Diagnóstico y tratamiento conservador del queratoquiste odontogénico

Resumen El queratoquiste odontogénico es una entidad potencialmente agresiva y de alta recurrencia, con características clínicas y radiográficas no definidas claramente. Se presenta en cualquier etapa de la vida. El 70 a 80% se ubican en la mandíbula, comúnmente en la región de tercer molar y ángulo mandibular desde donde progresan hacia la rama y cuerpo. Son lesiones en general asintomáticas que pueden alcanzar dimensiones notables. A menudo se encuentran en el examen radiográfico de rutina. El objetivo del presente artículo es reportar el caso de una mujer de 40 años de edad, con un queratoquiste odontogénico paraqueratinizado, evaluando sus características clínicas, radiográficas e histopatológicas que llevaron a un manejo y tratamiento conservador oportuno y adecuado con resultados satisfactorios. Concluyendo que la minuciosa elaboración de la historia clínica basado en hallazgos clínicos, radiográficos e histopatológicos conduce a un diagnóstico correcto, que permite la elaboración de un plan de tratamiento adecuado.

Resumo O Queratocisto odontogênico potencialmente agressivo e de alta recorrência, com características clínicas e radiográficas não claramente definidas. Ocorre em qualquer estágio da vida. 70 a 80% estão localizados na mandíbula, geralmente na região do terceiro molar e no ângulo mandibular de onde progridem para o ramo e o corpo. São lesões geralmente assintomáticas que podem atingir dimensões notáveis. Eles são freqüentemente encontrados no exame radiográfico de rotina. O objetivo deste artigo é relatar o caso de uma mulher de 40 anos com um queratocisto odontogênico paraqueratinizado, avaliando suas características clínicas, radiográficas e histopatológicas que conducem ao manejo e tratamento conservador oportuno e adequado, com resultados satisfatórios. Concluindo que o cuidadoso preparo da história médica com base em achados clínicos, radiográficos e histopatológicos leva a um diagnóstico correto, o que permite o desenvolvimento de um plano de tratamento adequado.

Abstract Odontogenic keratocysts are potentially aggressive and have high recurrence rates. Their clinical and radiographic features are not clearly defined. They can occur at any stage of life. Seventy to 80% are located in the mandible, commonly in the area between the third molar and the mandibular angle, from where they grow towards the ramus and body. They are generally asymptomatic lesions that can grow considerably. They are often found on routine radiographs. This paper reports the case of a 40-year-old woman with a parakeratinized odontogenic keratocyst. After assessing the cyst's clinical, radiographic and histopathological features, we managed and treated the condition timely, conservatively, and with satisfactory results. We concluded that preparing the patient's dental history carefully and based on clinical, radiographic, and histopathological findings allowed us to make the correct diagnosis and develop the necessary treatment plan.

The presentation of odontogenic keratocysts in the jaws with an emphasis on the tooth-bearing area: a systematic review and meta-analysis.

PURPOSE: This study was conducted in order to gain insight in the actual ratio of odontogenic keratocysts occurring in the tooth-bearing area as compared to the posterior region of the jaws in order to come up with reliable data to base upon a rational treatment policy. METHODS: We searched MEDLINE, Web of Science, Scopus, and Cochrane databases for studies reporting on the location of mandibular and maxillary odontogenic keratocysts. All records were independently assessed and a meta-analysis was performed. Risk difference with a confidence interval of 95% of having the lesion in the posterior region versus the tooth-bearing area was the effect measure. P value for the summary effect of < 0.05 was considered statistically significant. RESULTS: The 2615 records retrieved were reduced to 34 studies to be qualitatively/quantitatively assessed. The pooled values showed that the difference in the clinical risk of having keratocysts in the posterior region of the mandible and in the tooth-bearing area of the maxilla is 21 and 43%, respectively (P < 0.02 and P < 0.00001). CONCLUSIONS: A substantial amount of keratocysts occur in the tooth-bearing area of the jaws, requiring attention.

Tumor odontogénico queratoquístico en seno maxilar: reporte de un caso clínico / Keratocystic odontogenic tumor in the maxillary sinus: report of a clinical case

El tumor odontogénico queratoquístico, es una patología que se encuentra asociada a la retención de un órgano dentario, en especial al tercer molar, es reconocido por su potencial destructivo y extenso, erosionando placas corticales que envuelven mucosa y tejidos blandos, la etiología del tumor odontogénico queratoquístico está probablemente relacionada con el desarrollo de la lámina dental (o restos de Serres) y con una mayor recidiva dentro de los tumores odontogénicos, siendo motivo de su reclasificación en el 2005 por la OMS. Se presenta casoclínico de un tumor odontogénico queratoquístico en el seno maxilarderecho, se exponen los métodos utilizados para la exploración clínica,radiológica y el tratamiento quirúrgico elegido.

The keratocystic odontogenic tumor is a condition associated withtooth retention, particularly of the third molar. It is recognized as beingpotentially highly destructive, by eroding cortical plates overlying theoral mucosa and soft tissues. The etiology of keratocystic odontogenictumor is probably related to the development of the dental lamina (orremains of Serres) and the recurrence rate is high compared to that ofother odontogenic tumors, the reason for their reclassifi cation by theWHO in 2005. We present a clinical case of a keratocystic odontogenictumor in the right maxillary sinus, including an explanation of themethods used for clinical and radiological examination, and the chosensurgical treatment.

Glypican-3 distinguishes aggressive from non-aggressive odontogenic tumors: a preliminary study.

BACKGROUND: Glypican-3 is a cell surface proteoglycan that is found in embrionary tissues, and there are no studies investigating this protein in odontogenic tumor. Thus, the aim of this study was to investigate glypican-3 in a series of aggressive and non-aggressive odontogenic tumors. METHODS: Fifty-nine cases of tumors were divided into aggressive odontogenic tumors (20 solid ameloblastomas, four unicystic ameloblastoma, 28 KOTs including five associated with Gorlin-Goltz syndrome) and non-aggressive odontogenic tumors (five adenomatoid odontogenic tumors and two calcifying cystic odontogenic tumors) and analyzed for glypican-3 using immunohistochemistry. RESULTS: Glypican-3 was observed in seven solid ameloblastoma and eighteen keratocystic odontogenic tumors including three of the five syndromic cases, but there was no significant difference between syndromic and sporadic cases (P > 0.05; Fisher's exact Test). All cases of unicystic ameloblastoma (n = 4), adenomatoid odontogenic tumor (n = 5), and calcifying cystic odontogenic tumor (n = 2) were negative. CONCLUSIONS: This provided insights into the presence of glypican-3 in odontogenic tumors. This protein distinguished aggressive from non-aggressive odontogenic tumors.

Immunohistochemical analysis of myofibroblasts, TGF-ß1, and IFN-γ in epithelial odontogenic lesions.

AIM: To investigate the presence of myofibroblasts (MFBs) in epithelial odontogenic lesions by immunohistochemistry and to correlate the findings with tumor aggressiveness, as well as to analyze the expression of TGF-ß1 and IFN-γ during the differentiation of these cells. METHODS AND RESULTS: Twenty solid ameloblastomas (SAs), 10 unicystic ameloblastomas (UAs), 20 keratocystic odontogenic tumors (KCOTs), and 20 adenomatoid odontogenic tumors (AOTs) were selected. For evaluation of the presence of MFBs, anti-α-SMA-immunoreactive cells were quantified in connective tissue near the epithelium. The expression of TGF-ß1 and IFN-γ was evaluated in epithelial and connective tissue by determining the percentage of immunoreactive cells. A higher concentration of MFBs was observed in SAs (mean of 30.55), followed by KCOTs (22.50), UAs (20.80), and AOTs (19.15) (P = 0.001). There was no significant correlation between the immunoexpression of TGF-ß1 or IFN-γ and the number of MFBs (P > 0.05). CONCLUSIONS: The larger number of MFBs suggests that these cells are one of the factors responsible for the more aggressive biological behavior of these lesions. The lack of correlation between the number of MFBs and immunoexpression of TGF-ß1 and IFN-γ indicates that these proteins are not involved in the differentiation of this type of contractile cell in the lesions studied and that only the use of immunohistochemistry to establish such a correlation is a limiting factor.

Bioinformatics Analysis Reveals Genes Involved in the Pathogenesis of Ameloblastoma and Keratocystic Odontogenic Tumor.

Pathogenesis of odontogenic tumors is not well known. It is important to identify genetic deregulations and molecular alterations. This study aimed to investigate, through bioinformatic analysis, the possible genes involved in the pathogenesis of ameloblastoma (AM) and keratocystic odontogenic tumor (KCOT). Genes involved in the pathogenesis of AM and KCOT were identified in GeneCards. Gene list was expanded, and the gene interactions network was mapped using the STRING software. "Weighted number of links" (WNL) was calculated to identify "leader genes" (highest WNL). Genes were ranked by K-means method and Kruskal-Wallis test was used (P<0.001). Total interactions score (TIS) was also calculated using all interaction data generated by the STRING database, in order to achieve global connectivity for each gene. The topological and ontological analyses were performed using Cytoscape software and BinGO plugin. Literature review data was used to corroborate the bioinformatics data. CDK1 was identified as leader gene for AM. In KCOT group, results show PCNA and TP53. Both tumors exhibit a power law behavior. Our topological analysis suggested leader genes possibly important in the pathogenesis of AM and KCOT, by clustering coefficient calculated for both odontogenic tumors (0.028 for AM, zero for KCOT). The results obtained in the scatter diagram suggest an important relationship of these genes with the molecular processes involved in AM and KCOT. Ontological analysis for both AM and KCOT demonstrated different mechanisms. Bioinformatics analyzes were confirmed through literature review. These results may suggest the involvement of promising genes for a better understanding of the pathogenesis of AM and KCOT.

Influência de parâmetros clínicos, radiográficos, cirúrgicos e histopatológicos na taxa de recidiva dos ceratocistos odontogênicos: uma análise retrospectiva de coorte / Influence of clinical-radiographic, surgical and histopathological parameters in recurrence rate of Odontogenic Keratocysts: a retrospective cohort analysis

Não existe, na literatura, um consenso sobre o protocolo ideal de tratamento do Ceratocisto Odontogênico (CO). Isso se deve a alguns fatores, dentre eles à falta de padronização adequada dos dados avaliados nos trabalhos científicos. Essa falha é, muitas vezes, inerente a estudos retrospectivos. O objetivo deste estudo é avaliar a influência de parâmetros clínicos, radiográficos, cirúrgicos e histopatológicos no índice de recidiva do CO. Como diferencial, foram selecionados casos tratados de maneira uniforme e detalhada, pelo mesmo cirurgião. O tratamento foi a enucleação associada à ostectomia periférica, precedida ou não por descompressão da lesão. A amostra (n=24) foi composta por pacientes, com uma média de idade de 32.1 anos, que se apresentaram para tratamento inicial de uma lesão única de CO. Quatorze lesões (58.4%) foram submetidas a descompressão prévia. O tempo médio de acompanhamento dos pacientes foi de 60.5 meses (DP=31.3). Oito indivíduos (33%) apresentaram recidiva dos Cos e o tempo médio para desenvolvimento da recidiva foi de 19 meses (DP=4.9). Todas as recidivas foram diagnosticadas nos dois primeiros anos de acompanhamento e estavam significativamente associadas com: 1) pobre resposta clínica à descompressão (p=0.027); 2) preservação de dentes com evidência radiográfica de envolvimento de lesão entre as raízes dentárias (p=0.009) e 3) presença de brotamento epitelial da camada basal com ou sem formação de ilhas epiteliais na cápsula fibrosa (p=0.019). Este estudo sugere que parâmetros clínicos, radiográficos e microscópicos podem influenciar a recidiva do CO e têm a possibilidade ser avaliados individualmente como guia terapêutico

There is no consensus, in the literature, regarding the best protocol of treatment of Odontogenic Keratocyst (OKC). This is due to several factors, including the lack of adequate standardization of data assessed in the studies. This failure is usually inherent to retrospective studies. The objective of this study is to evaluate the influence of clinical, radiographic, surgical and microscopic parameters in the relapse rate of the disease. The differential aspect is in the uniform and detailed treatment applied by the same surgeon in all cases. The treatment applied was the enucleation with peripheral ostectomy, preceded by lesion decompression or not. The sample (n=24) was composed of patients, with a mean age of 32.1 years, presenting for the management of one untreated OKCs. Fourteen lesions (58.4%) were submitted to previous decompression procedure. The mean follow-up time was 60.5 months (SD=31.3). Eight patients (33%) developed recurrent lesions and a mean of disease-free interval for recurrent lesions of 19 months (SD=4.9). All recurrence lesions were diagnosed in two first years of follow-up and were significantly associated with: 1) poor clinical response to decompression (P=0.027); 2) remaining tooth with radiographic evidence of insinuation of the lesion between the dental roots (P=0.009); 3) presence of budding of the basal cells layer together with epithelial islands in the fibrous capsule (P=0.019). Our study suggests that these clinical, radiographic and microscopic parameters could affect relapse rate of patients with OKC and may individually guide the treatment choice

Keratocystic odontogenic tumor: clinicopathological aspects and treatment / Tumor odontogénico queratoquístico: aspectos clínico-patológicos y tratamiento

The keratocystic odontogenic tumor is a benign intraosseous neoplasm derived from remnants of the dental lamina and it occurs with high frequency. Regarding histological characteristics, it has a high recurrence rate which is one of the main therapeutic problems. Also, it presents high local aggressiveness, expressed in cortical expansion, delayed eruption and displacement of teeth, blood vessels and nerves. At present, there are various treatments, being ideal the one which presents the lowest risk of recurrence with low morbidity for the patient. In this review, the main histopathological, clinical and therapeutic aspects of this oral pathology are discussed.

El tumor odontogénico queratoquístico es una neoplasia intraósea benigna que deriva de restos de la lámina dental, y que se presenta con alta frecuencia. Sus características histológicas le confieren una elevada tasa de recidiva, siendo este uno de sus principales problemas terapéuticos. Presenta además una considerable agresividad local, la cual se expresa con la expansión de corticales óseas, retardo en la erupción y desplazamiento de dientes, vasos sanguíneos y nervios. En la actualidad existen diversos tratamientos, siendo el ideal aquel que presente el menor riesgo de recidiva con una baja morbilidad para el paciente. En la presente revisión se discuten los principales aspectos histopatológicos, clínicos y terapéuticos de esta patología oral.

Transcriptional profiles of SHH pathway genes in keratocystic odontogenic tumor and ameloblastoma.

BACKGROUND: Sonic hedgehog (SHH) pathway activation has been identified as a key factor in the development of many types of tumors, including odontogenic tumors. Our study examined the expression of genes in the SHH pathway to characterize their roles in the pathogenesis of keratocystic odontogenic tumors (KOT) and ameloblastomas (AB). METHODS: We quantified the expression of SHH, SMO, PTCH1, SUFU, GLI1, CCND1, and BCL2 genes by qPCR in a total of 23 KOT, 11 AB, and three non-neoplastic oral mucosa (NNM). We also measured the expression of proteins related to this pathway (CCND1 and BCL2) by immunohistochemistry. RESULTS: We observed overexpression of SMO, PTCH1, GLI1, and CCND1 genes in both KOT (23/23) and AB (11/11). However, we did not detect expression of the SHH gene in 21/23 KOT and 10/11 AB tumors. Low levels of the SUFU gene were expressed in KOT (P = 0.0199) and AB (P = 0.0127) relative to the NNM. Recurrent KOT exhibited high levels of SMO (P = 0.035), PTCH1 (P = 0.048), CCND1 (P = 0.048), and BCL2 (P = 0.045) transcripts. Using immunolabeling of CCND1, we observed no statistical difference between primary and recurrent KOT (P = 0.8815), sporadic and NBCCS-KOT (P = 0.7688), and unicystic and solid AB (P = 0.7521). CONCLUSIONS: Overexpression of upstream (PTCH1 and SMO) and downstream (GLI1, CCND1 and BCL2) genes in the SHH pathway leads to the constitutive activation of this pathway in KOT and AB and may suggest a mechanism for the development of these types of tumors.

Tumor odontogénico queratoquístico: revisión de la literatura a propósito de un caso clínico / Keratocystic odontogenic tumor: a review of the literature in reference to a clinical case

El Tumor odontogénico queratoquístico es una entidad benigna de prevalencia relativamente alta que surge desde los remanentes de la lámina dental, el cual tiene un potencial comportamiento agresivo y alta recurrencia. Este tiende a crecer lentamente dentro del canal medular en sentido anteroposterior transformándose en una gran lesión sin causar una expansión obvia. Esta revisión describe la clínica, imagenología y tratamientos actuales del Tumor Odontogénico Queratoquístico a propósito de un paciente de sexo masculino 30 años diagnosticado con esta entidad.

Keratocystic Odontogenic tumor is a benign entity with relatively high prevalence that arises from remains of dental lamina. It has a potentially aggressive behaviour, high recurrence and anteroposterior slow growth in the medullar canal, which can become large lesion without obvious expansion. This review describes clinical, imagenological and current treatments of Keratocystic Odontogenic Tumor in 30- year-old male patient diagnosed with this entity.

Reemplazo articular temporomandibular debido a queratoquiste odontogénico / Temporomandibular joint replacement because of odontogenic keratocyst

Existen disímiles condiciones que hacen necesario el reemplazo articular temporomandibular; dentro de las más frecuentes se encuentran la anquilosis, la osteoatrosis, estadíos avanzados del Síndrome de disfunción temporomandibular, daño articular postrauma y procesos neoplásicos o tumorales. Los queratoquistes odontógenos que se agrupan para su estudio dentro de los quistes odontogénicos del desarrollo, representan cerca del 7 al 10 por ciento de todos los quistes maxilo-mandibulares. Se dice que tienen dos picos de incidencia entre la segunda y tercera década de vida y entre los 50 y 60 años de edad, con una ligera predilección por el sexo masculino. Aparece más frecuentemente en la región del tercer molar de la mandíbula con extensión a la rama ascendente El presente trabajo tuvo como objetivo mostrar el caso de un paciente masculino de 57 años de edad en el que fue necesario el reemplazo articular temporomandibular debido a un queratoquiste odontogénico que involucraba la totalidad de la rama mandibular derecha, incluyendo el proceso condíleo y coronoideo, así como el ángulo hasta el tercio posterior del cuerpo mandibular. Tras un año de realizada la intervención quirúrgica la evolución del paciente fue satisfactoria(AU)

Temporomandibular joint replacement is required in a variety of conditions. Among the most frequent are ankylosis, osteoarthrosis, advanced stages of the temporomandibular dysfunction syndrome, post-traumatic joint damage, and neoplastic or tumoral processes. Odontogenic keratocysts, which are classified as developmental odontogenic cysts for study purposes, constitute 7-10 per cent of all maxillomandibular cysts. Two peaks have been identified in their incidence: between the second and third decades of life, and between 50 and 60 years of age, with a slight predominance of the male sex. They are most common in the third molar area of the mandibule, with expansion to the ascending branch. A case is presented of a male 57-year-old patient requiring temporomandibular joint replacement due to an odontogenic keratocyst involving the entire right mandibular branch, including the condylar and coronoid processes, as well as the angle as far as the posterior third of the mandibular body. One year after surgery, the patient's evolution was satisfactory(AU)

Reemplazo articular temporomandibular debido a queratoquiste odontogénico / Temporomandibular joint replacement because of odontogenic keratocyst

Existen disímiles condiciones que hacen necesario el reemplazo articular temporomandibular; dentro de las más frecuentes se encuentran la anquilosis, la osteoatrosis, estadíos avanzados del Síndrome de disfunción temporomandibular, daño articular postrauma y procesos neoplásicos o tumorales. Los queratoquistes odontógenos que se agrupan para su estudio dentro de los quistes odontogénicos del desarrollo, representan cerca del 7 al 10 por ciento de todos los quistes maxilo-mandibulares. Se dice que tienen dos picos de incidencia entre la segunda y tercera década de vida y entre los 50 y 60 años de edad, con una ligera predilección por el sexo masculino. Aparece más frecuentemente en la región del tercer molar de la mandíbula con extensión a la rama ascendente El presente trabajo tuvo como objetivo mostrar el caso de un paciente masculino de 57 años de edad en el que fue necesario el reemplazo articular temporomandibular debido a un queratoquiste odontogénico que involucraba la totalidad de la rama mandibular derecha, incluyendo el proceso condíleo y coronoideo, así como el ángulo hasta el tercio posterior del cuerpo mandibular. Tras un año de realizada la intervención quirúrgica la evolución del paciente fue satisfactoria(AU)

Temporomandibular joint replacement is required in a variety of conditions. Among the most frequent are ankylosis, osteoarthrosis, advanced stages of the temporomandibular dysfunction syndrome, post-traumatic joint damage, and neoplastic or tumoral processes. Odontogenic keratocysts, which are classified as developmental odontogenic cysts for study purposes, constitute 7-10 per cent of all maxillomandibular cysts. Two peaks have been identified in their incidence: between the second and third decades of life, and between 50 and 60 years of age, with a slight predominance of the male sex. They are most common in the third molar area of the mandibule, with expansion to the ascending branch. A case is presented of a male 57-year-old patient requiring temporomandibular joint replacement due to an odontogenic keratocyst involving the entire right mandibular branch, including the condylar and coronoid processes, as well as the angle as far as the posterior third of the mandibular body. One year after surgery, the patient's evolution was satisfactory(AU)

Odontogenic keratocyst tumor: report of two cases / Tumor queratoquiste odontogénico: reporte de dos casos

In 2005, odontogenic cyst was classified as keratocyst odontogenic tumor due to being aggressive and recurrent. The keratocyst odontogenic tumor has characteristics, with slow development, does not cause metastases and provides great bone destruction. The aim of this study was to discuss the aspects regarding the diagnosis, prognosis and treatment of odontogenic keratocyst tumor, through the report of two cases. Both initially underwent decompression of the lesion present proximity of anatomical structures to be great and noble, aiming to prevent pathological fractures. We carried out the clinical-radiographic and after regression of the lesion, patients underwent enucleation total.

El año 2005 quiste odontogénico fue clasificado como un tumor queratoquiste odontogénico (TQO) debido a su agresividad y recurrencia. El TQO tiene las características del tumor: crecimiento lento, no causa metástasis y proporciona una gran destrucción ósea. El objetivo de este estudio fue examinar los aspectos relacionados con el diagnóstico, pronóstico y tratamiento del TQO mediante la presentación de dos casos. Ambos casos fueron inicialmente sometidos a descompresión debido al gran tamaño de la lesión y la proximidad de ésta con estructuras anatómicas importantes, con el objetivo de prevenir las fracturas patológicas. Se llevó a cabo un seguimiento clínico-radiográfico y después de tener una regresión de la lesión postdescompresión, los pacientes fueron sometidos la enucleación total.

Tumor odontogênico ceratocístico: levantamento de casos e revisão de literatura / Keratocystic odontogenic tumor: survey of cases and literature review

Introdução: O Tumor Odontogênico Ceratocístico (TOC) pode ser definido como um tumor intraósseo, benigno, de origem odontogênica. A incidência dessa lesão na mandibula é de 3 a 4 vezes maior que na maxila, com preferência pela região dos terceiros molares inferiores, no ângulo da madíbula, de onde se estende para o ramo ascentende. Em casos de lesões mais extensas, observa-se tumefação, drenagem ou dor associada, aumento de volume de tecidos moles e tecido ósseo, parestesia, mobilidade de dentes envolvidos pela lesão, bem como crescimento lento e deslocamento de peças dentárias. Objetivo e Metodologia: O objetivo deste trabalho foi realizar uma revisão da literatura e um levantamento de casos diagnosticados no Laboratóro de Patologia do Instituto de Ciências Biológicas da UPF a respeito do TOC. Resultados: No presente levantamento, foram encontrados 48 casos de TOC, com uma prevalencia do gênero feminino, na segunda e terceira década de vida. Um maior número de casos ocorreram na mandibula com preferencia pela região de terceiro molar inferior. Apresentavam em sua maioria lesões radiolúcidas uniloculares e o principal sinal clínico foi o de abaulamento. Conclusão: O que pode-se concluir através deste trabalho é que é fundamental para o sucesso do tratamento do Tumor Odontogênico Ceratocístico, o conhecimento por parte do Cirurgião Dentista de lesões tumorais de origem odontogênica , para que um correto e precoce diagnóstico seja executado, levando a melhor escolha do tratamento e, consequentemente um prognóstico favorável.

Introduction: The Keratocystic odontogenic tumor can be defined like an intraosseous tumor, benign, of odontogenic origin. The incidence of this lesion in the mandible and 3 to 4 times higher than in the maxilla, with a preference for the third molar region. In cases of more extensive lesions, there is swelling, drainage or pain associated, swelling of soft tissue and bone tissue, paresthesia, mobility of teeth involved by the injury, as well as slow growth and displacement of dental pieces. Objective and Methodology: The objective of this study was a literature review and a survey of cases diagnosed in the Pathology Lab of the Institute of Biological Sciences, UPF, about keratocystic odontogenic tumor. Result: In this survey, we found 48 cases of TOC, with a prevalence of females in second and third decade of life. A greater number of cases occurred in the jaw with a preference for the third molar region. Had mostly unilocular radiolucent lesions and was the main clinical sign of bulging. Conclusion: What can be concluded from this work is that it is essential for the successful treatment of odontogenic tumor keratocystic, knowledge by the Surgeon Dentist of odontogenic origin tumors, for a correct and early diagnosis is performed, taking the best choice of treatment and thus a favorable prognosis.

Particularidades do diagnóstico e tratamento do tumor odontogênico queratocístico / Diagnostic and treatment features of keratocystic odontogenic tumors

Keratocystic odontogenic tumors (KCOT) comprise a unique pathological entity characterized by aggressive/destructive behavior and propensity to recurrence. This study describes the diagnostic and treatment features of a KCOT lesion. A 22-year old man was referred for surgical treatment of pericoronitis on tooth no. 37. Panoramic radiography revealed a unilocular, large radiolucent area extending from tooth no. 36 to the left mandibular ramus. Aspiration and incisional biopsy were performed, and the tissue sample was sent for microscopic evaluation. Microscopically, a cystic lesion was observed, lined by keratinized squamous epithelium and filled with keratin lamellae, confirming the diagnosis of KCOT. Surgery was performed in an outpatient setting and involved osteotomy, detachment of the cystic lesion, and removal of teeth no. 36, 37, and 38. The patient was clinically and radiographically followed for 12 months, and no evidence of recurrence was observed. KCOTs should be considered in the differential diagnosis of lesions affecting the posterior region of the mandible. Accurate clinical, radiographic, and microscopic examinations are essential to establish the definitive diagnosis and choose the most effective therapy.

O tumor odontogênico queratocístico (TOQ) é uma entidade patológica singular, devido ao seu comportamento agressivo/destrutivo e à sua propensão a recorrências. O presente trabalho descreve as particularidades de diagnóstico e tratamento de um TOQ. Um paciente do sexo masculino, com 22 anos de idade, foi encaminhado para tratamento cirúrgico de pericoronarite no dente 37. O exame radiográfico panorâmico revelou uma área ampla, unilocular, estendendo-se do dente 36 até o ramo esquerdo da mandíbula. Punção óssea aspirativa e biópsia incisional foram realizadas, e a amostra de tecido foi encaminhada para análise microscópica. Microscopicamente, observou-se lesão cística, revestida por epitélio escamoso queratinizado e preenchida por lamelas de queratina, confirmando o diagnóstico de TOQ. O procedimento cirúrgico foi realizado em ambiente ambulatorial e envolveu osteotomia, descolamento da luz da lesão e exodontia dos dentes 36, 37 e 38. O paciente foi acompanhado clínica e radiograficamente por um período de 12 meses, e não foi observada recorrência da lesão. O TOQ deve ser considerado no diagnóstico diferencial de alterações da região posterior da mandíbula. Exames clínicos, radiográficos e microscópicos precisos são essenciais no estabelecimento do diagnóstico e na escolha da modalidade terapêutica mais eficaz.

Immunohistochemical expression of p63, epidermal growth factor receptor (EGFR) and notch-1 in radicular cysts, dentigerous cysts and keratocystic odontogenic tumors

The aim of this study was to assess the immunohistochemical expression of p63 protein, epidermal growth factor receptor (EGFR) and Notch-1 in the epithelial lining of radicular cysts (RC), dentigerous cysts (DC) and keratocystic odontogenic tumors (KOT). For this study, 35 RC, 22 DC and 17 KOT were used. The clinical and epidemiological data were collected from the patient charts filed in the Oral Pathology Laboratory, University of Ribeirão Preto, Brazil. Immunohistochemical reactions against the p63, EGFR and Notch-1 were performed in 3-µm-thick histological sections. The slides were evaluated according to the following criteria: negative: <5% of positive cells, low expression: 5-50% of positive cells, and high expression: >50% of positive cells. Moreover, the intensity of EGFR and Notch-1 expressions was also evaluated. Fisher's exact test and Spearman's correlation coefficients were used for statistical analysis, considering a significance level of 5%. Almost all cases demonstrated p63, EGFR and Notch-1 expressions. The p63 expression was significantly higher in KOT (p<0.001). Positive correlation between these immunomarkers was observed. These findings suggest the participation of p63, EGFR and Notch-1 in the development, maintenance and integrity of cystic odontogenic epithelial lining, favoring lesion persistence. The high expression of p63 in KOT suggests that it may be related to their more aggressive biological behavior and marked tendency to recurrence.

O objetivo deste estudo foi avaliar a expressão imunoistoquímica da proteína p63, receptor do fator de crescimento epidérmico (EGFR) e Notch-1 no revestimento epitelial de cistos radiculares (CR), cistos dentígeros (CD) e tumores odontogênicos queratocísticos (TOQ). Para este estudo, 35 CR, 22 CD e 17 TOQ foram utilizados. Os dados clínicos e epidemiológicos foram coletados das fichas dos pacientes arquivadas no Laboratório de Patologia Oral, Universidade de Ribeirão Preto, Brasil. Reações imunoistoquímicas contra p63, EGFR e Notch-1 foram realizadas em cortes histológicos de 3 µm. As lâminas foram avaliadas de acordo com os seguintes critérios: negativo <5% das células positivas, baixa expressão - 5%-50% das células positivas e alta expressão >50% das células positivas. Além disso, a intensidade de expressão de EGFR e Notch-1 foi também avaliada. Teste exato de Fisher e coeficiente de correlação de Spearman foram usados para análise estatística, considerando um nível de significância de 5%. Quase todos os casos demonstraram expressão de p63, EGFR e Notch-1. A expressão de p63 foi significativamente maior nos TOQ (p<0.001). Correlação positiva entre os imunomarcadores foi observada. Esses achados sugerem a participação de p63, EGFR e Notch-1 no desenvolvimento, manutenção e integridade do revestimento epitelial cístico, favorecendo a persistência das lesões. A alta expressão de p63 no TOQ sugere que ela pode estar relacionada ao comportamento biológico mais agressivo e marcada tendência a recorrência.

Odontogenic keratocystic tumor: a clinical and histopathologic retrospective study based on the New WHO classification / Tumor odontogénico queratoquístico: estudio clínico e histopatológico retrospectivo basado en la nueva clasificación de la OMS

The aim was to review previous cases of Odontogenic Keratocyst or Keratocystic Odontogenic Tumor according to the new WHO classification. We used all cases diagnosed as Odontogenic Keratocyst or Keratocystic Odontogenic Tumor registered in the archives of the Pathologic Anatomy Laboratory of the Department of Pathology and Oral Diagnosis of the School of Dentistry of the Federal University of Rio de Janeiro, Rio de Janeiro, Brazil, which were collected from September, 1983 until September, 2008. The terms “Keratocyst” or “Keratocystic Odontogenic Tumor” were searched for and the following data were collected from the case files: age, sex, location of the lesion(s), and patients’ chief complaints. Hematoxilin and Eosin slides were reviewed according to the 2005 WHO criteria. The results found are in accordance with the literature. Due to its benign features, the Orthokeratinized Odontogenic Keratocyst found in our sample had its diagnosis changed to Orthokeratinized Odontogenic Cyst, as recommended by the WHO. Histopathologic exams are required for every bone lesion, in order to establish correct diagnosis. Because of its features, the Keratocystic Odontogenic Tumor must have more aggressive treatment, compared with odontogenic cysts, and long-term follow-up is mandatory.

El objetivo fue revisar los casos anteriores de queratoquiste odontogénico (QO) o tumor odontogénico queratoquístico (TOQ) de acuerdo con la nueva clasificación de la OMS. Fueron utilizados todos los casos diagnosticados como QO o TOQ registrados en los archivos del Laboratorio de Anatomía Patológica del Departamento de Patología y Diagnóstico Oral de la Facultad de Odontología de la Universidad Federal de Río de Janeiro, Rio de Janeiro, Brasil, registrados a partir de septiembre de 1983 hasta septiembre del 2008. Los términos "Queratoquiste" o "tumor queratoquistes odontogénicos" se buscaron y los siguientes datos se obtuvieron de los archivos del caso: edad, sexo, localización de la lesión (es), y quejas de los pacientes. Las muestras histológicas de hematoxilina y eosina fueron revisadas de acuerdo a los criterios de la OMS 2005. Los resultados encontrados estaban de acuerdo con la literatura. Debido a sus características benignas, el queratoquiste odontogénico ortoqueratinizado encontrado en nuestra muestra había cambiado su diagnóstico de quiste odontogénico ortoqueratinizado, según lo recomendado por la OMS. Los exámenes histopatológicos son necesarios para toda lesión ósea, con el fin de establecer el diagnóstico correcto. Debido a sus características, el TOQ debe tener un tratamiento más agresivo, en comparación con los quistes odontogénicos, donde un seguimiento a mediano y largo plazo es obligatorio.

Collagen and elastic fibers in odontogenic entities: analysis using light and confocal laser microscopic methods.

Dentigerous cyst (DC) and keratocystic odontogenic tumor (KOT) are odontogenic lesions arising from epithelial elements, such as those observed in dental follicles (DF), that have been part of the tooth forming apparatus. These lesions show different clinical and histological characteristics, as well as distinct biological behavior. This study aimed to qualify and quantify collagen and elastic fibers by means of histochemical techniques with light and confocal laser microscopic methods in three odontogenic entities. Eleven DF, 13 DC (n=10 with inflammation, n=3 without inflammation) and 13 KOT were processed to the following techniques: Hematoxylin and Eosin, Masson's Trichrome, Picrosirius, Direct Blue, and Orcein. DF and DC without inflammation exhibited collagen with similar characteristics: no parallel pattern of fiber orientation, thick fibers with dense arrangement, and absence of distinct layers. A comparison between DC with inflammation and KOT revealed similar collagen organization, showing distinct layers: thin collagen fibers with loose arrangement near the epithelium and thick fibers with dense arrangement in distant areas. The only difference found was that KOT exhibited a parallel collagen orientation in relation to the odontogenic epithelia. It may be suggested that the connective tissue of DC is a reactive tissue, inducing an expansive growth associated with fluid accumulation and inflammatory process, which in turn may be present as part of the lesion itself. In KOT, loosely arranged collagen may be associated with the behavior of the neoplastic epithelium.

Syndecan-1 (CD138) and Ki-67 expression in odontogenic cystic lesions

The aim of this study was to assess the immunohistochemical expression of syndecan-1 (CD138) and Ki-67 in radicular cysts (RC), dentigerous cysts (DC) and keratocystic odontogenic tumors (KOT). Thirty-five RC, 22 DC and 17 KOT were used in the study and immunohistochemical reactions using anti-syndecan-1 and anti-Ki-67 antibodies were performed by the streptavidin-biotin-peroxidase method. Fisher's exact test and Spearman's correlation coefficient were used for statistical analysis of data. Among the studied lesions, no differences in the syndecan-1 expression were observed, but the suprabasal expression of Ki-67 was significantly higher in KOT (p<0.0001), when compared with RC and DC. In RC, there was positive correlation between the expression (p=0.02) and intensity (p=0.0001) of syndecan-1 and between the intensity of syndecan-1 and Ki-67 expression (p=0.01). In the KOT, Ki-67 expression in the suprabasal layer correlated positively with the expression (p=0.01) and intensity (p=0.01) of syndecan-1. The expression of syndecan-1 does not seem to be a determinant factor of the distinct histopathological features and biological behavior of the studied lesions. Nevertheless, positive correlation between syndecan-1 and a cell proliferation marker was observed in RC and KOT.

O objetivo deste estudo foi avaliar a expressão imunoistoquímica de syndecan-1 (CD138) e Ki-67 em cistos radiculares (CR), cistos dentígeros (CD) e tumores odontogênicos queratocísticos (TOQ). Trinta e cinco CR, 22 CD e 17 TOQ foram utilizados no estudo e as reações imunoistoquímicas usando os anticorpos anti-syndecan-1 e anti-Ki-67 foram realizadas pelo método estreptavidina-biotina-peroxidase. Para análise estatística, o teste exato de Fisher e o coeficiente de correlação de Spearman foram utilizados. Entre as lesões estudadas, não foram observadas diferenças na expressão de syndecan-1, mas a expressão suprabasal de Ki-67 foi significativamente maior nos TOQ (p<0,0001), quando comparado aos CR e CD. No CR, havia correlação positiva entre a expressão (p=0,02) e intensidade (p=0,0001) de syndecan-1 e entre a intensidade de syndecan-1 e expressão de Ki-67 (p=0,01). No TOQ, a expressão de Ki-67 na camada suprabasal correlacionou positivamente com a expressão (p=0,01) e intensidade de expressão (p=0,01) de syndecan-1. A expressão de syndecan-1 não parece ser um fator determinante das características histopatológicas distintas e do comportamento biológico das lesões estudadas. Entretanto, correlação positiva entre syndecan-1 e um marcador de proliferação celular foi evidenciado em CR e TOQ.

Tumor odontogênico ceratocístico / Keratocystic odontogenic tumor

Introdução: O tumor odontogênico ceratocístico (TOC) é uma lesão que requer considerações especiais por conta de seu comportamento clínico e de seus aspectos histopatológicos específicos. O presente estudo tem por objetivo apresentar um caso de TOC enfatizandosuas características radiográficas e histopatológicas. Relato decaso: Paciente de 43 anos apresentou imagem radiolúcida unilocular localizada na região posterior do corpo mandibular, no lado esquerdo,estendendo-se até o ramo ascendente, observada em uma radiografia panorâmica. Foi submetida a um exame tomográfico seguido de biópsia incisional para posterior exame histopatológico, no qual foi observada cavidade patológica revestida por epitélio paraceratinizado,exibindo camada basal disposta em paliçada e que evidenciava células com hipercromatismo nuclear, confirmando tratar-se de umTOC. Conclusão: O conhecimento por parte dos cirurgiões-dentistas de lesões tumorais de natureza odontogênica, especialmente do TOC,é de fundamental importância, proporcionando assim um diagnóstico correto dessas lesões, evitando que elas assumam grandes dimensões e, por conseguinte, levem o paciente a uma mutilação significativa.

Introduction: The keratocystic odontogenic tumor (KOT) is a lesion that requires special considerations due to its clinical behavior and specific histopathological aspects. This study aims to present a case of KOT emphasizing its radiological and histopathological characteristics.Case Report: In a panoramic radiograph a female 43-year-old patient presented a radiolucent unilocular image located in the left side of the posterior region of the mandible, extending up to ascending branch.She was submitted to computed tomography scan followed by anincisional biopsy for subsequent histopathological examination, in which a pathological cavity with parakeratinized epithelium was observed,showing basal layer containing cells with nuclear hyperchromatism,thus confirming a KOT. Conclusion: The dentists knowledge regardingodontogenic tumor lesions, especially KOT, is primary important inorder to provide an accurate diagnosis of this lesions and to avoid theirgrowth, which could result in significant injuries to the patient.