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

Comparative Analysis Between Dentinogenic Ghost Cell Tumor and Ghost Cell Odontogenic Carcinoma: A Systematic Review

Dentinogenic ghost cell tumor (DGCT) and ghost cell odontogenic carcinoma (GCOC) form a spectrum of rare benign and malignant odontogenic neoplasms, respectively. The aim of this study was to perform a comparative systematic review of the clinicopathological, genetic, therapeutic, and prognostic features of DGCT and GCOC. The electronic search was performed until December 2020 on seven electronic databases. Case reports, series, and research studies with enough histopathological criteria for diagnosis and all genomic studies were included. Both DGCT and GCOC showed a male prevalence (p = 0.043), with mandibular and maxillary predilections, respectively (p = 0.008). Peripheral DGCT (DGCTp) affected most elderly people (p < 0.001), and central DGCT (DGCTc) and GCOC occurred mainly in younger individuals. Unilateral enlargement of maxilla or mandible was the most common clinical sign associated with a radiolucent or mixed image. Ameloblastomatous epithelium was often present in both neoplasms. Basaloid and large cells with vesicular nuclei were also frequently seen in GCOC. β-catenin expression and mutations (CTNNB1 gene) were found in DGCT and GCOC. Conservative surgery was mostly used for DGCTp, while radical resection was chosen for DGCTc and GCOC. High recurrence rates were found in DGCTc and GCOC. Metastasis occurred in 16.7% of GCOC cases and the 5-year survival rate was 72.6%. DGCT and GCOC share numerous clinicopathological features and demand a careful histopathological evaluation, considering the overlap features with other odontogenic tumors and the possibility of malignant transformation of DGCT. A strict regular post-operative follow-up is mandatory due to high recurrence rates and metastatic capacity in GCOC.

Intraosseous carcinoma of the jaws: a clinicopathologic review. Part II: Odontogenic carcinomas

This is the second of a 3-part review of the clinicopathologic features of intraosseous carcinoma of the jaws (IOCJ). This part deals with odontogenic carcinomas, rare entities that are difficult to evaluate because of changes in classification/nomenclature, lack of standardized diagnostic criteria, and variable consistency of the existing literature. Endorsing a critical approach, problems are addressed and areas of uncertainty are highlighted. As in part I, we emphasize histopathologic features from a diagnostic point of view and also question the existence of some "distinct" entities.

Immunohistochemical analysis of p53 and PCNA expression in calcifying odontogenic cyst

Calcifying odontogenic cyst (COC) is a developmental odontogenic cyst in the jaw. Because of its diverse histopathologic features and biological behavior, there has long been confusion with regard to its nature as a cyst or neoplasm. This study evaluated the proliferative activity of 57 COC samples, including simple cyst (10 cases), cystic neoplasm (34 cases), solid neoplasm (6 cases) and combined lesion (7 cases) by p53 and PCNA immunohistochemical staining. For assessment of p53 and PCNA positivity, the number of positively stained cells with brown-stained nuclei was counted in 1000 cells from each sample. p53 and PCNA expression in the solid neoplasm subtype were significantly higher when compared to cystic neoplasm and simple cyst (P < 0.05). The lowest p53 and PCNA expression was found in the simple cyst subtype. p53 and PCNA expression in the basal and suprabasal layers was significantly higher in the solid subtype when compared to others, and the difference between COC groups was significant. The results demonstrated that within benign types of COC, the amount of p53 and PCNA in proliferative epithelium is significantly higher when compared to non-proliferative epithelium. p53 and PCNA markers are possible parameters for differentiation of COC subtypes.

Ghost cell odontogenic carcinoma arising in calcifying odontogenic cyst

A case of exceptionally rare odontogenic malignant tumor, called ghost cell odontogenic carcinoma, is described. The tumor was considered to be derived from calcifying odontogenic cyst, which had been resected 5 years before. In the present resected specimen, cellular atypia, mitotic activity, Ki-67 labeling index, and p53 positivity were all increased in comparison with the initially resected specimen. This is a valuable case in which malignant transformation from calcifying odontogenic cyst to ghost cell odontogenic carcinoma was proven by the histopathologic and immunohistochemical findings. Pathologists should be aware of this rare entity.

A pigmented calcifying cystic odontogenic tumor associated with compound odontoma: a case report and review of literature

Background

Pigmented intraosseous odontogenic lesions are rare with only 47 reported cases in the English literature. Among them, pigmented calcifying cystic odontogenic tumor, formerly known as calcifying odontogenic cyst, is the most common lesion with 20 reported cases.

Methods

A case of pigmented calcifying cystic odontogenic tumor associated with odontoma occurring at the mandibular canine-premolar region of a young Japanese boy is presented with radiographic, and histological findings. Special staining, electron microscopic study and immunohistochemical staining were also done to characterize the pigmentation.

Results

The pigments in the lesion were confirmed to be melanin by Masson-Fontana staining and by transmission electron microscopy. The presence of dendritic melanocytes within the lesion was also demonstrated by S-100 immunostaining.

Conclusion

The present case report of pigmented calcifying cystic odontogenic tumor associated with odontoma features a comprehensive study on melanin and melanocytes, including histochemical, immunohistochemical and transmission electron microscopic findings.

Molecular pathology of odontogenic tumors

Odontogenic tumors are lesions derived from the elements of the tooth-forming apparatus and are found exclusively within the jawbones. This review represents a contemporary outline of our current understanding of the molecular and genetic alterations associated with the development and progression of odontogenic tumors, including oncogenes, tumor-suppressor genes, oncoviruses, growth factors, telomerase, cell cycle regulators, apoptosis-related factors, regulators of tooth development, hard tissue-related proteins, cell adhesion molecules, matrix-degrading proteinases, angiogenic factors, and osteolytic cytokines. It is hoped that better understanding of related molecular mechanisms will help to predict the course of odontogenic tumors and lead to the development of new therapeutic concepts for their management.

Beta-catenin mutations are frequent in calcifying odontogenic cysts, but rare in ameloblastomas

We have reported previously that alterations to beta-catenin occur frequently in adamantinomatous craniopharyngioma. Based on its histological resemblance to some odontogenic tumors, we suspected the presence of common genetic alterations among these tumors. To address this issue, 11 cases of calcifying odontogenic cyst (COC) and 20 cases of ameloblastoma were investigated for the presence of beta-catenin mutations and beta-catenin expression. Ten COCs were successfully analyzed by direct sequencing, and nine of them were found to harbor somatic beta-catenin mutations. Immunohistochemically, all of the COCs showed nuclear and cytoplasmic expression of beta-catenin with a heterogeneous pattern. No beta-catenin mutations were found in ameloblastomas, except for one case of the follicular type. All follicular ameloblastomas exhibited moderate nuclear and cytoplasmic accumulation of beta-catenin, in contrast to the predominantly membranous expression seen in the plexiform type. beta-Catenin mutation is considered to be a characteristic genetic feature of COC, and may play a critical role in its histogenesis. Although ameloblastoma closely resembles COC histologically, the two have genetically distinctive features.

A case of calcifying odontogenic cyst with numerous calcifications: immunohistochemical analysis

The purpose of this study was to investigate a case of calcifying odontogenic cyst (COC) in which numerous calcifications were observed not only in the lining epithelium, but also in the cyst wall, using cytokeratins 13 (CK13), 19 (CK19), and core binding factor a-1 (cbfa-1) as primary antibodies. Cells of Malassez's epithelial rest were stained as controls. Cells of the epithelial nests in the cyst wall were reactive for CK13, but their CK19 staining was similar to that observed in the lining epithelial cells. Calcifying nodules were reactive only for CK13. Cells of Malassez's epithelial rest were reactive for CK19 but not for CK13. Cbfa-1 positive reactivity was observed only in nuclei of spindle cells in the periodontal ligament. CK13 was positive superficial to the prickle cells. CK19 was positive in the basal cells of the oral mucosa. In the lining epithelium of the cyst, the expressions of CK13 and CK19 were similar to their immunoreactions in the oral mucosa. These results suggest that the odontogenic epithelium differentiated into squamous epithelial cells, which began as ghost cells in the COC, and that this process depended on the dystrophic calcification of differentiated odontogenic epithelial cells, not of osteogenic cells.

Calcifying odontogenic cyst: clinicopathological features and immunohistochemical profile of 10 cases

BACKGROUND

Calcifying odontogenic cyst (COC) is an uncommon odontogenic lesion with few studies describing its immunohistochemical profile and proliferative activity reported in the literature.

METHODS

Clinical and histological features and immunohistochemical expression of cytokeratins, Mel-CAM (CD146), bcl-2, PCNA and ki-67, in 10 cases of COC were studied.

RESULTS

All 10 cases affected the maxilla, eight intraosseous and two peripheral. Five central cases were cystic and three were cystic associated with odontoma, and the two extraosseous showed solid histological pattern; immunohistochemistry was positive for cytokeratins 8, 14, 19, AE1/AE3 and 34betaE12 and bcl-2 in all cases, and Mel-CAM in six cases. Proliferative activity was greater in the epithelium of central cystic COC in relation to COC associated with odontoma and peripheral lesions.

CONCLUSION

Calcifying odontogenic cysts showed odontogenic cytokeratin profile and bcl-2 and Mel-CAM expression indicate that these proteins may be involved in the development of COC. There were no recurrences after surgery, irrespective of their proliferative activity.

Peripheral calcifying odontogenic cyst

BACKGROUND

Calcifying odontogenic cyst (COC) is a rare lesion representing about 1% of jaw cysts. It may occur in a central (intraosseous) or peripheral (extraosseous) location.

METHOD

A case of peripheral COC located on the gingiva, appearing as a painless, circumscribed, pink nodule has been reported.

RESULTS

Peripheral, in contrast to central, COC tends to affect older patients. Peripheral COC is a less aggressive lesion than the central counterpart, and a simple excision biopsy is curative.

CONCLUSION

The histological finding of a keratinized epithelium rich in ghost cells has helped in making the diagnosis.