Peripheral calcifying cystic odontogenic tumour and peripheral dentinogenic ghost cell tumour: an updated systematic review of 117 cases reported in the literature.

PURPOSE: To integrate the available data published on peripheral calcifying cystic odontogenic tumour (CCOT) and peripheral dentinogenic ghost cell tumour (DGCT) into a comprehensive analysis of its clinical and radiologic features. METHODS: An electronic search was undertaken in May, 2016. Eligibility criteria included publications reporting cases of peripheral CCOTs/DGCTs having enough clinical, radiological and histological information to confirm a definite diagnosis. Demographic data, lesion site and size, treatment approach and recurrence were analyzed. RESULTS: Hundred and thirty-eight lesions were found (65 publications), and 117 lesions (63 publications) with enough information were analyzed (55 CCOTs, 50 DGCTs, 12 unknown). Mean age of patients was 51.3 ± 23.4 (min-max, 1-92), with higher mean age for the DGCTs variant. The lesions were more prevalent in the mandible, anterior region of the jaws, and in the second, sixth and eighth decades, with an equal sexual distribution. About 20% of all lesions showed signs of erosion of the underlying bone, with a higher rate for DGCTs. The mean lesion size was 1.3 ± 0.8 (min-max, 0.4-3.0). Time of follow-up was informed for 37 lesions, with a mean ± SD of 30.2 ± 21.0 months (min-max, 6-84). Almost all lesions were treated by conservative surgery; only three recurrences were reported. CONCLUSIONS: Peripheral CCOTs/DGCTs are rare lesions. Most of the lesions were treated by simple excision with or without curettage of the underlying bone. As the recurrence rate is very low, a conservative approach seems to be enough for the great majority of cases.

Calcifying odontogenic cyst: dilemma in classification.

Calcifying odontogenic cyst (COC) shows extreme diversity in its clinical and histopathological features, as well as in its biological behavior. Because of this diversity, there has been confusion and disagreement on the terminology and classification of this lesion. Attempts to classify COC can be divided into two concepts: monistic and dualistic. We present a case of COC with coexisting histopathologic features of a cyst and a neoplasm, thus posing a dilemma in the terminology used to categorize and classify it.

A 44-year analysis of ghost cell odontogenic tumour subtypes in an Iranian population.

The objectives of our study were to evaluate the relative frequency of calcifying cystic odontogenic tumours (CCOTs), dentinogenic ghost cell tumours (DGCTs) and ghost cell odontogenic carcinomas (GCOCs), collectively known as ghost cell odontogenic tumours (GCOTs), in an Iranian population and to classify these lesions according to the 2005 WHO guidelines. Clinical/demographic data were recorded for all COCs referred to our Department from 1966 to 2010. H&E-stained slides were re-evaluated by two observers and all cases were reclassified according to the 2005 WHO guidelines. The male to female ratio of 37 retrieved COCs was 1.6 with most cases occurring intraosseously and in the second decade of life. Involvement of the mandible was significantly higher than the maxilla (P = 0.033). Histopathologically, most lesions demonstrated a cystic morphology and there were no GCOCs among our cases. Eight cases were followed for 4-20 years and 3 of them showed a total of 5 recurrences. Considering the variations among clinicopathologic reports of COC from different countries, presentation of epidemiologic data based on a universally accepted classification system would be extremely helpful in providing a better understanding of this lesion and comparing results between studies.

Thirty years clinicopathological study of 60 calcifying cystic odontogenic tumors in Iranian population.

AIM: To reevaluate all cases previously diagnosed as calcifying odontogenic cyst (COC) from the archives of the Department of Oral Pathology at Mashhad Faculty of Dentistry from 1978 to 2008. MATERIALS AND METHODS: Clinical histories and microscopic slides of all cases diagnosed as COC were reviewed and analyzed statistically. The information about patients such as age, sex, clinical features, radiographic view and other necessary data was gathered from biopsy files. RESULTS: The majority of cases occurred in mandible and four cases were peripherally. Thirteen cases were associated with other odontogenic tumors and 11 cases were odontoma type. In two cases, recurrence was reported after surgical treatment which underwent malignant transformation. CONCLUSION: Calcifying cystic odontogenic tumor (CCOT) in Iranian population occurs in younger age group with slightly male predilection and more mandibular, unicystic and simple type. CLINICAL SIGNIFICANCE: It is better to address the noncystic CCOT lesions with their specific terms in order to make histopathological characteristics clear.

Histopathologic diversity of Gorlin's cyst: a study of four cases and review of literature.

AIM: The purpose of the present article is to discuss four different case reports of the so-called calcifying odontogenic cyst and highlight the histopathological diversity of the same. BACKGROUND: Calcifying odontogenic cyst was first described by Gorlin et al in 1962. Ever since, its identification as a specific odontogenic lesion, controversies and confusions have existed regarding the relationship between cystic lesions and solid tumor masses that share cellular and histomorphologic features. Although several classifications were proposed, dilemma still persists regarding the nature of these lesions as cysts, neoplasms and even malignancies. CONCLUSION AND CLINICAL SIGNIFICANCE: The classifications discussed for the so-called calcifying odontogenic cyst by various authors have only added to further confusion rather than enlightening. Though many authors state that classifications remain only an academic exercise, it definitely has significance in treatment planning. Emphasis should, therefore, be laid on a universally accepted classification.

[Benign epithelial odontogenic tumors]. / Benigne epitheliale odontogene Tumoren.

The group of benign epithelial odontogenic tumors consists of the four member types of the ameloblastoma family (solid/multicystic, extraosseous/peripheral, desmoplastic, unicystic), squamous odontogenic tumors, calcifying odontogenic tumors, adenomatoid odontogenic tumors, and keratocystic odontogenic tumors, the former "keratocysts" that were recently reclassified by the World Health Organization and are now regarded as tumors. The latter are by far the most frequent tumors in this group, followed by solid/multicystic ameloblastoma. Although the etiology of these lesions is still unknown, a close relationship to normal tooth development is obvious, which is partially imitated by some tumors. Despite some similarities to each other, at least in part, the biological behavior of these lesions is quite different, as are treatment modalities. The diagnosis is essentially based on localization (intraosseous vs. extraosseous/peripheral) and histology, whereupon the correlation of histological findings with radiographic morphology may be of additional diagnostic value. Because of the range of variation, immunohistochemical investigations are not helpful in diagnosing a particular case.

[Odontogenic cysts]. / Odontogene Kieferzysten.

Odontogenic cysts form a group of diseases whose origin is linked to the persistence of epithelium resulting from the complex embryonic development of the teeth and jaws within the connective tissue. Inflammatory reactions of the surrounding area of the persisting odontogenic epithelium accompany epithelium proliferation, which leads to the development of a gradually expanding cavity that supersedes the surrounding structure. The correlation between activity of the inflammatory reaction and the development of the epithelial proliferation results in a relatively broad variation of histological features of the cyst wall. Since classification of cyst forms depends on their topographical features, clinical information on the classification of variations is urgently needed. For the classification of their clinical course of development and, in particular, in order to differentiate them from cystic odontogenic tumors of the jaw region, a histological examination of cyst wall tissue is necessary, all the more so since the development of a carcinoma deriving from the odontogenic epithelium has only been described in very few cases.

International collaborative study on ghost cell odontogenic tumours: calcifying cystic odontogenic tumour, dentinogenic ghost cell tumour and ghost cell odontogenic carcinoma.

BACKGROUND: Calcifying odontogenic cyst was described first by Gorlin et al. in 1962; since then several hundreds of cases had been reported. In 1981, Praetorius et al. proposed a widely used classification. Afterwards, several authors proposed different classifications and discussed its neoplastic potential. The 2005 WHO Classification of Odontogenic Tumours re-named this entity as calcifying cystic odontogenic tumour (CCOT) and defined the clinico-pathological features of the ghost cell odontogenic tumours, the CCOT, the dentinogenic ghost cell tumour (DGCT) and the ghost cell odontogenic carcinoma (GCOC). METHODS: The aim of this paper was to review the clinical-pathological features of 122 CCOT, DGCT and GCOC cases retrieved from the files of the oral pathology laboratories from 14 institutions in Mexico, South Africa, Denmark, the USA, Brazil, Guatemala and Peru. It attempts to clarify and to group the clinico-pathological features of the analysed cases and to propose an objective, comprehensive and useful classification under the 2005 WHO classification guidelines. RESULTS: CCOT cases were divided into four sub-types: (i) simple cystic; (ii) odontoma associated; (iii) ameloblastomatous proliferating; and (iv) CCOT associated with benign odontogenic tumours other than odontomas. DGCT was separated into a central aggressive DGCT and a peripheral non-aggressive counterpart. For GCOC, three variants were identified. The first reported cases of a recurrent peripheral CCOT and a multiple synchronous, CCOT are included. CONCLUSIONS: Our results suggest that ghost cell odontogenic tumours comprise a heterogeneous group of neoplasms which need further studies to define more precisely their biological behaviour.

Cistos odontogênicos: estudo epidemiológico de 72 casos / Odontogenic cystis: epidemiological study of 72 cases

Introdução: os cistos odontogênicos constituem uma importante doença oral e maxilo-facial. Embora alguns possam resultar da inclusão de epitélio na linha de fusão de processos embrionários, muitos são limitados por epit[elio de origem odontogênica. Podem ser classificados em cistos de desenvolvimento e inflamatórios, de acordo com sua origem. Pacientes e método: os autores realizaram um estudo retrospectivo da incidência de cistos odontogênicos em pacientes atendidos no ambulatório do Serviço de Cabeça e Pescoço do Centro de Oncologia (CEON) do Hospital Universitário Oswaldo Cruz (HUCC)e registrados no Centro Integrado de Anatomia Patológica (CIAP), no período de janeiro de 1980 a janeiro de 2000. No presente estudo, 72 pacientes portadores de cistos odontogênicos foram arrolados. Foram analisados os indicadores tipo histopatológico, gênero, localização topográfica e faixa etária. Resultados: usando a classificação preconizada pela Organização Mundial da Saúde, 54,1% foram cistos dentígeros; 4,1% cisto odontogênico calcificante; 2,8% ceratocistos odontogênicos e 36,2% foram cistos de origem odontogênica, todavia, não identificados quanto ao tipo histopatológico. A maior parte das lesões císticas foi encontrada na maxila (61,1%). Conclusão: o conhecimento de sua origem e achados clinico-patológicos dessas lesões sáo aspectos básicos para realizar um diagnóstico precoce e um tratamento apropriado.

Introduction: the odontogenic cysts are an important oral and maxillofacial disease. Some cysts can be the result of epithelial inclusion into the fusion line of embryonic process. Howrever, others are limited by epithelium of odontogenic origin. They can be classified in developmental and inflammatory cysts according to their origin. Patients and methods: the authors performed the retrospective study of the incidence of odontogenic cysts in patients from the Service of Head and Neck Surgery, Centro de Oncologia (CEON), Hospital Universitário Oswaldo Cruz (HUOC) and registered in Centro Integrado de Anatomia Patológica (CIAP) from January, 1980 to January, 2000. A total of 72 patients with odontogenic cysts were enrolled in this study. The histopathologic type, gender, topographic place and age were analyzed. Results: according to the WHO classification, our findings were as following: dental cysts, 54.1%; calcified odontogenic cysts, 4.1%; apical periodontal cysts, 2.8%; odontogenic ceratocysts, 2.8%; and odontogenic cysts without histophatologic identification, 36.2%. Most part of the cystic lesions were found in the maxilla (61.1%). Conclusion: the knowledge of the origin and the clinic-pathological findings are important aspects in order to perform early diagnosis and adequate treatment.

Ameloblastomatous Gorlin's cyst.

The calcifying odontogenic cyst (COC), first described by Gorlin et al. in 1962, represents a heterogeneous group of lesions that exhibit a variety of clinicopathologic and behavioral features. COC has been categorized under two basic groups namely, cystic and neoplastic. Even after several classifications and sub-classifications, COC remains an enigma. Very few cases of ameloblastomatous COC have been reported in the literature. In this report, we present a case of ameloblastomatous COC / Gorlin's cyst, emphasizing on the rarity of the lesion and distinguishing it from ameloblastomatous ex COC pictographically.

Ameloblastoma ex calcifying odontogenic cyst (dentinogenic ghost cell tumor).

Calcifying odontogenic cyst (COC) has shown to be of extensive diversity in its clinical and histopathological features, as well as in its biological behavior. In this report, a rare case is described of ameloblastoma ex COC (dentinogenic ghost cell tumor) and the relevant literature is briefly reviewed.

[The nature of calcifying odontogenic cysts of the jaws].

OBJECTIVE: To clarify the clinicopathological and behavioral spectrum of the so-called calcifying odontogenic cysts (COC). METHODS: Retrospective analysis of 21 cases previously diagnosed as COC was undertaken to evaluate their clinical, radiographic, pathological and behavioral features. RESULTS: The lesions of this series were divided into three groups, including simple cysts, benign and malignant tumors. The cyst group was composed of 16 cases (9 men, 7 women). The age of the patients peaked at the second decade, with a predilection for the premolar region of the jaws. The clinicopathological features of this group were consistent with that of developmental odontogenic cysts. Follow-up of the 13 patients treated by enucleation revealed no recurrence. The benign tumor group consisted of 4 cases with variable clinicopathologic features. Two cases were solid tumors containing ameloblastomatous epithelium, ghost cells and calcification foci. The other two cases had lesions that contained typical areas of COC and other types of odontogenic tumors (1 ameloblastoma and 1 odontogenic fibromyxoma). All the 4 cases occurred in the mandible with a relative large size. Two of which had a history of multiple recurrences. Only one case was identified as malignant tumor based on its infiltrative growth pattern and histological features. CONCLUSIONS: The so-called COC, previously recognized as a pathologic entity, can show extreme diversity in its clinical and histopathological features as well as in its biological behavior. Thus, the subgroups as simple cyst, benign and malignant tumors should be clarified and treated accordingly. Their terminology and classification should be reconsidered.

Calcifying odontogenic cyst. Report of two cases.

Calcifying odontogenic cyst(COC) is an uncommon developmental odontogenic cyst and was first described by Gorlin in 1962. It is considered as extremely rare and accounts for only 1% of the jaw cysts reported. Here, we present two cases of which one occurred in a 32 year old female with a swelling in the lower anterior region crossing the midline and another in a 29 year old male with a swelling in the upper anterior region without crossing the midline. The radiograph revealed a well circumscribed radiolucency in the first case and with some specks of opacities in the second case. It was not associated with any missing or impacted tooth. Histopathological examination was done with Hematoxylin and Eosin and in addition it was studied immunohistochemically for cytokeratin. The Classical histological features of lining epithelium in the form of cords, presence of ghost cells and some amount of dentinoid tissue were seen. The nature of COC is controversial. Here we have discussed the controversies regarding COC as well as the various proposed classifications for this lesion. Based on the histopathological findings, the diagnosis was confirmed as calcifying odontogenic cyst. These cases are presented here for its rarity.

Proliferative activity of calcifying odontogenic cysts as evaluated by proliferating cell nuclear antigen labeling index.

The calcifying odontogenic cyst (COC) presents with diverse histological features; thus, several subclassifications have been proposed. To evaluate the significance of the various histological features and subtypes of COC from the perspective of proliferative activity, the proliferating cell nuclear antigen (PCNA) labeling index (LI; the percentage of positive nuclei) was assessed immunohistochemically in 25 cases of COC (21 benign and four malignant). All of the benign cases were of the cystic variety and further subclassified into non-proliferative subtype (NPS; four cases); proliferative subtype (PS; eight cases); and COC associated with odontoma (COCaO, nine cases). The PCNA LI of the malignant COC (65.2+/-5.6) was significantly higher than that of the benign COC (11.6+/-9.0; P = 0.002). Non-proliferative subtype (6.8+/-2.8) showed the lowest PCNA LI and PS (17.2+/-11.2) the highest of among the three subtypes of benign cystic COC (P = 0.028). In nine cases of COCaO, six showed epithelial lining of the non-proliferative type as NPS and the other three had lining with proliferative features as PS. The PCNA LI of the latter COCaO group (14.3+/-6.6) was significantly higher than that of the former (6.1+/-4.3; P = 0.05), as seen between PS and NPS. These results demonstrate that PCNA LI is a possible parameter for differentiating malignant COC from benign COC and, whatever the subtypes, the proliferative features in the lining are the main factor influencing the proliferating activity of COC.

So-called calcifying odontogenic cyst: review and discussion on the terminology and classification.

The so-called calcifying odontogenic cyst (COC) shows extensive diversity in its clinico-histopathological appearances and biological behaviour. Because of this diversity, there has been confusion and disagreement on the terminology and classification of this lesion. The attempts at classification of COC may be divided into two concepts. The first concept is the "monistic" one that all COCs are neoplastic in nature, even though the majority are cystic in architecture and appear to be non-neoplastic. The second is the "dualistic" concept that COC contains two entities: a cyst and a neoplasm. Although the World Health Organization (WHO) classified COC as an odontogenic tumour in 1992 based on the former concept, current thinking favors strongly the latter one. In this article, several previous classifications of COC in the literature are discussed and a new simple classification scheme based on the "dualistic" concept is proposed.

Odontogenic classification of craniopharyngiomas: a clinicopathological study of 54 cases.

Based on the striking histological similarity of craniopharyngiomas and some odontogenic tumours, we reclassified a series of 54 craniopharyngiomas (52 adamantinomatous and two papillary variants) according to the WHO classification of odontogenic tumours. Twenty-seven tumours (50%) corresponded histologically to calcifying odontogenic cyst. 13 tumours (24%) to ameloblastoma, and eight (15%) tumours showed features of both calcifying odontogenic cyst and ameloblastoma either within the same specimen or in specimens derived from different resections. Rare tumours included three cases resembling calcifying epithelial odontogenic tumour and one case resembling adenomatoid odontogenic tumour. No odontogenic counterpart could be established for papillary craniopharyngiomas. The two major subtypes, i.e. craniopharyngioma corresponding to calcifying odontogenic cyst and craniopharyngioma corresponding to ameloblastoma, did not differ in their basic clinical features. Our data confirm and extend the close histological resemblance between adamantinomatous craniopharyngioma and odontogenic tumours and cysts. Furthermore, although calcifying odontogenic cyst and ameloblastoma arising in the jaw differ in clinical presentation and outcome, our study did not reveal clinical differences for the corresponding subtypes of craniopharyngioma.