New WHO odontogenic tumor classification: impact on prevalence in a population

Abstract Objectives: This study approaches the history of reclassifications and redefinitions around the odontogenic keratocyst (OK), as proposed by the World Health Organization (WHO), and aims to understand the impact of those changes on the prevalence and epidemiology of odontogenic tumors (OTs). Methodology: Cases of OTs diagnosed in an Oral Pathology service between January 1996 and December 2016 were reviewed. Demographic data of patients such as age, gender and site of lesions were retrieved from their respective records. Results: Within the studied period, 7,805 microscopic reports were elaborated and 200 (2.56%) of these were diagnosed as OTs. Out of these 200, between 1996 and 2005, prior to the 2005 WHO classification, there were 41 (20.5%) OTs cases, being odontoma the most frequent (23; 56.09%), followed by ameloblastoma (8; 19.51%) and myxoma (03; 7.31%). Between 2006 and 2016, after the previous 2005 WHO classification there were 159 (79.5%) OTs, being odontogenic keratocystic tumor (KCOT) the most frequent (68; 42.76%), followed by odontoma (39; 24.52%) and ameloblastoma (21; 13.20%). Conclusions: As of today, the most recent WHO classification to be followed brings KCOT back to the cyst category, which will impact on the prevalence and epidemiology of OTs; thus, this study was able to identify a considerable increase (287.80%) in the prevalence of OTs when the 2005 WHO classification was utilized. Despite being an important academic exercise, classifying odontogenic lesions and determining whether to place the odontogenic keratocyst in a cyst or tumor category is crucial to establish the correct diagnosis and treatment to follow, whether by oral medicine or oral surgery specialist, or by the general practitioner.

Reclassification and treatment of odontogenic keratocysts: A cohort study

Abstract: The odontogenic keratocyst (OKC) is a recurrent cyst that has been recently reclassified from an odontogenic tumor to an odontogenic cyst. The aim of the present study was to investigate its treatment and address issues related to its association with nevoid basal cell carcinoma syndrome (NBCCS). Lesions from the cohort of patients included in the present study consisted of 40 OKCs, of which 27 lesions were treated by enucleation (GE) and 13 underwent decompression (GD). Complementary treatment occurred in 38 (95%) lesions, of which 10 underwent isolated peripheral ostectomy (GO) and 28 underwent peripheral ostectomy combined with Carnoy's solution (GC). Thirteen lesions were associated with NBCCS (GS), while the others (n=27) were non-syndromic lesions (GnS). The recurrence-free periods (RFP) in the sample groups were compared using the Kaplan-Meier function and log-rank test at a significance level of 5% (p < 0.05) and were used to calculate the cumulative risk of recurrence (CRR) in each postoperative year. During the follow-up period, which had a mean of 43.5 months (range: 12-102 months), six (15%) recurrences were diagnosed. There was no significant difference among the RFP for the compared groups (p > 0.05) or increased CRR for the decompression (15.4%) over five years. Application of Carnoy's solution did not increase the efficacy of the peripheral ostectomy, but was related to a CRR of 0% for the syndromic lesions over five years. Therefore, 1) decompression did not increase the recurrence risk; 2) peripheral ostectomy demonstrated a similar efficacy as the combination with Carnoy's solution; 3) the association of NBCCS did not seem to significantly influence OKC recurrence; and 4) syndromic lesions seem to behave in the same manner as non-syndromic lesions when submitted to complementary treatments.

Application of endoscopy to treat mandibular keratocystic odontogenic tumors

The aim of this study was to evaluate the feasibility of endoscopy to remove keratocystic odontogenic tumors (KCOTs) with virtual 3D mandibular images. Fifteen patients (mean age, 40.27±14.58 years) who underwent endoscopic mandibular KCOT enucleation between May 2009 and October 2009 were included. Virtual 3D mandibular reconstructions derived from computed tomography (CT) imaging were generated for all patients. Recurrence and pathological fracture were evaluated as the primary outcome variables at 1 and 12 months after operation. Secondary infection and inferior alveolar nerve injury were evaluated as the secondary outcome variables at 1 and 6 months after operation. None of the 15 patients exhibited signs of recurrence or pathological fracture after operation. During long-term follow-up, no symptoms of inferior alveolar nerve injury or secondary infection were observed and no signs of recurrence were found in any of the patients. Endoscopy helps surgeons to remove mandibular KCOTs with small incisions. Moreover, endoscopy can provide clear and magnified views and help to avoid damage to the inferior alveolar neurovascular bundle. Therefore, under the support of preoperative virtual 3D mandibular images, the application of endoscopy to remove the tumors should be considered to be a treatment option for KCOTs.

Displasia cemento ¢sseo periapical e o diagn¢stico diferencial com lesães de origem endod“ntica – relato de caso / Periapical cemento osseous dysplasia and differential diagnosis with lesions of endodontic origin – case report

A Displasia Cement ria Periapical ‚ um tumor odontogˆnico de origem mesenquimal, derivado do ligamento periodontal. Por nÆo apresentar sinais e sintomas, normalmente ‚ descoberto em exames radiogr ficos de rotina. O aspecto radiogr fico ‚ semelhante a lesães periapicais de origem endod“ntica, o que pode confundir o cl¡nico no momento do diagn¢stico e lev -lo a um tratamento desnecess rio. O objetivo deste trabalho foi relatar um caso cl¡nico de Displasia Cement ria Periapical, apresentar as caracter¡sticas, bem como ressaltar a importƒncia do correto diagn¢stico diferencial.

Periapical Cemento Dysplasia is an odontogenic tumor of mesenchymal origin, derived from the periodontal ligament. Because it doesn't show signs and symptoms, it is usually discovered on routine radiographic examination. The radiographic appearance is similar to periapical lesions of endodontic origin, which can confuse the clinician at the time of diagnosis and lead to an unnecessary treatment. The aim of this study was to report a case of Periapical Cemento Dysplasia, and present its characteristics as well as underscoring the importance of the proper diagnosis.

Ameloblastoma: report of two cases and a brief literature review / Ameloblastoma: presentación de dos casos y una breve revisión de la literatura

Ameloblastoma is an uncommon odontogenic neoplasm that accounts for approximately 10 percent of all tumors originating from gnathic bones. Although its growth is localized, the tumor can also be infiltrative and persistent; however, its behavior is usually benign. The mandible is the most commonly affected site, and ameloblastoma is most frequently diagnosed between the fourth and fifth decades of life. In addition to a brief review of the literature, the present study discusses the clinical, imaging, histopathological and prognostic characteristics of these tumors by presenting two case reports. In these cases, the patients were aged 40 and 66 years, of different sexes and ethnicities and presented with the same complaint regarding localized and asymptomatic swelling. Both cases occurred in the posterior region (but on opposite sides) of the mandible. The patients were initially subjected to clinical examination and imaging of the face, followed by incisional biopsy to confirm (in both cases) the diagnosis of multicystic intraosseous ameloblastoma with a plexiform pattern. Both patients were treated by wide resection of the lesion (with safety margins), and only one patient experienced tumor recurrence. After 42 and 68 months of follow-up, the patients are still alive and show no signs of recurrence. Clinical and imaging findings aid in the differential diagnosis of ameloblastomas; however, histopathological evaluation is essential for its definitive diagnosis. Early diagnosis and precise detection of the borders to provide adequate safety margins during the surgical resection of the tumor are necessary to achieve successful treatment and recurrence-free survival for solid ameloblastomas.

El ameloblastoma es un tumor odontogénico infrecuente que representa aproximadamente 10 por ciento de todos los tumores que se originan a partir del maxilar y mandíbula. Aunque su crecimiento es localizado, el tumor puede ser infiltrante y persistente, y su comportamiento suele es benigno. La mandíbula es el sitio más comúnmente afectado, y el ameloblastoma se diagnostica con más frecuencia entre la cuarta y quinta década de la vida. Junto con una breve revisión de la literatura, el presente estudio analiza los datos clínicos, imágenes, características histopatológicas y pronóstico de estos tumores mediante la presentación de dos casos. En estos casos, los pacientes tenían entre 40 y 66 años, eran de diferentes sexos y grupos étnicos, que presentan la misma queja en relación con aumento de volumen localizado y asintomática. Ambos casos ocurrieron en la región posterior (pero en lados opuestos) de la mandíbula. Los pacientes fueron sometidos inicialmente a un examen clínico e imagenológico, seguido de la biopsia incisional para confirmar (en ambos casos) el diagnóstico de ameloblastoma multiquístico intraóseo tipo plexiforme. Ambos pacientes fueron tratados con amplia resección de la lesión (con márgenes de seguridad), y sólo un paciente presentó recurrencia del tumor. Después de 42 y 68 meses de seguimiento, los pacientes están vivos y sin signos de recurrencia. Los resultados clínicos e imagenológicos ayudan en el diagnóstico diferencial del ameloblastomas, sin embargo, la evaluación histopatológica es esencial para su diagnóstico definitivo. El diagnóstico prematuro y la precisa detección de las márgenes de la lesión proporcionan márgenes de seguridad adecuadas durante la resección quirúrgica del tumor y son necesarios para lograr el éxito del tratamiento y la supervivencia libre de recurrencia en los ameloblastomas sólidos.

Tumores odontogênicos: estudo clínico-patológico de 238 casos / Odontogenic tumors: clinical and pathology study of 238 cases

Os tumores odontogênicos são neoplasias que se desenvolvem exclusivamente nos ossos gnáticos, originando-se dos tecidos odontogênicos por proliferação de tecido epitelial, mesenquimal ou ambos. OBJETIVO: Avaliar a incidência de tumores odontogênicos em determinada instituição e comparar com outros estudos da literatura mundial. FORMA DE ESTUDO: Estudo de coorte transversal. MATERIAL E MÉTODO: O material do estudo foi levantado a partir dos registros de pacientes com tumores odontogênicos, no período de janeiro de 1992 a março de 2007 (15 anos). Foram incluídos os casos de pacientes que se enquadravam na Classificação Histológica da Organização Mundial de Saúde (OMS) de 2005. Foram analisados os indicadores gênero, faixa etária, localização anatômica, tipo histológico e presença de sintomatologia. RESULTADOS: Os tumores odontogênicos constituíram 4,76 por cento dentre todas as lesões biopsiadas dentro do período estudado. A idade média dos pacientes foi de 30,7 anos, 57 por cento dos pacientes eram do gênero masculino. O tumor odontogênico ceratocístico foi o tipo histológico mais prevalente (30 por cento), seguido do ameloblastoma (23,7 por cento). Quanto à presença de sintomatologia, 75,7 por cento dos casos apresentaram-se assintomáticos. CONCLUSÃO: Os tumores odontogênicos parecem ter discreta predileção pelo gênero feminino, segunda e terceira décadas de vida, sendo mais freqüentes na mandíbula e, na maioria dos casos apresentam-se assintomáticos.

Odontogenic tumors are neoplasms that develops exclusively in the gnathic bones; they originate from odontogenic tissues, by epithelial or mesenchymal proliferation, or both. AIM: To evaluate the incidence of odontogenic tumors in a specific institution, and to compare these findings with other studies in the literature. STUDY FORMAT: A cross-sectional cohort retrospective study. MATERIAL AND METHOD: The sample was obtained from the files of patients with odontogenic tumors diagnosed between January 1992 and March 2007 (15 years). Cases in which the diagnosis could be adapted to the new World Health Organization (WHO) of 2005 were included. Data such as gender, age, anatomical site, histological type and symptomatology were analyzed. RESULTS: Odontogenic tumors were 4.76 percent of all biopsied lesions within the studied period. The mean age was 30.7 years; 57 percent of the patients were male. The keratocystic odontogenic tumor was the most prevalent histological type (30 percent), followed by the ameloblastoma (23,7 percent). The rate of asymptomatic cases was 75.7 percent. CONCLUSION: Odontogenic tumors occurred more frequently in females, in the second and third decades of life, and more commonly in the mandible; most cases were asymptomatic.

Central epithelial odontogenic ghost cell tumor: a case report / Tumor epitelial odontogênico central de células fantasmas: relato de caso

Os autores descrevem um caso de tumor epitelial odontogênico de células fantasmas e discutem a verdadeira etiologia do cisto odontogênico calcificante, bem como suas várias descriçöes e subdivisöes de acordo com outros autores e com a descriçäo da Organizaçäo Mundial de Saúde