Calcifying ghost cell odontogenic tumor (CGCOT) with predominance of clear cells: a case report with important diagnostic considerations

Ghost cells unveiled: A comprehensive review

BACKGROUND

Ghost cells (GCs) are cells with distinct intracytoplasmic keratinization, which leads to the preservation of the cellular outline with a clear area corresponding to the previous nucleus location. GCs may show various patterns, such as degeneration, tissue granulation, and calcification. Their true nature and the mechanism regulating the conversion of odontogenic epithelial cells into GCs remain unclear. GC keratinization is different from normal keratinization as they are larger than keratotic squames, are frequently vacuolated, and have prominent nuclear membrane remnants. Few cystic lesions, odontogenic tumors, and non-odontogenic tumors, such as calcifying odontogenic cyst, craniopharyngioma, pilomatrixoma, odontoma, dentinogenic ghost cell tumor, and ghost cell odontogenic carcinoma, exhibit GCs as a typical feature. The Wnt and Notch signaling pathways play a role in the histogenesis of the neoplasms.

HIGHLIGHT

The review clarifies the various proposed hypotheses of the histogenesis of GCs, including molecular pathogenesis. Diagnostic workup for the identification of GCs, including special staining and immunohistochemistry, has been extensively discussed. A stepwise algorithm for identifying odontogenic and non-odontogenic lesions containing GCs has been proposed. Additionally, the prognostic role of GCs in the lesions has been elucidated.

CONCLUSION

Among the various hypotheses of the origin of GCs, we suggest that aberrant keratinization is the most accepted based on various immunohistochemical studies and special staining characteristics. GCs are a distinct characteristic entity of many odontogenic and non-odontogenic lesions; however, it remains controversial whether their presence has any pathognomonic role in the biological nature of these lesions.

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.

Calcifying Odontogenic Cyst with Extensive Areas of Dentinoid: Uncommon Case Report and Update of Main Findings

The calcifying odontogenic cyst (COC) is a benign odontogenic cyst that occurs in the gnathic bones. This cyst is part of a spectrum of lesions characterized by odontogenic epithelium containing “ghost cells,” which may undergo calcification. Areas of an eosinophilic matrix material compatible dentinoid also may present adjacent to the epithelial component. However, these areas of dentinoid commonly do not appear so abundant in COCs. In this study, we report a case of intraosseous COC with extensive areas of dentinoid and perform an update regarding the clinical, radiographical, histopathological, and differential diagnosis, treatment, and prognosis of this cystic lesion.