[Three-dimensional radiographic features of calcifying odontogenic cyst and calcifying epithelial odontogenic tumor].

OBJECTIVE: To analyze the three-dimensional radiographic characteristics of calcifying odontogenic cyst and calcifying epithelial odontogenic tumor using spiral computed tomography (CT) and cone-beam computed tomography (CBCT). METHODS: Clinical records, histopathological reports, and CBCT or non-enhanced spiral CT images of 19 consecutive patients with calcifying odontogenic cyst (COC) and 16 consecutive patients with calcifying epithelial odontogenic tumor (CEOT) were retrospectively acquired, and radiographic features, including location, size, expansion, internal structure and calcification, were analyzed. RESULTS: Among the 19 COC cases (12 males and 7 females, with an average age of 27 years), 89.5% (17/19) of the lesions originated from the anterior and premolar areas, 100.0% of them exhibited cortex expansion, and 78.9% had discontinued cortex. Among the 16 CEOT cases (3 males and 13 females, with an average age of 36 years), 81.3% (13/16) of the lesions were in the premolar and molar areas, 56.3% of them exhibited cortex expansion, and 96.8% had discontinued cortex. According to the distribution of internal calcifications, these lesions were divided into: Ⅰ (non-calcification type): absence of calcification; Ⅱ (eccentric marginal type): multiple calcifications scattered along one side of the lesion; Ⅲ (diffused type): numerous calcifications diffusely distributed into the lesion; Ⅳ (plaque type): with a ≥ 5 mm calcified patch; Ⅴ (peri-coronal type): multiple calcifications clustered around impacted teeth. Calcifications were present in 73.7% of COC lesions, including 9 type Ⅱ, 3 type Ⅲ and 2 type Ⅳ lesions, and 42.8% of CEOT lesions had calcification images, including 2 type Ⅲ and 5 type Ⅴ lesions. Six COC lesions had odontoma-like images. Moreover, 8 of 9 type Ⅰ CEOTs were histologically Langerhans cell-rich subtype, which had a smaller size (with an average mesiodistal diameter of 17.8 mm) and were not associated with impacted teeth. CONCLUSION: COC lesions tended to originate from the anterior part of the jaw and exhibit cortex expansion, and were sometimes associated with odontoma. CEOT commonly occurred in the posterior jaw and had discontinued cortex. Two lesions had significantly different calcification map. Over 70% of COC lesions had calcification images, which were mostly scattered along one side of the cysts, far from the impacted teeth. Approximately 60% of CEOT lesions exhibited smaller size and non-calcification, and the remaining CEOT cases often had calcification images clustered around the impacted teeth.

Quiste odontogénico calcificante. Análisis de características clínicas e imagenológicas en reportes de casos / Calcifying odontogenic cyst. Analysis of clinical and imaging characteristics in case reports

Introducción: El quiste odontogénico calcificante (QOC) es un quiste odontogénico raro de los maxilares, que en un gran número de casos se asociaa otras patologías. Debido a esto, la presentación clínica e imagenológica puede variar. El objetivo del presente trabajo fue determinar las características clínicas e imagenológicas del QOC intraóseo, sin asociación a otras patologías, publicadas en reportes de casos.Material y métodos:Se realizó una búsqueda en PubMed, Scopus, Epistemonikos y Web of Science, de reportes de casos de QOC intraóseo, sin asociación a otras patologías, que tuvieran exámenes imagenológicos y diagnóstico histopatológico.Resultados:Se incluyeron 20 artículos, con 21 casos clínicos. El QOC sepresentó principalmente en la segunda década de vida, sexo masculino y zona posterior mandibular. El aumento de volumen estuvo presente en la mayoría de los casos. El dolor, alteraciones de mucosa y movilidad dentaria se observaron en un menor porcentaje. Radiográficamente se observó una lesión de densidad mixta, unilocular, de límites definidos y regulares, con expansión de corticales. La perforación, desplazamiento dentario y reabsorción radicular fueron poco comunes. El tamaño fue principalmente mayor a 3cm.Conclusiones:La información clínica e imagenológica fue escasa en todos los artículos incluidos. La mayoría de las características que no coinciden con lo reportado por la literatura podrían tener su explicación en el hecho de que los casos publicados suelen ser atípicos.En la presenterevisión se encontraron características del QOC diferentes a las reportadas, que son relevantes para el diagnóstico diferencial.(AU)

Introduction: Calcifying odontogenic cyst (COC) is a rare odontogenic cyst of the jaws, which in many cases is associated with other pathologies and can generate differences in terms of clinical and imaging presentation. The aim of this article was to determinate the clinical and imaging characteristics of intraosseous COC, without association to other pathologies, published in case reports.Material and methods:A search in PubMed, Scopus, Epistemonikos and Web of Science was performed, for case reports of intraosseous COC, without association to other pathologies, which had imaging examinations and histopathological diagnosis.Results:20 articles were included, with 21 clinical cases. COC was found to occur mainly in the second decade of life, male sex, and mandibular posterior area. Swelling was present in most cases. Pain, mucosal alterations, and dental mobility were observed in a lower percentage. Radiographically, a mixed density lesion, unilocular, with defined and regular limits, which generates cortical expansion was observed. Perforation, tooth displacement and root resorption were uncommon. The size was mainly larger than 3cm.Conclusion:Clinical and imaging information was found to be scarce in all articles included in this review. Most of the characteristics that did not coincide with what is reported by the literature could be explained by the fact that published cases are usually atypical. In this review, different COC characteristics than those previously reported were found, which are relevant for differential diagnosis.(AU)

Dentinogenic ghost cell tumor associated with odontoma: report of a rare case and review of literature.

Dentinogenic ghost cell tumor (DGCT) is an uncommon odontogenic tumor considered to be the solid, tumorous variant of calcifying odontogenic cyst. DGCT is characterized by islands of ameloblastoma-like epithelial cells that resemble the enamel organ, the presence of ghost cells, and dentinoid material. This article reports a rare case of dentinogenic ghost cell tumor associated with an odontoma in an adult patient, with a review of the literature. To the best of the authors' knowledge, there have only been four case reports of DGCT associated with odontoma, all of which occurred in children and adults younger than 30 years old.

Análise imuno-histoquímica da Yes-Associated Protein (YAP) e sua influência sobre a proliferação celular e a apoptose em lesões odontogênicas epiteliais benignas / Immunohistochemical analysis of Yes-Associated Protein (YAP) and its influence on cell proliferation and apoptosis in benign epithelial odontogenic lesions

Introdução: Os cistos e tumores odontogênicos são lesões que apresentam comportamento biológico heterogêneo e patogênese ainda não totalmente esclarecida. A Yes-associated protein (YAP) atua como um regulador transcricional de genes envolvidos na proliferação celular e na apoptose, participando da ativação de vias associadas ao crescimento cístico e à progressão neoplásica. Objetivo: Analisar a expressão imuno-histoquímica da proteína YAP e correlacioná-la com marcadores envolvidos na proliferação celular e na apoptose em lesões odontogênicas epiteliais benignas. Metodologia: A amostra consistiu de 95 casos de lesões odontogênicas - 25 cistos dentígeros (CDs), 30 CO não sindrômicos (COs), 30 AMB convencionais (AMB-Cs) e 10 AMB unicísticos (AMB-Us) -, além de 10 espécimes de folículo dentários (FD). Foi realizada coleta dos dados clinico-demográficos dos casos, bem como análise morfológica para melhor caracterização da amostra. Os cortes histológicos foram submetidos à técnica imuno-histoquímica através da utilização dos anticorpos YAP, ciclina D1, Ki-67 e Bcl-2, e a análise da expressão destes foi realizada quali-quantitativamente, mediante metodologia adaptada. Os dados coletados seguiram para análise descritiva e estatística (p ≤ 0,05). Resultados: Houve discreta predileção por mulheres (n = 55; 57,6%) e por indivíduos na faixa etária dos 21 aos 40 anos (n = 50; 47,6%), sendo a região posterior de mandíbula mais afetada (64%). A análise da imunoexpressão de YAP revelou maiores níveis de expressão em COs, especialmente nas camadas basal e parabasal, seguido dos AMB-Us e AMB-Cs, que demonstraram moderada imunorreatividade, predominantemente nas células periféricas. Além disso, houve diferenças significativas quanto à imunoexpressão de YAP entre os grupos analisados, com existência de correlações positivas e estatisticamente significativas entre YAP e ciclina D1 em CDs e AMB-Us, e entre YAP e Ki-67 em AMB-Us (p < 0,05). Todavia, entre a imunoexpressão YAP e Bcl-2, foi verificada ausência de correlação estatisticamente significativa. Conclusões: A YAP pode exercer influência sobre a proliferação celular do epitélio de cistos e tumores odontogênicos, auxiliando, assim, na progressão das diferentes lesões odontogênicas (AU).

Background: Odontogenic cysts and tumors present heterogeneous biological behavior, and their etiopathogenesis is not fully understood yet. Yes-associated protein (YAP) acts as a transcriptional regulator of genes involved in cell proliferation and apoptosis, activating pathways associated with cystic growth and neoplastic progression. Objective: To analyze the immunohistochemical expression of YAP protein and correlate it with markers involved in cell proliferation and apoptosis in benign epithelial odontogenic lesions. Methods: The sample consisted of 95 cases of odontogenic lesions - 25 dentigerous cysts (DCs), 30 non-syndromic odontogenic keratocyst (OKCs), 30 conventional AMB (C-AMBs), and 10 unicystic AMB (UAMBs) -, in addition to 10 specimens of dental follicles (DF). Clinicodemographic data collection was carried out, as well as morphological analysis for better characterization of the sample. The histological sections were submitted to the immunohistochemical technique using YAP, cyclin D1, Ki-67, and Bcl-2 antibodies, and their immunoexpression analysis was performed qualitatively and quantitatively, through an adapted methodology. The collected data were submitted for descriptive and statistical analysis (p ≤ 0.05). Results: There was a slight predilection for women (n = 55; 57.6%) and individuals aged between 21 and 40 years (n = 50; 47.6%), with the posterior region of the mandible as the most affected site (64%). Analysis of YAP immunoexpression revealed higher expression levels in OKCs, especially in the basal and parabasal layers, followed by U-AMBs and C-AMBs, which showed moderate immunoreactivity, predominantly in peripheral cells. In addition, there were significant differences in YAP immunoexpression between the analyzed groups, with positive and statistically significant correlations between YAP and cyclin D1 in DCs and U-AMBs, and between YAP and Ki-67 in U-AMBs (p < 0.05). However, between YAP and Bcl-2 immunoexpression, there was no statistically significant correlation. Conclusions: YAP may influence on the cell proliferation of odontogenic cysts and tumors epithelium, thus helping with the progression of the different odontogenic lesions (AU) .

Ghost Cell Odontogenic Carcinoma with Sarcomatous Transformation : Report of a Rare Case with Review of Literature.

Ghost Cell Odontogenic Carcinoma is a rare malignant odontogenic tumor that can appear as "de novo " or arises from malignant transformation of preexisting benign calcifying odontogenic cysts or dentinogenic ghost cell tumors after multiple recurrences. Ghost cell odontogenic carcinoma is histopathologically characterized by ameloblast-like islands of epithelial cells with aberrant keratinization, simulating a ghost cell, with varying amounts of dysplastic dentine. This article reports an extremely rare case of ghost cell odontogenic carcinoma with foci of sarcomatous change, involving maxilla andnasal cavity which arose from a previously existing recurrent calcifying odontogenic cysts in a 54-year-old man and reviews the features of this unusual and rare tumor. To the best of our knowledge, this is the first case of ghost cell odontogenic carcinoma with sarcomatous transformation to be reported till date. Owing to its rarity and unpredictability of clinical course, long -term follow up of patients with ghost cell odontogenic carcinoma, is mandatory for observation of recurrence and distant metastasis. Keywords: Ghost cell odontogenic carcinoma, maxilla, sarcoma, calcifying odontogenic cysts, ghost cells, odontogenic tumour.

Dentinogenic ghost cell tumor: a case report and review of the literature.

The purpose of this report is to highlight the presentation and review the clinical and histopathological features of DGCT. There have been 130 DCGT diagnoses reported in the literature. DGCT is part of the odontogenic ghost cell tumor family which also includes the calcifying odontogenic cyst (COC) and the ghost cell odontogenic carcinoma (GCOC). In June of 2018, a 48-year-old female presented with a painless, soft tissue growth overlying the right mandibular alveolar ridge. Further workup of the lesion included a panoramic radiograph and maxillofacial computed tomography (CT) which revealed a well-defined, multilocular lytic expansile radiolucency occupying the right mandibular body. An incisional biopsy of the right mandibular gingival mass was performed which revealed an unusual odontogenic neoplasm with mineralization and ghost cells. The patient was subsequently treated with excisional biopsy of the right mandibular lesion via enucleation and curettage. The specimen was sent to pathology and the tumor was found to have an epithelial neoplastic proliferation resembling that of ameloblastoma, accompanied by foci of ghost cells. Since mandibular bone was involved, a diagnosis of a benign central DGCT with extension into the overlying gingiva was rendered. She was successfully treated with excisional biopsy via enucleation and curettage and has no evidence of recurrence at three years post-operatively. DGCT can exhibit locally aggressive behavior and is characterized by ameloblastoma-like epithelial cells and the presence of dentinoid material and ghost cells.

Calcifying odontogenic cyst resembling clinical signs of vertical root fracture of a maxillary canine.

BACKGROUND: Calcifying odontogenic cyst (COC) can be misdiagnosed as a lesion of endodontic origin when it is in close proximity to the periradicular tissue, and pulp sensibility tests are indispensable for differential diagnosis. However, when the adjacent teeth are necrotic or already endodontically treated, diagnosis becomes challenging. CASE DESCRIPTION: In this case report, a maxillary canine with an inadequate root canal treatment was considered as the source of an endodontic infection. Eight months after the retreatment, the patient sought treatment for a buccal intraoral swelling and a deep periodontal pocket and was referred for cone-beam computed tomography with a provisional diagnosis of a vertical root fracture. The tomography revealed an extensive lesion buccally to the roots of the canine and the adjacent vital lateral incisor. An unusual extended external resorption of the root of the vital lateral incisor was also evident. This finding shifted the diagnostic thinking toward a lesion of nonendodontic origin. The lesion was surgically enucleated, and the histopathologic examination confirmed the diagnosis of a COC. PRACTICAL IMPLICATIONS: Clinicians always must bear in mind the chance of a nonendodontic lesion masquerading as a lesion of endodontic origin. Cone-beam computed tomography should be considered in cases of doubt or in lesions refractory to endodontic treatment, as it can provide information on the clinicopathologic features of the lesion.

Recurrent Dentinogenic Ghost Cell Tumor: A Case Report.

BACKGROUND Dentinogenic ghost cell tumor (DGCT) is a rare, locally invasive odontogenic neoplasm, considered as a solid variant of the calcifying odontogenic cyst (COC). DGCT accounts for only 2% to 14% of all COCs and less than 0.5% of all odontogenic tumors. It is characterized by an ameloblastomatous odontogenic epithelium and the presence of ghost cells and dentinoid material. CASE REPORT A 42-year-old male patient presented to the clinic with recurrent pain and swelling in the left maxilla. The patient had a similar presentation 3 years before, which had been managed by excisional biopsy and was misdiagnosed as unicystic ameloblastoma. Examination revealed a mild swelling in the left cheek with boney expansion on the posterior area of the left maxilla, with mobility in adjacent teeth. Radiographic evaluation revealed a large, well-demarcated radiolucent lesion with a sclerotic border involving the left maxilla and associated with root resorption in the adjacent teeth. An incisional biopsy was performed, and a diagnosis of DGCT was made. Segmental maxillectomy with safe margins was conducted, considering the aggressiveness of this pathological entity. The defect was reconstructed using the buccal fat pad. Histopathology examination confirmed the diagnosis of DGCT, which was characterized by ameloblastomatous odontogenic epithelium, dentinoid material, and ghost cells. One month follow-up revealed good healing of the surgical site. The patient was scheduled for regular follow-up. CONCLUSIONS This case reports the aggressiveness and high recurrence rates of DGCT. It is recommended to treat DGCT aggressively with safe margins and a long-term follow-up.

Differential diagnosis between calcifying odontogenic cyst and adenomatoid odontogenic tumor by computed tomography images.

OBJECTIVES: Calcifying odontogenic cysts (COC) and adenomatoid odontogenic tumors (AOT) have similar radiographic findings. We examined the radiographic and computed tomography (CT) images of patients histologically diagnosed with COC or AOT and identified their characteristic findings. METHODS: The subjects included 12 patients histologically diagnosed with COC or AOT (one female and five males per group), who underwent CT at our hospital between Nov 1998 and Jun 2019. The location of the lesion, impacted tooth, bone expansion, root resorption, tooth migration, calcified body, and presence or absence of a high-intensity zone in the marginal area of the lesion were examined. RESULTS: In patients with COC, five patients with COC exhibited bone expansion toward the buccal side. The lesion encompassing the crown was attached to the cement-enamel junction and contained a radiopaque lesion with a calcified body. In 6 patients with COC, irregularly shaped calcified bodies were observed with small tooth-like structures. In patients with AOT, all six patients with AOT exhibited bone expansion toward the buccal and lingual sides. The lesion encompasses a part of the tooth root or the entire tooth. Punctate calcification was observed within the lesion and the marginal area in three patients, and a high-intensity zone was observed in the marginal area of the lesion in two patients. CONCLUSION: We report imaging findings that may be characteristic of COC and AOT, suggesting that CT findings may be useful for differentiating between COC and AOT.

Pindborg tumor associated with a supernumerary tooth: a case report

The calcifying epithelial odontogenic tumor is a rare benign neoplasm that accounts for approximately 1% of all odontogenic tumors. Most of the cases occur in the posterior mandible, and a few involve the maxilla. Despite their relatively indolent biological behavior, tumors in the maxilla tend to grow fast. We report the case of a 33-year-old female patient exhibiting swelling in the right maxilla. An isodense area associated with an impacted supernumerary tooth was found on imaging examination. The histopathologic diagnosis was a calcifying epithelial odontogenic tumor. The treatment of choice was surgical removal of the lesion and associated dental elements. The patient has been followed up for 11 months and shows no signs of recurrence. Besides describing this case, we reviewed the literature on the association of calcifying epithelial odontogenic tumors with supernumerary teeth and found two case reports addressing this subject.

Primordial odontogenic tumor occurred in the maxilla with unique calcifications and its crucial points for differential diagnosis.

Primordial odontogenic tumor (POT) is a newly classified, mixed epithelial and mesenchymal odontogenic tumor, with only 17 reported cases to date. Herein, we report a case of POT that occurred in the right maxilla of a 10-year-old boy and reveal unique features in comparison with those previously reported. Radiologically, the lesion presented as a well-defined, unilocular radiolucency with notable radiopaque foci on the periphery. Microscopically, the tumor was mainly composed of dental papilla-like myxoid fibrous connective tissue, largely surrounded by non-keratinized squamous epithelium with numerous calcified particles, and partly enclosed by inner enamel epithelium-like columnar cells and enamel organ-like structures accompanied with cuboidal and/or stellate reticulum-like cells. Immunohistochemically, the epithelium tested positive for cytokeratin 14 and 19. Moreover, amelogenin and ameloblastin, matrix proteins relating to enamel formation, were positive in the covering epithelium. The tumor was enucleated as a whole, and no recurrence was recorded thereafter. Although the presence of numerous calcified particles was unique, we diagnosed this lesion as POT based on the above-described features. Furthermore, we emphasize the importance of the differential diagnosis of POT and other odontogenic tumors that resemble corresponding tooth germ components.

Ameloblastoma of the jaws in children: an evaluation of cases seen in a tertiary hospital in South-Eastern Nigeria.

BACKGROUND: Ameloblastoma is one of the most common benign odontogenic tumours in Nigeria. It is considered uncommon in children. MATERIALS AND METHODS: This is a retrospective study of pediatric patients with histopathological diagnosis of ameloblastoma seen over seven years at the Oral and Maxillofacial Surgery Department of the University of Nigeria Teaching Hospital, Enugu, Nigeria. Relevant information was retrieved from patients' records and data obtained were analysed using SPSS version 23, the chi-square test was used to compare qualitative variables, a p-value of <0.05 was considered as significant. RESULTS: One hundred and thirty-six cases of ameloblastoma in all age groups were seen within the period. Thirty of the cases met the requirement. The mean age of the patients was 14.4 STD 2.03 (range from 10-17) years. Fourteen (46.7%) patients were male while 16 (53.3%) were female giving a ratio of 1:1.1. The duration of the lesion ranged from 3 months to 72 months (mean 15.07 months). Histologically, the follicular type (n=20, 66.7%) constitute the majority, while the clinical types were solid-multicystic (n=18, 60%) and unicystic (n=12, 40%). Enucleation was the treatment of choice in most (n=18, (60%)) of the patients. CONCLUSION: Ameloblastoma is relatively uncommon in children, especially those less than ten years of age. The solid-multicystic variety was the predominant type in the children studied. Most patients presented long after the onset of the tumour and enucleation with mechanical curettage produced satisfactory results in these patients. FUNDING: None declared.

Calcifying cystic odontogenic tumor associated with ameloblastoma - A rare histological variant.

Calcifying odontogenic cysts (COCs) represent a heterogeneous group of lesions that exhibits a variety of clinical, behavioral, and histological features. COC or Gorlin's cyst is now classified by the World Health Organization as a tumor. Calcifying cystic odontogenic tumor (CCOT) is an uncommon developmental odontogenic lesion that demonstrates histopathologic diversity. Odontogenic tumors such as ameloblastoma have been reported to be associated with CCOT. In this paper, we report a case of ameloblastomatous CCOT in a 16-year-old girl with involvement of mandibular posterior region, which is an extremely rare histologic variant.

Treatment of a calcifying epithelial odontogenic tumour with tube decompression: a case report.

Conservative treatment of odontogenic tumours with decompression or marsupialisation is not common, but can be done successfully in those with a cystic pattern. We present a calcifying epithelial odontogenic tumour that was treated by tube decompression and subsequent enucleation.

Calcifying Odontogenic Cyst Associated With Dentigerous Cyst in a 15-Year-Old Girl.

Calcifying odontogenic cyst (COC) is a rare odontogenic cyst with ameloblastic epithelial lining containing clusters of ghost cells. COCs have been described in association with several odontogenic tumors, more commonly odontomas and rarely with dentigerous cyst (DC). In this article, we describe a case of COC associated with DC in a 15-year-old girl, who presented with a swelling on the right middle third of the face, producing facial asymmetry. Panoramic radiography showed a well-circumscribed, corticated, and unilocular radiolucency at the level of the right maxillary sinus, involving 2 unerupted premolars. The lesion was enucleated and histologically revealed a COC associated with DC, which presented mucous metaplasia. Immunohistochemical reactions were performed to better illustrate this rare synchronous occurrence of COC and DC, showing positivity for CK5, CK14, CK19, and p63 in both lesions. CK18 was negative in COC, and Bcl-2 was negative in DC. Periodic acid Schiff highlighted the mucous cells in the DC lining.

A multicentre study of 268 cases of calcifying odontogenic cysts and a literature review.

OBJECTIVES: To investigate the frequency of calcifying odontogenic cysts (COCs) that have been submitted for microscopic examination from representative geographic regions of Brazil and to compare it with literature data. MATERIALS AND METHODS: A retrospective study was conducted on biopsies obtained from 1953 to 2016 at 10 Brazilian oral and maxillofacial pathology centres. A total of 198,350 biopsy specimens were analysed. Demographic data and histopathological diagnosis were evaluated descriptively and statistically. In addition, a literature review of case series was carried out in four electronic databases. RESULTS: A total of 268 cases of COC were surveyed, representing 0.1% of the oral lesions at the centres studied. Female patients in their second decade of life and the maxilla were more affected. The mean lesion size of symptomatic individuals was larger than that of cases without symptoms (p = 0.026). The literature review showed a higher frequency in Asia and Europe, mainly affecting men in the third decade of life. CONCLUSIONS: COC is a rare lesion. Novel data on the clinicopathological features of 268 cases have been added to the literature. Data regarding gender and age of the Brazilian patients reported herein contrast with findings of case series and retrospective studies reported elsewhere.

Peripheral Developing Odontoma or Peripheral Ameloblastic Fibro-Odontoma Erupting to Oral Cavity Case Report / Odontoma en Desarrollo Periférico o Fibro-Odontoma Ameloblástico Periférico Eruptando a Cavidad Oral Reporte de Caso

ABSTRACT: The appearance of mixed odontogenic tumors into the oral cavity is a rare event. It is considered that some mixed tumors are only a stage in the complete development of a hamartomatous formation such as ameloblastic fibroodontoma and odontoma. Both pathologies share in common cellular elements which at one point makes them indistinguishable from each other. We present the case of a 21 year old patient who showed a mandibular growth whose histological elements present characteristics of both pathologies. The treatment was surgical excision of the lesion. There were no complications or recurrences to periodic reevaluation.

RESUMEN: La aparición de tumores odontogénicos mixtos en la cavidad oral es un evento raro. Se considera que algunos tumores mixtos son solo una etapa en el desarrollo completo de una formación hamartomatosa como el fibro-odontoma ameloblástico y odontoma. Ambas patologías comparten elementos celulares comunes que en un punto los hacen indistinguibles entre sí. Presentamos el caso de un paciente de 21 años que mostró un crecimiento mandibular cuyos elementos histológicos presentan características de ambas patologías. El tratamiento fue la escisión quirúrgica de la lesión. No hubo complicaciones o recurrencias a la reevaluación periódica.

A lesion categorized between ghost cell odontogenic carcinoma and dentinogenic ghost cell tumor with CTNNB1 mutation.

Ghost cell odontogenic carcinoma (GCOC) is a rare malignant neoplasm characterized by the presence of ghost cells. It is considered to arise either de novo or from a preexisting benign precursor, calcifying odontogenic cyst (COC), or dentinogenic ghost cell tumor (DGCT). We report a case of a 44-year-old Japanese male with a left maxillary tumor. The patient received treatment to resect the left maxillary cyst 25 years prior; however, the details were uncertain. The tumor was resected with clear margins. Taken together with the results of histological and immunohistochemical examinations, the tumor was categorized between GCOC and DGCT, and we diagnosed the tumor as GCOC suggesting similarity to DGCT. Further, we focused on CTNNB1, which encodes ß-catenin and is frequently mutated in COCs. In this tumor, we identified CTNNB1 Ser33Cys, one of the mutations typically found in COCs. This finding suggests that CTNNB1 is a common target for the pathogenesis of tumors accompanied by ghost cells.

Calcifying epithelial odontogenic cyst.

OBJECTIVE: The Calcifying Odontogenic Cyst was first described as a distinct clinicopathologic entity by Gorlin and his colleagues in 1962. Gold (1963) chose a similar, but not identical term for the lesion, namely 'keratinizing and calcifying odontogenic cyst'. The calcifying cystic odontogenic tumor (CCOT) is a new designation of calcifying odontogenic cyst (COC) recommended by the 2005 classification of the World Health Organization (WHO). The calcifying odontogenic cyst is not a common lesion; the dentinogenic ghost cell tumor is even less common and should be considered rare. The lesions have in common the peculiar abnormal keratinization of odontogenic and metrical (hair) epithelial cells that is termed 'ghost cell' or 'shadow cell' keratinization. A rare, well-circumscribed, solid or cystic lesion derived from odontogenic epithelium that resembles follicular ameloblastoma but contains 'ghost cells' and spherical calcifications. The so-called calcifying odontogenic cyst (COC) represents a heterogeneous group of lesions that exhibit a variety of clinicopathologic and behavioural features. Because of this diversity, there has been confusion and disagreement on the terminology and classification of these lesions. Here we present a classic case of Calcifying Odontogenic Cyst (COC) or Calcifying Cystic Odontogenic Tumor in a 37 years old male patient. which is provisionally diagnosed by means of clinical & radiographical findings and later on confirmed by histological examination.