p53 expression and mutation analysis of odontogenic cysts with and without dysplasia

Odontogenic Keratocyst With Moderate Epithelial Dysplasia: A Rare Entity

We present a rare case of odontogenic keratocyst (OKC) with moderate epithelial dysplasia in a 47-year-old male patient. He presented with a history of pain and swelling on the right side of his face for the past three months. The radiograph revealed multi-locular radiolucency involving the ramus, coronoid process, and condylar process of the right mandible. We have discussed the cytology, incisional biopsy, radiological investigations, surgical management, reconstruction, excisional biopsy report, and follow-up of this rare entity.

Cyst or Tumor? A systematic review and meta-analysis on the expression of p53 marker in Odontogenic Keratocysts

The odontogenic keratocyst (OKC) is a potentially aggressive odontogenic lesion and there is an ongoing debate regarding its biological behavior and classification. The present systematic review aims to assess the expression of the p53 protein in the odontogenic keratocyst in comparison to the dentigerous cyst and ameloblastoma. We searched MEDLINE, Web of Science and Scopus for immunohistochemical studies reporting OKC's, dentigerous cysts and solid/multicystic ameloblastomas. The Risk Difference between the lesions expressing the p53 was the effect measure and a P value < 0.05 was considered to provide evidence to the effect estimates. Results: The first hit retrieved 126 records. After duplicates removal, there were 84 articles, of which eighteen were assessed for eligibility. Thirteen articles were included in the meta-analysis, showing that OKC's have an estimated difference of 23% (P < 0.003) in the probability to express the p53 over dentigerous cysts, and an estimated difference of 4% (P = 0.28) in the probability to express the p53 over ameloblastomas. OKCs seem to behave more similarly to a tumor rather than an odontogenic cyst regarding its p53 expression and the classification of this lesion into Keratocystic Odontogenic Tumor should be carefully revaluated.

Orthokeratinized odontogenic cyst: A large series and comprehensive literature review with emphasis on synchronous multiple occurrence and neoplastic transformation

OBJECTIVES

The objective of this study was to demonstrate the clinical, radiologic, and histologic features of orthokeratinized odontogenic cyst (OOC); determine the characteristics of multiple OOCs; and present rare but significant manifestations of OOC.

STUDY DESIGN

A clinical, radiologic, and histopathologic study of 65 primary and 2 recurrent OOC cases was performed retrospectively along with a comprehensive literature review.

RESULTS

OOCs shared similar radiologic findings with odontogenic keratocyst, yet some showed features that have not been previously described: root resorption and radiopaque foci. Histologic review revealed a unique histiocytic lining and some findings suggestive of the multipotentiality of the odontogenic epithelium. The analysis of patients with multiple OOCs demonstrated that multiple OOCs occurred synchronously with a marked predilection for young male adults. Two unusual cases were also identified: an OOC combined with a BRAF^V600E ameloblastoma and a recurrent OOC with malignant transformation.

CONCLUSIONS

This largest series presents previously unreported radiographic and histopathologic features that can be seen in OOC. Multiple OOCs have clinical characteristics distinct from those of solitary cases. The first reported OOC associated with ameloblastoma suggests the involvement of oncogenic mutations in odontogenic tumorigenesis. Although OOC shows a low recurrence rate, the possibility of malignant transformation of recurrent OOCs should be emphasized.

Immunohistochemical profile of the anti-apoptosis, apoptosis and proliferation markers Bcl-2, caspase-3, p53, and Ki-67 in botryoid odontogenic cysts compared to lateral periodontal cysts and gingival cysts of the adult

We investigated the differences in growth and rates of recurrence of the botryoid odontogenic cyst (BOC) and the less aggressive lateral periodontal cyst (LPC) and gingival cyst of the adult (GCA). We compared the immunohistochemical expression of selected biomarkers of apoptosis and proliferation and of regulators of their activity. Sections from archival paraffin blocks of 15 BOCs, six GCAs, six LPCs, and three odontogenic keratocysts (OKCs) were processed for immunohistochemical localization of Bcl-2, caspase-3, p53 and Ki-67. Labeled and unlabeled epithelial cells were counted and differences in the mean labeling index (LI) were evaluated statistically. The only significant differences in LI were for the anti-apoptotic marker, Bcl-2; the hierarchy was BOC > OKC > LPC > GCA. In two BOCs, 97% of the cells, and in all OKCs, all of the basal cells were labeled with Bcl-2. Otherwise, cells labeled with Bcl-2, p53 and caspase-3 were scattered among the basal and intermediate epithelial cell layers. Ki-67 labeled almost exclusively basal cells in the BOCs, LPCs and GCAs, and both basal and intermediate layer cells in the OKCs. Our findings suggest that while there was no significant difference in replicative potential of the GCAs, LPCs and BOCs, factors that influence apoptosis may be partially responsible for the more aggressive behavior of BOCs and OKCs.

Orthokeratinized odontogenic cysts: a Spanish tertiary care centre study based on HPV DNA detection

Background

The role of human papillomavirus (HPV) in orthokeratinized odontogenic cysts (OOCs) has rarely been studied. The objective is to describe the clinicopathological findings in a series of OOCs from a Spanish population that were investigated in relation to the possible presence of HPV.

Methods

A clinicopathological retrospective analysis followed by a molecular analysis of 28 high- and low-risk HPV genotypes was performed in OOC samples of patients seen during the last 15-years in a Spanish tertiary care center.

Results

Of 115 odontogenic cysts with keratinization, 16 cases of OOCs were confirmed and evaluated. OOCs occurred predominantly in the mandible of males (mean age 36.06 ± 13.16 years). Swelling of the jaw followed by pain were the most common clinical symptoms, and 56.5% of the OOC cases were associated with an unerupted tooth. After a mean post-cystectomy follow-up of 3.8 years, only one recurrent case was observed, resulting in a verrucous cystic lesion that was considered premalignant after immunohistological examination. DNA extraction was successful from 14 of the 16 OOC cases. None of the primary OCCs or the single recurrent OOC were positive for HPV in the molecular analysis.

Conclusions

OOCs show a very limited potential for recurrence. Our results suggest that neither high- or low-risk HPV subtypes are likely to play a role in the etiology or neoplastic transformation of OOC, at least in the Spanish population.

Malignant changes developing from odontogenic cysts: A systematic review

The aim of this study was to systematically review scientific literature in orderto describe the characteristics and prognosis of malignant entities developing from odontogenic cysts. A search in Pubmed (MEDLINE) and Cochrane databases was conducted. The inclusion criteria were articles published in English related to the malignisation of odontogenic cysts in humans. The exclusion criteria were articles that do not specify the type of odontogenic cyst, malignisation of parakeratinised keratocysts, the presence of an ameloblastic carcinoma and metastasis from distant primary tumours. The selected articles were classified according to Strength of Recommendation Taxonomy criteria. Statistical analysis of the data was carried out using statistical package software SPSS version 22.0. From the 1,237 articles initially obtained, the authors included 3 case series and 45 case reports in the end. Descriptive analysis showed that men have a disposition for malignisation from odontogenic cysts and they frequently appear at the posterior mandible, with pain and swelling being the most frequent signs and symptoms. Follicular cysts were the entities that underwent the most malignant changes with well differentiated squamous cell carcinomas being the most prevalent type of malignancy. The real prognosis of this malignancy is not known because of the heterogeneity of available studies.

Key words:Odontogenic cysts, squamous cell carcinoma, neoplastic cell transformation, oral cancer.

Primary intraosseous squamous cell carcinoma arising in an odontogenic keratocyst previously treated with marsupialization: case report and immunohistochemical study

A rare case of primary intraosseous squamous cell carcinoma arising in an odontogenic keratocyst (OKC) is presented here, with the clinical and histologic features of the first biopsy showing characteristics of OKC and the second biopsy disclosing a squamous cell carcinoma. Immunoprofile of this case was compared with five cases of classical OKC by using cytokeratins CK5, CK14, and CK19, CD138, p63, Ki-67, p53, and bcl-2. Classic OKCs showed expected positivity, mainly in the basal and/or suprabasal layers with most antibodies, except for p53, which was negative, whereas the present case showed irregular positivity in all layers, indicating that this can be useful for differential diagnosis and suggesting a possible role in malignant transformation into primary intraosseous squamous cell carcinoma. In conclusion, immunohistochemical differences between the first biopsy of the present case and classic OKC suggest that immunohistochemistry can be helpful in cases with areas of subtle initial malignant transformation.

Evidence for loss of heterozygosity (LOH) at chromosomes 9p and 17p in oral granular cell tumors: a pilot study

OBJECTIVE

The objective of this study was to assess loss of heterozygosity (LOH) in tumor suppressor gene loci in oral granular cell tumors (GCTs).

STUDY DESIGN

We assessed LOH in 8 samples of oral GCT using polymorphic microsatellite markers at chromosome regions 3p, 9p, 11q, and 17p, flanking areas close to tumor suppressor genes. We further performed immunohistochemistry to detect the p53 and Ki-67 proteins and associated these expressions with the molecular results.

RESULTS

Five samples showed LOH in 3 markers at chromosomes 9p and 17p (markers P53, AFM238WF2 and D9S162) with fraction of allelic loss of 42.8% for each of these markers. No LOH was identified in any other chromosome. LOH was not associated with the immunohistochemical expression of p53 and Ki-67.

CONCLUSIONS

The present study shows LOH at chromosomes 9p and 17p in oral GCTs.