameloblastoma is a benign, locally aggressive neoplasm that needs extensive surgical resection. The goal of this article is to obtain an in?depth review of benign ameloblastomas to determine the available level of evidence and the possible benefit of targeted therapeutics for the treatment of ameloblastoma and BRAF V600E mutation in ameloblastoma. An electronic literature search was conducted according to PRISMA guidelines in PubMed/MEDLINE, EBSCO, and Web of Science for eligible studies published between 1975 and 2021. The systematic review is registered with INPLASY (INPLASY202260018). The review included 2 case series and 17 case reports. The histopathological type, anatomic location, expression of BRAF mutation, additional mutations, and molecular?targeted therapies of the 19 reviewed articles were summarized and tabulated. Interestingly, the majority of the primary site of ameloblastoma was located in the mandible (80.9%) compared to the maxilla (17%). The tumour size was reported in nine of the included studies. Most of the included studies in the review exhibited ameloblastoma with BRAF V600E mutations and responded to molecular?targeted therapies. Molecular therapies employing BRAF and/or MEK inhibitors in ameloblastoma with BRAF V600E mutations proved to be an appropriate treatment based on the limited available evidence. It is essential further to deepen our understanding at th

Recorrência do ameloblastoma: análise de fatores clínicoradiográficos e imunoexpressão de hMSH2, hMLH1 e KI-67 / Ameloblastoma recurrence: analysis of clinical-radiographic factors and immunoexpression of hMSH2, hMLH1 and KI-67

Introdução: O ameloblastoma é uma neoplasia odontogênica benigna, que apresenta altas taxas de recorrência pós-operatória. Diversos estudos mostram a relação entre as características clínico-patológicas e as modalidades de tratamento na recorrência do ameloblastoma. Os mecanismos moleculares envolvidos com a etiopatogenia deste tumor são pouco conhecidos, e apesar de alterações no Sistema Mismatch favorecerem o desenvolvimento de diferentes neoplasias humanas, a importância destes no desenvolvimento do ameloblastoma ainda permanece pouco compreendido. Objetivo: Identificar os fatores clínico-patológicos associados à recorrência do ameloblastoma, bem como investigar o papel da imunoexpressão das proteínas hMLH1, hMSH2 e Ki-67 na recidiva desses tumores odontogênicos. Metodologia: Tratou-se de um estudo descritivo, transversal e restrospectivo, com uma amostra constituída por 22 casos de ameloblastomas recidivantes e 22 casos não-recidivantes. A análise imunoistoquímica foi realizada de forma quantitativa, considerando a localização celular (nuclear) das proteínas estudadas. O teste de McNemar foi utilizado para comparar as variáveis entre lesões da 1ª biópsia e recorrentes de AMB. A sobrevida livre de recorrência foi analisada pelo método de Kaplan-Meier e as funções de sobrevida foram comparadas de acordo com as variáveis pelo teste log-rank. Resultados: O gênero mais acometido foi o feminino (n=24; 54,5%), com média de idade de acometimento de 39,1 ± 19,8 anos, sendo 45,5% (n=20) leucodermas. A região posterior de mandíbula foi a mais frequente no grupo recidivante (n=18, 81,8%) e também para os casos que não apresentaram recidivas (n=16, 72,8%). O tempo livre de recorrência foi de 50,0 (34,5 ­ 63,6) meses. Foram fatores significativamente associadas à recorrência dos ameloblastomas: presença de expansão da cortical (p=0,0089), ausência de reconstrução óssea (p=0,018), tratamento conservador (p=0,021), perda de imunoexpressão de hMSH2 (p=0,006) e hMLH1 (p=0,038) e forte imunoexpressão de Ki-67 (p=0,029). Conclusão: Baseado nos achados desta pesquisa, aspecto radiográfico, modalidade do tratamento e imunoexpressão de proteínas do Sistema Mismatch e Ki-67 podem ser utilizados como indicadores para a recorrência em ameloblastomas (AU).

Introduction: Ameloblastoma is a benign odontogenic neoplasm, which has high rates of postoperative recurrence. Several studies show the relationship between clinicopathological characteristics and treatment modalities in ameloblastoma recurrence. The molecular mechanisms involved in the etiopathogenesis of this tumor are little known, and although changes in the Mismatch System favor the development of different human neoplasms, their importance in the development of ameloblastoma still remains poorly understood. Objective: To identify clinical and pathological factors associated with ameloblastoma recurrence, as well as to investigate the role of immunoexpression of hMLH1, hMSH2 and Ki-67 proteins in the recurrence of these odontogenic tumors. Methodology: This was a descriptive, cross-sectional and retrospective study, with a sample consisting of 22 cases of recurrent ameloblastoma and 22 non-recurrent cases. Immunohistochemical analysis was performed quantitatively, considering the cellular (nuclear) location of the studied proteins. McNemar's test was used to compare variables between 1st biopsy and recurrent AMB lesions. Recurrence-free survival was analyzed using the Kaplan-Meier method and survival functions were compared according to variables using the log-rank test. Results: The most affected gender was female (n=24; 54.5%), with a mean age of involvement of 39.1 ± 19.8 years, 45.5% (n=20) being white. The posterior region of the mandible was the most frequent in the relapsed group (n=18, 81.8%) and also for the cases that did not present recurrences (n=16, 72.8%). Recurrence-free time was 50.0 (34.5 ­ 63.6) months. Factors significantly associated with recurrence of AMBs were: presence of cortical expansion (p=0.0089), absence of bone reconstruction (p=0.018), conservative treatment (p=0.021), loss of hMSH2 immunoexpression (p=0.006) and hMLH1 (p=0.038) and strong Ki-67 immunoexpression (p=0.029). Conclusion: Based on the findings of this research, radiographic appearance, treatment modality and immunoexpression of proteins from the Mismatch System and Ki-67 can be used as indicators for recurrence in ameloblastomas (AU).