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, Prætorius 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.     

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.     

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.     

Ghost cell characterization in calcifying odontogenic cysts and dentinogenic ghost cell tumors: An immunohistochemical study

ObjectivesThe aim of our study was to ascertain the true nature of ghost cells (GCs) by immunolocalization of cytokeratin (CK) 6, CK19, and amelogenin in calcifying odontogenic cysts (COCs) and dentinogenic ghost cell tumors (DGCTs) in an attempt to determine the nature of this unique cell.MethodsA total of thirteen cases (six COCs and seven DGCTs) were examined immunohistochemically, in order to compare immunoreactivity for CK6, CK19, and amelogenin in odontogenic GCs.ResultsPositive expression of amelogenin (92.3%) and CK6 (77%) was chiefly found in GCs. CK19 expression was observed in the cytoplasm of odontogenic epithelial cells of the lining epithelium. GCs were devoid of CK19 expression and were positive only on the cytoplasmic periphery.ConclusionIn the current study, GCs showed accumulation of amelogenin and hard keratins in their cytoplasm during pathological transformation.     

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

Toida M: So-called calcifying odontogenic cyst: review and discussion on the terminology and classification. J Oral Pathol Med 1998; 27: 49–52. © Munks-gaard, 1998.
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.     

Central odontogenic fibroma: An updated systematic review of cases reported in the literature with emphasis on recurrence influencing factors

Purpose

To integrate the available data published on central odontogenic fibroma (COF) into a comprehensive analysis of its clinical/radiologic/histological features.

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.     

Squamous odontogenic tumor and squamous odontogenic tumor-like proliferations in odontogenic cysts: An updated analysis of 170 cases reported in the literature

Purpose

To integrate the available data published on squamous odontogenic tumors (SOT) and squamous odontogenic tumor-like proliferations in odontogenic cysts (SOT-LPOC) into a comprehensive analysis of their clinical/radiologic features.

Glandular odontogenic cyst (sialo-odontogenic cyst): report of two cases and literature review of 45 previously reported cases

The clinical, radiological, histopathological and immunohistochemical (cytokeratin) features of two cases of glandular odontogenic cyst (GOC) are presented and discussed in a review of 45 cases of GOC hitherto reported. Of cases with available information, 34 occurred in the mandible and 6 in the maxilla; the male:female ratio was 19:28, and the mean age was 46.7 years in males and 50.0 years in females. Six cysts recurred once after 2-8 years (mean 2 years 8 months) and 2 (5.3%) recurred twice after 2 and 5 years and after 3 and 5 years, respectively, giving a rate of recurrence of 21%. The identification of osteodentin in one of the present cases and the co-expression of cytokeratins (CK) 13, 19 and 8 strongly support the concept of odontogenic differentiation in the GOC. Careful surgical removal of the lesion succeeded by a 5-year follow-up period is recommended.     

Desmoplastic ameloblastoma: a systematic review of the cases reported in the literature

The aim of this study was to integrate the available data published on desmoplastic ameloblastoma (DA) into a comprehensive analysis of its clinical/radiographic features. As it is not clear whether the hybrid ameloblastoma has a unique biological behaviour, the clinical/radiographic features of conventional DA were compared with those of the hybrid variant. An electronic search was undertaken in May 2019. Eligibility criteria included publications with sufficient clinical/radiographic/histological information to confirm the diagnosis. A total of 128 publications reporting 285 DAs were included (246 central non-hybrid, 33 central hybrid, 6 peripheral). There was a statistically significant difference between non-hybrid and hybrid cases concerning lesion location, radiographic limits, and size. In contrast to non-hybrid tumours, which showed a similar distribution in the mandible and maxilla, hybrid tumours showed a high predominance of mandible location. Non-hybrid lesions more often showed ill-defined radiographic margins, and were smaller tumours than hybrid DAs. Enucleation with an additional therapy (either curettage or peripheral osteotomy) or resection led to a lower recurrence risk in comparison to curettage or enucleation without additional therapy. The location of the lesion and type of treatment are related to tumour recurrence. There are important differences in location and radiographic limits between hybrid and non-hybrid DAs, which support their classification as distinct lesions.     

Odontogenic ghost cell carcinoma: report of four new cases and review of the literature

Only 12 odontogenic ghost cell carcinomas (OGCC) have been reported in the English language literature to date. This article reports four additional cases of this rare odontogenic tumour and examines them in relation to those previously described. Judging from the number of published cases, the OGCC is more prevalent in Asians than other racial groups, occurs more often in the maxilla than the mandible, and is slightly more common in males than females. Histologically, elements of a benign calcifying odontogenic cyst (COC) can be identified in all the malignant variants, either separated or admixed with the malignant epithelial component. The latter can consist of either small basaloid cells or large epithelial cells. Despite the differing histological presentations, the biological behavior of the tumour is unpredictable, with some cases characterized by relatively indolent growth and others by a locally aggressive and potentially fatal course. The tumour apparently arises most often from malignant transformation of a preexisting benign COC, although it may also develop from other odontogenic tumours.     

Gingival cyst of the adult,lateral periodontal cyst,and botryoid odontogenic cyst: An updated systematic review

The aim of the present review was to integrate the available data published on gingival cyst of the adult (GCA), lateral periodontal cyst (LPC), and botryoid odontogenic cyst (BOC) into a comprehensive analysis of their clinical/radiological features. An electronic search was undertaken in July/2017. Eligibility criteria included publications having enough clinical/radiological/histological information to confirm the diagnosis. A total of 146 publications (157 GCAs, 213 LPCs, 96 BOCs) were included. GCA and LPC presented highest prevalence in the sixth/fifth decades; BOC in the sixth/seventh decades. LPCs were larger lesions than GCAs and GCAs appeared at an older age than LPC. There was no statistically significant difference between them for other factors (location, symptoms, recurrence, follow‐up time). In comparison with LPC, BOC lesions were larger, appeared more often in mandible and in older subjects, had more often a multilocular appearance, and presented a higher recurrence rate. Recurrence rates: GCA (3.2%), LPC (2.4%), BOC (21.7%). No factor seems to influence the recurrence rate of GCA or LPC. Multilocular radiological appearance seems to affect the recurrence rate of BOCs. Conservative surgical approaches seem to be enough for GCA/LPC. BOC presents a more aggressive behavior than GCA/LPC. Therefore, treatment of this lesion might involve some kind of adjunctive therapy after enucleation.     

Central calcifying epithelial odontogenic tumour in the posterior maxilla: a case report

The calcifying epithelial odontogenic tumour (CEOT), or Pindborg tumour, is a rare, benign odontogenic tumour. CEOT is usually asymptomatic and an incidental radiological finding, often presenting as a mandibular radiolucency with flecks of calcific material. We report an unusual case of CEOT in the left posterior maxilla of a 46‐year‐old male that was associated with an unerupted tooth. The tumour in this case caused non‐specific sinus symptoms and appeared radiographically similar to an odontoma or ossifying fibroma due to its dense calcific contents. Diagnosis was confirmed histologically following surgical removal of the lesion, which showed classic CEOT histomorphology. We report this case to highlight the unusual clinico‐radiologic presentation and illustrate the diagnostic difficulties that can occur with radiolucent and/or radiopaque lesions in the jaws.     

Synchronous gubernacular canals with compound odontoma associated with a calcifying odontogenic cyst and transmigrated canine: An extremely rare event

This article reports the novel incidental concurrences of multiple oral lesions in a 13-year-old boy. Radiographically, an over-retained primary canine was seen with a subjacent mixed radiopacity and transmigrated permanent canine with a suspected dentigerous cyst (each with gubernacular canals). Treatment consisted of enucleation and removal of the impacted canine. The histopathologic findings were compound odontoma containing multiple tooth-like structures and calcifying odontogenic cyst with epithelium containing ghost cells, calcifications and subjacent fibrous connective tissue wall. All cases of odontomas should undergo microscopic assessment for diagnosis and ascertainment of associated pathosis.     

A recurrent case of odontogenic ghost cell tumour of the mandible

Odontogenic ghost cell tumour (OGCT), also referred to as dentinogenic ghost cell tumour, is an extremely rare tumour classified as a neoplastic variant of calcifying ondontogenic cyst (COC). To date, only 13 cases of OGCT arising in the maxilla or mandible have been reported. We describe an OGCT that recurred after segmental resection of the mandible in a 59-year-old man. Histopathological examination revealed tumour invasion of the surrounding cortical bone, areas containing numerous calcifying flaky cell nests, and dentinoid matrix near epithelial cell nests. No atypical mitosis was found. There has been no evidence of recurrence or metastasis in the 4 years after operation.