Diffusion-Weighted MR Imaging of Unicystic Odontogenic Tumors for Differentiation of Unicystic Ameloblastomas from Keratocystic Odontogenic Tumors

OBJECTIVE: Differentiating unicystic ameloblastomas from keratocystic odontogenic tumors (KCOT) is necessary for the planning of different treatment strategies; however, it is difficult based on conventional CT and MR sequences alone. The purpose of this study was to investigate the utility of diffusion-weighted imaging (DWI) and apparent diffusion coefficients (ADCs) in the differentiation of the two tumors. MATERIALS AND METHODS: We prospectively studied 40 patients with odontogenic cysts and tumors of the maxillomandibular region using conventional MR imaging and DWI. ADCs were measured using 2 b factors (500 and 1000). RESULTS: Unicystic ameloblastomas (n = 11) showed free diffusion on DWI and a mean ADC value of 2.309 ± 0.17 × 10-3 mm2/s. KCOT (n = 15) showed restricted diffusion on DWI with a mean ADC value of 0.923 ± 0.20 × 10-3 mm2/s. The ADC values of unicystic ameloblastomas were significantly higher than those of KCOT (p < 0.001, Mann-Whitney U-test). An ADC cut-off value of 2.0 × 10-3 mm2/s to differentiate KCOT and unicystic ameloblastomas resulted in a 100% sensitivity and 100% specificity. Dentigerous cysts (n = 3) showed restricted diffusion on DWI and similar ADC values (1.257 ± 0.05 × 10-3 mm2/s) to those of KCOT. CONCLUSION: Diffusion-weighted imaging and ADC determination can be used as an adjuvant tool to differentiate between unicystic ameloblastomas and KCOT, although the ADC values of dentigerous cysts overlap with those of KCOT.

Correlating multi-detected computed tomography findings with conventional radiography, operative and histopathological examination in mandibular swellings

Introduction: Mandibular swelling are common entity in dental and general surgery practice requiring prompt intervention, imaging techniques such as plain radiography and especially multidetector computed tomography (MDCT) which offer the potential to improve the outcome buy increasing the accuracy of diagnosis. Materials and methods: In the present study, 30 patients with clinically diagnosed mandibular swelling were evaluated with conventional radiography; MDCT and HPE wherever performed to establish the value of MDCT and to evaluate the role of MDCT in establishing the diagnosis. Results: In the present study, majority of the cases were in the age group of 21-30 years with an male: female ratio of 1:1.5. Most commonly found lesions were odontogenic lesions (27 out of 30 cases) accounting about 90% of all the mandibular swellings. Among the odontogenic lesions ameloblastomas was the most common diagnosis followed by odontogenic keratocyst constituting 48%and 29% respectively in the present study, unilocular ameloblastoma were more common than multiocular ameloblastomas i.e. 7 out 13 cases (53.85%) among non-odontogenic lesions, central ossifying fibroma was the common diagnosis i.e. 2 out of 3 cases (67%) in the present study, being lesions were common than malignant i.e. 28 out of 30 cases (93.3%) and 2 out of 30 cases (06.66%) were malignant. Mohammed Abdul Azhar. Correlating multi-detected computed tomography findings with conventional radiography, operative and histopathological examination in mandibular swellings. IAIM, 2017; 4(9): 119-124. Page 120 Conclusions: MDCT provided excellent visualization and delineation of mandibular anatomy when compared to plain radiography. MDCT images ideal for pre-operative evaluation as they provide thin sections (<l mm) multiplanar reconstruction in the coronal, sagittal, panoramic and para-axial planes. In addition information regarding the appearance, location, course of anatomic structure in the jaws. Value rendering technique provides near real 3 dimensional appearance of the lesion for the dental surgeon to plan accordingly.

Expresión de p53 y Ki-76 en ameloblastomas acantosos / Expression of P53 and KI-67 in ameloblastomas acanthomatous

El Ameloblastoma Acantomatoso es una variante histopatológica donde la parte central de las células Epiteliales Odontogénicas sufren una metaplasia escamosa. Este cambio biológico podría darle a esta forma de ameloblastoma características de mayor agresividad y recidiva. El objetivo del presente trabajo fue determinar la expresión de las proteínas p53 y Ki-67 en ameloblastomas acantomatosos. Metodología: 12 especímenes diagnosticados histopatológicamente como ameloblastoma acantomatoso fueron examinados y la expresión de p53 y Ki-67 determinada inmunohistoquímicamente usando los anticuerpos anti-humanos clones DO-7 y MIB-1 respectivamente (DAKO®). La expresión de ambas proteínas fue evaluada mediante microscopio de luz y la intensidad y número de núcleos positivos semicuantificados y analizados mediante estadística descriptiva. Resultados: La expresión de p53 fue observada en el 50% de los casos tanto en las células basales como centrales de las islas tumorales. La expresión de Ki-67 fue observada en el 66,7% de los casos, en su mayoría tanto en las células basales como tumorales y en su totalidad de fuerte intensidad. Conclusiones: La expresión de p53 y Ki-67 en los ameloblastomas acantomatosos sugiere una proliferación celular acelerada y por ende una mayor capacidad de crecimiento. Estas proteínas podrían conformar una herramienta para la selección de tratamientos más radicales en ameloblastomas que las expresen

Acanthomatous Ameloblastoma is a histopathological variant where the central portions of odontogenic epithelial cells undergo squamous metaplasia. This biological change could confer more aggressive features and recurrence to the tumour. The aim of this study was to determine the expression of p53 and Ki-67 in acanthomatous ameloblastoma. Methods: 12 specimens histologically diagnosed as acanthomatous ameloblastomas were examined and the expression of p53 and Ki-67 determined immunohistochemically using anti-human antibody clone DO-7 and MIB-1 respectively (DAKO ®). The expression of both proteins was assessed by light microscopy and the intensity and number of positive cells semi-quantified and analyzed using descriptive statistics. Results: The expression of p53 was observed in 50% of the cases both in the basal cells as tumor central islands. The Ki-67 expression was observed in intensely in 66.7% of cases, mainly on basal cell as central. Conclusions: The expression of p53 and Ki-67 in acanthomatous ameloblastomas suggests accelerated cell proliferation and therefore increased capacity for growth. Expression of these proteins may constitute a tool for prognosis and treatment selection

Ameloblastomas: aspectos clínicos e terapêuticos / Ameloblastomas: clinical and therapeutic aspects

Introdução: Os tumores odontogênicos correspondem a menos de 1% dos tumores da cavidade oral, sendo os ameloblastomas bastante freqüentes, com ocorrência na mandíbula em cerca de 80% dos casos. A maior incidência na mandíbula é nos molares, como também na maxila. Objetivo: Avaliar resultados do tratamento de pacientes portadores de ameloblastoma. Pacientes e método: Foram analisados os prontuários de 12 pacientes com ameloblastoma, sendo 10 deles na mandíbula e dois em maxila, no período de 1996 a 2005. A média de idade foi de 37,7 anos com predominância do gênero feminino, com sete casos, sendo 10 pacientes caucasianos. As queixas clínicas predominaram com abaulamento na cavidade oral, alteração de posição e amolecimento dentário. A avaliação pré-operatória constou de exame físico geral e específico, exames radiológicos, exames laboratoriais pré-operatórios e revisão de exame anátomo-patológico. Através de radiografia panorâmica da mandíbula e/ou tomografia computadorizada da cavidade oral, foram analisadas extens??o da lesão e sua relação com dentes e presença de erosão óssea na mandíbula. Resultados: O tratamento foi a ressecção da lesão e reconstrução imediata com enxerto ósseo de crista ilíaca, com exceção de dois pacientes. No pós-operatório, houve dois casos de deiscência da sutura intra-oral e exposição da placa de reconstrução, que obrigou sua retirada e dos enxertos ósseos. Não tivemos caso de recidiva tumoral. Conclusões: Os ameloblastomas ainda apresentam dificuldade em seu diagnóstico precoce, devido à pouca sintomatologia inicial e também por causa de sua raridade. O tratamento preferencial para os tumores mais avançados é a ressecção ampla com reconstrução imediata.

Introduction: Odontogenic tumors correspond to less than 1% of the tumors of the oral cavity and, among them, the ameloblastomas are the most frequent, with 80% of the cases occurring in the jaw, mainly in molar area, what also happens when they appear in the maxilla. Objective: to evaluate the outcome of the treatment in patients with ameloblastoma. Patients and methods: We analyzed the medical charts of 12 patients with ameloblastoma, with 10 cases in the jaw and 2 in the maxilla, during the period from 1996 to 2005. The average age was of 37.7 years-old with 7 cases in women and 10 cases in Caucasian patients. The clinical complaints prevailed with oral cavity swelling and change of the dental position. The preoperative evaluation consisted of general and specific physical examination and radiological examinations (panoramic X ray and/or CT scan). The image exams were employed to analyze the extension of the lesion and its relationship with dental elements and the presence of erosion of the external and internal boards of the jaw. Results: All patients were treated with resection of the lesion and immediate reconstruction with crest iliac bony graft, except for two patients. The postoperative complications were two cases of infection with intraoral suture line dehiscence and exposition of the reconstruction plate and consequent retreat of the plates and bony grafts. Conclusion: The ameloblastomas still present with difficulty in early diagnosis due to the small importance that the patients give for the initial symptoms and also its rarity. The preferential treatment for the most advanced tumors is the wide resection with immediate reconstruction.

Ameloblastoma removed by curettage and enucleation after SSRO: case report

Análise imuno-histoquímica das citoqueratinas em ameloblastoma e tumor odontogênico adenomatóide / Immunohistochemical analysis of cytokeratins in ameloblastoma and adenomatoid odontogenic tumor

OBJETIVO: O presente trabalho teve por objetivo traçar o perfil das citoqueratinas (CKs) 7, 8, 10, 13, 14, 18 e 19 em ameloblastomas e tumor odontogênico adenomatóide (TOA) visando contribuir para o entendimento da histogênese desses tumores e somar com os resultados já relatados na literatura. MATERIAL E MÉTODO: do arquivo do Laboratório de Anatomia Patológica do Departamento de Odontologia da Universidade Federal do Rio Grande do Norte (UFRN) foi selecionada uma amostra com dez casos de ameloblastomas e oito de TOA para o estudo imuno-histoquímico, utilizando-se anticorpos anti-CKs pelo método da estreptoavidina-biotina. RESULTADOS: Observou-se que nos ameloblastomas a CK 14 esteve presente em todos os casos, enquanto a CK 19 foi observada nas células periféricas (oito casos) e nas centrais (cinco casos). Para os TOA, observou-se imunopositividade para a CK 14 em todos os casos, enquanto a CK 19 esteve marcada predominantemente nas células ductais (seis casos). CONCLUSÃO: As citoqueratinas são expressas de forma variada nos ameloblastomas e nos TOA, os quais preservam CK típicas do germe dental em estágios avançados do desenvolvimento, confirmando sua origem exclusiva a partir do epitélio odontogênico e não se evidenciando CK características do epitélio escamoso.

OBJECTIVES: The aim of the present study was to describe the immunohistochemical expression of cytokeratins (CKs) 7, 8, 10,13, 14, 18 and 19 in the epithelial components of ameloblastomas and adenomatoid odontogenic tumor (AOT). The results were compared and histogenesis discussed. MATERIAL AND METHOD: Specimens of ten ameloblastomas and eight adenomatoid odontogenic tumors were examined by immunohistochemistry using streptavidin-biotin-peroxidase complex method and anti-CKs antibody. The sample was obtained from Department of Oral Pathology, Federal University of Rio Grande do Norte. RESULTS: Immunohistochemical reactivity for CK14 was detected in all cases of ameloblastomas, and the expression of CK19 was diffusely present in peripheral cells (eight cases) and in central cells of five ameloblastomas. In AOTs, immunopositivity for CK14 was detected in all cases, whereas CK 19 was predominantly expressed in ductal cells (six cases). CONCLUSION: The CKs was expressed by several forms in ameloblastomas and AOTs, that have shown typical CKs of dental germ suggesting that these tumors have odontogenic epitheilial differentiation, whereas it has not evinced proper CKs of squamous epithelial.