Cytokeratin 19 expression patterns of dentigerous cysts and odontogenic keratocysts

Pediatric Oral Pathology: Odontogenic Cysts

Cysts encountered in the head and neck typically arise from epithelium that would normally be programmed to form teeth or tooth-supporting structures (odontogenic epithelium). These cysts come with a confusing array of similar-sounding names and histopathologic features that are sometimes shared between conditions. Here we describe and contrast the relatively-common lesions: hyperplastic dental follicle, dentigerous cyst, radicular cyst, buccal bifurcation cyst, odontogenic keratocyst, glandular odontogenic cyst, and the less-common gingival cyst of the new-born and thyroglossal duct cyst. The goal of this review is to help clarify and simplify these lesions for the general pathologist, pediatric pathologist, and surgeon.

Immunohistochemical Characterization of Reactive Epithelial Changes in Odontogenic Keratocysts

Odontogenic keratocysts (OKCs) have a diagnostic thin epithelial lining characterised by a linear epithelial connective tissue interface generally lacking inflammatory changes, basal palisading of the nuclei and a wavy parakeratotic layer on the surface. This typical epithelium may convert to a thicker non-keratinizing one with rete pegs and a relatively flat surface after operative decompression. The aim was to characterize this type of epithelial change by immunohistochemistry for bcl2, keratin17, 10 and 19. Eleven out of 33 archived OKCs demonstrated an altered epithelium related to previous biopsy, decompressing drainage or inflammation. The typical basal bcl2 staining was lost in 10/11 cases; transepithelial CK17 was lost or markedly reduced in 9/11 cases. CK10 displayed a segmental upper layer staining in OKCs, and its loss or partial loss in the altered epithelium did not differ from negative areas of OKCs. CK19 displayed various staining patterns in the altered epithelium from lost to maintained in a patchy transepithelial distribution, the latter of which did not differ from the typical OKC staining pattern. Three of four non-keratinizing epithelial linings with basal palisading displayed immunostaining reminiscent of typical OKC epithelium. The lack of a typical epithelium is not sufficient to exclude the diagnosis of OKC if the sampling is not generous (e.g. biopsy), and the presence of non-keratinizing epithelium with basal palisading and an immunophenotype characteristic of OKC (basal bcl2, patchy or diffuse CK17 and upper layer CK10 positivity) may be consistent with the OKC diagnosis even in the absence of typical epithelial lining.

Cytokeratin and fibronectin expression in orthokeratinized odontogenic cyst: A comparative immunohistochemical study

Background

The orthokeratinized odontogenic cyst (OOC) is a rare developmental jaw cyst. It is crucial to distinguish it from keratocystic odontogenic tumor (KCOT) in all parameters including clinical behavior, immunohistochemical (IHC) profile and prognosis. This study aimed to analyze the IHC expression of cytokeratins and fibronectin in OOC, epidermoid cyst and dermoid cyst (EDC/DMC), dentigerous cyst (DC) and KCOT in order to explicate the pathogenesis of OOC.

Materials and Methods

Twenty-five cases of all study groups were incubated with CK10, CK13, CK19 and fibronectin antibodies and staining was assessed in the basal, intermediate and surface layers of epithelium. All the data were analyzed by SPSS software. Nonparametric Chi-square test and Spearman's correlation test were applied.

Results

The overall expression pattern of CK10, CK13 and CK19 was similar and resembled each other in the study groups of OOC and EDC. The immunoexpression was almost akin to each other in DC and KCOT.

Conclusion

It was inferred from the results that the IHC profile of OOC is different from DC and KCOT and closer to EDC.

The importance of ctokeratins in the early detection of oral squamous cell carcinoma

Background

Oral cancer is usually diagnosed at advanced stages. The pattern of keratin expression in normal epithelia and the change in their expression in premalignant lesions and carcinomas have suggested the possibilities of improving diagnosis. The aim of this study is to determine the use of acidic cytokeratins (CKs) as biomarkers of histopathological progression in oral carcinogenesis.

Materials and Methods

A total of 50 paraffin blocks of histological specimens diagnosed as hyperplastic epithelium, dysplastic epithelium, well-differentiated squamous cell carcinoma (SCC) and poorly-differentiated SCC (10 specimens each) were included in this study, in addition to 10 normal oral mucosal samples. All samples were stained immunohistochemically with CKs (10-ab1, 14, 16-ab1, 18-dc10 and 19-abs10) using Ventana Medical Systems (Arizona-USA). The expression of CKs antigen was evaluated as absent, mild, moderate and severe.

Results

CK10-ab1 was found to be positive in the suprabasal layers of all specimens in normal and hyperplastic epithelium, while it was moderate in dysplastic epithelium and mild in well-differentiated SCC. CK10-ab1 was negative in all samples with poorly-differentiated SCC (P < 0.005). CK14 was positive in all specimens of all groups whereas CK16-ab1 was negative in all specimens of all groups. The stain of CKs 18-dc10 and 19-abs10 was restricted to the basal cells only in normal, hyperplastic and dysplastic epithelium, while it was mild in well-differentiated and poorly-differentiated SCC (P < 0.01).

Conclusion

CK10-ab1 disappeared gradually with the progression of malignant changes of squamous cells whereas CKs 18-dc10 and 19-abs10 increased gradually at the same time. Such changes in the protein mapping of squamous cells need more investigation for a better understanding of oral SCC.

A Comparative Analysis of Cytokeratin 18 and 19 Expressions in Odontogenic Keratocyst, Dentigerous Cyst and Radicular Cyst with a Review of Literature

INTRODUCTION

Odontogenic cysts viz Odontogenic Keratocyst (OKC), Dentigerous Cyst (DC) and Radicular Cyst (RC) occur commonly in the oral and maxillofacial region. Cytokeratin (CK) expression studies have been done to evaluate diagnostic accuracy, role in pathogenesis, elucidate behaviour and role in treatment protocols. However, variations have been reported in the expression of CK patterns in these odontogenic cysts, which could be due to the lack of standardization of laboratory techniques. The present study has tried to shed light on CK 18 and 19 expression in odontogenic cysts and offer the brief review of previous studies on these CK.

AIM

The aim of the present study was to evaluate the intensity and expression patterns of CK 18 and 19 in OKCs, DCs and RCs.

MATERIALS AND METHODS

A total of 60 cases, 20 each of OKC, DC and RC were confirmed histologically and evaluated for immunohistochemical expression pattern and intensity of CK 18 and 19.

RESULTS

A focal and variable expression of CK 18 was observed in 25% of OKCs, 15% of DCs and 10% of RCs. CK 19 was expressed in 75% of OKCs and 100% in DCs as well as RCs.

CONCLUSION

The intensity and expression of Cytokeratin 19 was more in all three cysts compared to Cytokeratin 18.