Keratocystic odontogenic tumors: predictive factors of recurrence by Ki-67 and AgNOR labelling

Immunohistochemical Analysis of Dentigerous Cysts and Odontogenic Keratocysts Associated with Impacted Third Molars-A Systematic Review

OBJECTIVE

This systematic review investigates the diagnostic, prognostic, and therapeutic implications of immunohistochemical markers in dentigerous cysts (DCs) and odontogenic keratocysts (OKCs) associated with impacted third molars.

MATERIALS AND METHODS

A comprehensive search strategy was employed across major databases including MEDLINE/PubMed, EMBASE, and Web of Science, from the inception of the databases to March 2024. Keywords and Medical Subject Heading (MeSH) terms such as "dentigerous cysts", "odontogenic keratocysts", "immunohistochemistry", "Ki-67", and "p53" were used. The PRISMA 2020 guidelines were followed to ensure methodological rigor. Inclusion criteria encompassed studies on humans and animals providing definitive diagnoses or specific signs and symptoms related to DCs and OKCs, with results on protein expression derived from immunohistochemistry, immune antibody, proteomics, or protein expression methods.

RESULTS

Of the 159 studies initially identified, 138 met the inclusion criteria. Our analysis highlighted significantly higher expressions of Ki-67 (22.1% ± 4.7 vs. 10.5% ± 3.2, p < 0.001), p53 (15.3% ± 3.6 vs. 5.2% ± 1.9, p < 0.001), and Bcl-2 (18.4% ± 3.2 vs. 8.7% ± 2.4, p < 0.001) in OKCs compared to DCs, indicating a higher proliferative index, increased cellular stress, and enhanced anti-apoptotic mechanisms in OKCs. Additionally, PCNA levels were higher in OKCs (25.6% ± 4.5 vs. 12.3% ± 3.1, p < 0.001). Genetic mutations, particularly in the PTCH1 gene, were frequently observed in OKCs, underscoring their aggressive behavior and potential malignancy.

CONCLUSIONS

The findings emphasize the significant role of immunohistochemical markers in distinguishing between DCs and OKCs, with elevated levels of Ki-67, p53, Bcl-2, and PCNA in OKCs suggesting a higher potential for growth and recurrence. Genetic insights, including PTCH1 mutations, further support the need for personalized treatment approaches. These markers enhance diagnostic accuracy and inform targeted therapeutic strategies, potentially transforming patient management in oral and maxillofacial surgery.

Evaluation of the relationship between the expression of AgNOR and Ki67 with the recurrence rate in central granulomatous giant cell lesions: A case-control

OBJECTIVES

Giant cell granuloma is a local nonneoplastic lesion that is divided into two categories, based on its site of occurrence: Central and peripheral giant cell granuloma. Central giant cell granuloma is an intraosseous lesion that has a tendency to recure even in surgically treated cases. Several studies have proven that there is an association between different lesions clinical behavior and their histological features. The aim of this study was to evaluate the expression of AgNOR and Ki67 in lesions with and without recurrency.

MATERIAL AND METHODS

Files and records of 35 patients who had been histologically diagnosed with central giant cell granuloma were investigated. Histological features were studied after performing AgNOR staining and Ki67 marker. The data were analyzed by chi-square, Fisher, and T-test.

RESULTS

Acquired data indicated that the count of AgNOR staining and Ki67 marker was significantly higher in lesions with recurrency than the lesions with no recurrency. The same results were attained from Ki67 intensity.

CONCLUSION

The current study indicated that AgNOR staining and Ki67 marker have prognostic value in predicting recurrency of central giant cell granuloma lesions.

Expression of anti - Apoptotic survivin in odontogenic keratocyst, adenomatoid odontogenic tumor and ameloblastoma

Background

The process of odontogenesis is complex involving epithelial-mesenchymal interactions, along with the molecular signalling pathways triggering the initiating process. The triggering factors and cells precisely involved in the pathogenesis of odontogenic cysts and tumors are unknown. There is a vast array of biomarkers used to stain different sites, thereby helpful in diagnosing and evaluating the prognosis of these cysts and tumors. In the following study, Anti Apoptotic survivin expression patterns were assessed quantitatively in 48 samples (12 each) of Reduced Enamel Epithelium, Adenomatoid Odontogenic Tumor, Odontogenic Keratocyst and Ameloblastoma.

Aim

The Aim of this study is to assess the anti-apoptotic survivin expression in Reduced Enamel Epithelium, Adenomatoid odontogenic tumour, Odontogenic Keratocyst and Ameloblastoma.

Materials and Methods

The present study is carried out with 12 samples in each group. Routine hematoxylin and eosin staining was performed for confirmatory diagnosis. Later Immunohistochemistry was performed using survivin antibody. Survivin protein expression was analyzed using the parameters like location, intensity, percentage of cells positivity with survivin protein and extent of staining. With the help of Olympus BX 43 microscope, with ProgRes microscope camera, the 48 slides obtained were examined. The region of interest was selected in each slide and number of cells positively stained was counted. Data was analyzed using SPSS software version 23. Descriptive for scale data, results were analysed by using ANOVA with Chi-square test for intergroup comparison.

Results

The results showed significant P value <0.05. Expression of survivin was highest in Ameloblastoma, followed by Odontogenic keratocyst, Adenomatoid odontogenic tumor, and Reduced Enamel Epithelium.

Conclusion

Survivin was involved in the inhibition of apoptosis as well as the detailed understanding of the biological behaviour of odontogenic cysts and tumours, thereby increasing therapeutic approaches.

[Techniques for the treatment of keratocyst, review of the literature and case report]

The odontogenic keratocystic tumor (OKT) or also currently known as odontogenic keratocyst (OK) is a benign pathology derived from the remains of the dental lamina characteristic for possessing variable amounts of desquamated keratin. It usually rises as solitary or with the presence of satellite cysts, the appearance of these satellite cysts is frequently related to the possible recurrence of OK, according to the literature, this recurrence can vary between 0 - 50%. As for the treatment stage of (OKT), it can be mentioned that at present there is a well-defined histological and clinical criterion, which facilitates its recognition and therefore its treatment. According to the literature, there are several treatment procedures that can be classified into non-conservative or radical treatments and conservative treatments accompanied by adjuvant methods. Within the non-conservative or radical treatments, we find en bloc resection, which is the most aggressive way to treat a keratocyst; however, it is the most effective way to avoid recurrence. Within the conservative treatments, marsupialization, decompression, and enucleation with or without adjuvant therapy are described. It is paramount to know how to recognize the different types of treatment for (OKT) since this will be conditioned by multiple factors, such as the location of nearby bone structures and the size of the lesion considering the possible involvement of dental structures. The objective is to seek the lowest-risk treatment possible, which avoids recurrence and finally puts an end to this pathology.

Evaluating histopathological factors of predicting the recurrence rate of odontogenic keratocyst

Background

Odontogenic keratocyst (OKC) is one of the most common jaw cysts with high recurrence rate. Some possible factors affecting recurrence that have not been evaluated in previous studies are examined in this study. This study aimed to predict the recurrence rate of OKC and more viable treatment of OKC.

Materials and Methods

In this descriptive, analytical, and cross-sectional study, 10 recurrent OKCs, which both slides before and after recurrence were accessible, were collected from oral and maxillofacial pathology department's archive. First, they were evaluated based on common histopathologic features. In the second phase, the frequency of these findings in 36 OKCs (24 samples with recurrence and 12 without recurrence after 5 years) was evaluated based on clinical, radiological, and histopathologic features. Data were analyzed by SPSS, Wilcoxon signed-rank test, McNamara, t-test, Chi-square, Mann-Whitney, Fisher's exact test, Cohen's kappa coefficient, and odds ratio (P < 0/05).

Results

According to this study, OKC in women, with multilocular radiolucency and mitosis in basal layer of epithelium as well as diffused inflammation, were statistically associated with probability of recurrence (P = 0.05, 0.035, 0.033, and 0.045, respectively). The corrugated surface, reverse polarity, hypercellularity in parabasal, and satellite cysts can affect the recurrence of OKC with odds ratios = 2.364, 2.364, 1.190, and 1.500, respectively).

Conclusion

Gender (women), multilocular radiolucency, diffused inflammation in stroma, and mitosis in basal layer of epithelial lining, can statically predict the possibility of recurrence rate. In addition, findings regarding the age (in younger patients), corrugated surface, reverse polarity, and sub-basal cleft can be helpful in predicting recurrence.

Effectiveness of different treatments for odontogenic keratocyst: a network meta-analysis

Odontogenic keratocysts (OKC) are benign but aggressive lesions. As there is a lack of well randomized clinical studies assessing the effectiveness of the different treatment options for OKC, a network meta-analysis (NMA) was performed to identify the best treatment option with the lowest recurrence rate. An electronic search was performed following the PRISMA guidelines to identify all clinical studies comparing treatment options against enucleation alone. The outcome variable was recurrence. The predictor variables were treatments. The eight included treatments were: enucleation with peripheral ostectomy/curettage (E + PO/curettage); enucleation with cryotherapy (E + CRYO); enucleation with/without PO followed by modified Carnoy's solution (E ± PO+MCS); enucleation with PO and with topical 5-fluorouracil (E + PO+5FU); enucleation with/without PO followed by original Carnoy's solution (E ± PO+CS); marsupialization alone (MARS); marsupialization followed by secondary enucleation with/without PO (MARS+2°E ± PO); and resection. The odds ratio was used to estimate the recurrence rate. A frequentist NMA was performed using Stata software. A total of 2989 patients in 40 studies were included. Both direct pairwise meta-analysis and NMA showed that E + 5FU+PO was significantly superior to E ± PO+MCS. However, no statistically significant difference was found between E ± PO+CS vs E + 5FU+PO, E ± PO+MCS, and resection, respectively (all very low quality evidence). The three most effective treatments in reducing the recurrence rate were E + PO+ 5FU (98.1%; very low quality evidence), resection (83.5%; very low quality evidence), and E ± PO+CS (63.8%; moderate quality evidence). The findings from this study suggest that CS remains the most effective fixative agent after enucleation and PO until proven otherwise. Additionally, 5FU appears to be an effective method with promising results that needs further research. Finally, the efficacy of MCS remains controversial; further in vivo and in vitro studies are required to determine new protocols. As this NMA included retrospective studies, the results should be interpreted with great caution (level of evidence: type III).

An evidence-based surgical algorithm for management of odontogenic keratocyst

The effective management of odontogenic keratocyst (OKC) remains a subject of interest and confusion in the oral and maxillofacial surgery literature. Currently, there is a lack of consensus regarding the most appropriate treatment for patients with OKC. Of the various treatment options available, no modality to date has been shown to demonstrate a zero or near-zero recurrence rates except wide resection with clear margins. With the prevailing dearth of evidence based surgical protocols for the management of patients with OKC in the literature, this study aims to present a surgical algorithm, based on meta-analysis results, that hopefully will be beneficial in enhancing treatment of patients with this condition. Also, new meta-analysis was done to compare between modified Carnoy's solution (MCS) and 5-fluorouracil (5-FU) in respect of recurrence rate of OKC. Using parameters like size, lesion type (primary or secondary), syndromic or solitary nature of the lesion, presence of cortical perforations, and locularity; we present a decision tree, to aid treatment planning and help attain the least chance of recurrence in the management of the OKC. There was very low-quality evidence indicating that application of 5-FU, after enucleation and peripheral ostectomy of OKCs, significantly lowered recurrence rate when compared to MCS (RR = 0.087, CI: 0.017 to 0.436, P value = 0.003).

Novel recurrence risk stratification of odontogenic keratocysts: A systematic review

The aim of this study was to identify all clinical, radiological, histopathological, and immunohistochemical features associated with recurrence of odontogenic keratocysts (OKCs) in the literature and formulate a recurrence risk stratification based on these findings. A search was performed in PubMed/Medline, Scopus, Web of Science, Google Scholar and Cochrane databases for clinical and laboratory studies reporting on clinico-pathological features that led to OKC recurrences for the period 2000 to 2020. Twenty-three studies were identified and analyzed qualitatively. A total of 2064 OKCs were included of which 439 OKCs were recurrent with a mean follow-up period of 46.7 months. Significantly associated parameters with OKC recurrence included age (variable age categories), large (>4 cm), multilocular lesions with cortical perforation, association with dentition, presence of daughter cysts, and epithelial budding. Immunohistochemical markers including high Ki67 index and AgNOR count were also implicated. A recurrence risk stratification was formulated based on these findings. Although the level of evidence from the included studies was low, there was considerable evidence that the clinico-pathological parameters identified were linked with higher OKC recurrence. The surgeon, radiologist, and pathologist should aim to identify these features when making a diagnosis so as to determine the appropriate management regime and prevent recurrences.

Odontogenic keratocyst located in the retromolar trigone

Odontogenic keratocysts (OKCs) are a commonly occurring, benign cystic intraosseous lesion thought to arise from the cell rests of the dental lamina. Most instances of OKC are commonly found in the posterior aspect of the mandible. In rare instances, there have been reported cases of OKCs arising in the peripheral gingiva, but these cases are few and far between. Rarer still are the few documented cases of OKCs arising in other soft tissues of the mouth. There are many divided opinions on the diagnosis of these lesions and whether they are truly odontogenic in origin, given their location when they are enucleated from a soft tissue area. To the best of our knowledge, we present the first reported case of a patient with a peripheral OKC located in the retromolar trigone. We discuss this unique case and review the current literature on peripheral OKCs.

Ki-67 expression as a diagnostic biomarker in odontogenic cysts and tumors: A systematic review and meta-analysis

Ki-67 is a marker of cell proliferation, used as an important diagnostic marker in the pathologic differentiation of various lesions. It is also relevant for developing targeted molecular therapies. We carried out a systematic review to assess the Ki-67 labeling index (LI) in odontogenic cysts and tumors. Databases were searched, including PubMed (MEDLINE), Scopus, CINHAL, PsycoInfo, the Cochrane Library, and Proquest. The meta-analysis was carried out based on the data of 608 lesions. When a 5% cut-off point was set, ki-67 LI of all benign odontogenic tumors dropped below this point. All the malignant tumors demonstrated an LI of over 15.3%; a significantly higher Ki-67 LI in malignant odontogenic lesions (17.59±2.80) was observed. Among benign tumors, the largest and the smallest Ki-67 LIs were seen in ameloblastoma (4.39±0.47) and adenomatoid odontogenic tumor (0.91±1.71). The mean values of Ki-67 LI in tumors and cysts were 4.23 (0.38) and 1.04 (0.07), respectively. Among odontogenic cysts, the highest Ki-67 LI was found in odontogenic keratocyst (OKC) (3.58±0.51), and the lowest in the radicular cyst (1.29±0.62%). Ki-67 LIs in all odontogenic cysts were <3%, except for OKC. This controversial lesion seems to have a profile more similar to a tumor, and a treatment plan similar to tumors might be suggested. We found that odontogenic lesions have diverse proliferative activities that help differentiate between various lesions and suggest therapeutic plans.

Cysts and Pseudocysts of the Oral Cavity: Revision of the Literature and a New Proposed Classification

This article includes a comprehensive and up-to-date review on the cysts of the oral cavity. Several classifications of odontogenic (OC) and non-odontogenic (non-OC) oral cysts and the surrounding regions have been proposed. We suggest a new critical classification based on an established relationship between anatomical area, histological origin and clinical behavior (frequency, rate of recurrence, malignant potential). Moreover, the differential cytokeratin (CKs) expression of the various cysts is reported as epithelium-specific markers of differential diagnosis. Finally, issues related to differential diagnosis and therapeutic approaches of the cysts included in the two groups are described.

Histopathological and immunohistochemical study in keratocystic odontogenic tumors: Predictive factors of recurrence

The aim of the present study was to identify the most useful markers for predicting recurrence of keratocystic odontogenic tumors (KCOTs). A total of 65 tumor samples from 63 patients diagnosed with typical parakeratinized cysts and KCOTs between 1992 and 2014 were retrospectively studied. Clinical and histopathological data and treatment modality were reviewed. In addition, the expression profiles of Ki-67, cluster of differentiation (CD)34 and podoplanin were assessed using immunohistochemistry. The association between these factors and the rate of KCOT recurrence was evaluated. The presence of daughter cysts, epithelial islands and high Ki-67, CD34 and podoplanin expression levels were revealed to be associated with tumor recurrence. In particular, univariate analysis revealed that high CD34 expression levels were significantly associated with tumor recurrence (P=0.034), as was conservative surgical treatment (P=0.003). Multivariate analysis revealed that conservative treatment was the greatest independent risk factor for tumor recurrence (odds ratio=13.337; P=0.018). These results suggest that overexpression of CD34 may be a potent predictor of tumor recurrence and radical treatment of the teeth that are in contact with the tumors is recommended in order to prevent tumor recurrence.

Correlation between ploidy status using flow cytometry and nucleolar organizer regions in benign and malignant epithelial odontogenic tumors

OBJECTIVE

Differentiation between the aggressive benign odontogenic tumors and their malignant counterparts is controversial and difficult. While flow cytometry (FCM) allowed DNA analysis in neoplasia, argyrophilic organizer regions (AgNORs) number and/or size in a nucleus are correlated with the ribosomal gene activity and therefore with cellular proliferation. The aim of this research was to study the diagnostic accuracy of FCM and AgNORs staining in differentiating between benign and malignant epithelial odontogenic tumors and to correlate between these two interventions.

DESIGN

Sixteen benign cases [8 cases of ameloblastoma (AB) and 8 cases of keratocystic odontogenic tumor (KCOT)] and 13 malignant epithelial odontogenic tumors [8 cases of ameloblastic carcinoma (ABC) and 5 cases of clear cell odontogenic carcinoma(CCOC)] were included in the current study. For FCM analysis, a single cell suspension from Formalin fixed paraffin-embedded (FFPE) tumors was prepared according to a modified method described by Hedley (1989) and AgNORs staining were performed in accordance to the Ploton protocol (1986). Analysis of AgNORs was performed using both quantitative and qualitative methods.

RESULTS

The work revealed that all the examined tumors were diploid, except for 40% of CCOC cases. The S-phase fraction (SPF) value, AgNORs count and AgNORs area/cell showed statistically significant difference on comparing benign and malignant groups. A weak positive correlation was observed between SPF and AgNORs count.

CONCLUSION

The SPF value was considered to be more sensitive and specific in differentiation between aggressive benign and malignant epithelial odontogenic tumors in comparison to AgNORs counting.

The role of vascular endothelial growth factor in proliferation of odontogenic cysts and tumors: An immunohistochemical study

Background:

Vascular endothelial growth factor (VEGF) is capable of initiating angiogenesis in blood vessels and may act as mitogenic agent for epithelium of odontogenic cysts and tumors. This study was conducted to evaluate the role of epithelial VEGF expression in odontogenic cysts and ameloblastoma and its correlation with argyrophilic nucleolar organizer region counts to assess its role in their biological behavior.

Materials and Methods:

In this retrospective cross-sectional study, 45 histologically confirmed cases, 15 cases of each of keratocystic odontogenic tumors (KCOTs), dentigerous cysts, and ameloblastomas were examined for immunohistochemical expression for epithelial VEGF, and argyrophilic nucleolar organizer regions (AgNORs) (used as secondary marker in this study) staining was done for comparing the proliferative capacity with VEGF.

Results:

KCOT shows mild expression within the basal layers and strong expression in the suprabasal layer whereas, in dentigerous cysts, a majority showed no VEGF expression whereas ameloblastomas showed strong expression in all cases by stellate reticulum-like cells at the center of the follicles and suprabasal layers of epithelium. The results of AgNOR counts were higher in KCOTs as compared to ameloblastoma and least in dentigerous cysts.

Conclusion:

VEGF expression by the epithelium of odontogenic cysts and tumors may play a role in epithelial proliferation via autocrine mechanism as reflected by increased AgNOR counts. The angiogenic activity via paracrine pathway may be responsible for the difference in growth rate and neoplastic behavior of the lesions.

Ki-67 and p53 expression in solitary sporadic, syndrome associated and recurrent keratocystic odontogenic tumor

BACKGROUND

Ki-67 and p53 are markers expressed in actively proliferating cells, particularly in neoplasms.

OBJECTIVES

(1) To study the proliferative potential of epithelia in Solitary Sporadic, Syndrome-associated and Recurrent Keratocystic odontogenic tumors (KCOTs) using Ki67 and p53 labeling indices (LI). (2) To derive a relationship if any between the expression of these proteins and the biologic behavior of Solitary Sporadic and Syndrome associated KCOTs.

STUDY DESIGN

Thirteen paraffin embedded blocks of KCOTs (Solitary Sporadic, n = 03; Recurrent, n = 03; Syndrome associated, n = 07) were stained immunohistochemically for Ki-67 and p53 and labeling indices were calculated.

STATISTICAL ANALYSIS

Z test with predetermined alpha set at 0.05 was used for the comparison of Ki-67 positivity between the three groups and p53 positivity between the three groups.

RESULTS

Ki-67 labeling indices were: 30% in solitary sporadic; 26% in recurrent; and 32% in syndrome associated KCOTs. p53 labeling indices were: 19% in solitary sporadic; 23% in recurrent; and 21% in syndrome-associated KCOTs. There was no difference seen in the rate of proliferation in the epithelial linings between the three groups. However, in our cases where Ki-67 positivity was seen there was expression of p53. Though not statistically significant a trend was seen, reflecting the loss of balance between the proliferative potential and apoptotic activity.

CONCLUSION

On the basis of proliferative index alone it is not possible to comment on biological behavior of KCOTs associated with syndrome versus those of solitary and recurrent. There is probably a mesenchymal role which needs to be researched.

Non-syndromic and syndromic keratocystic odontogenic tumors: systematic review and meta-analysis of recurrences

BACKGROUND

Keratocystic odontogenic tumors (KCOTs) are locally aggressive benign tumors which occur in the bones of both jaws with a high recurrence rate. The aim of the present study was to define and evaluate the post-treatment recurrence of KCOT lesions in non-syndromic and syndromic patients.

METHODS

A systematic review of the literature and meta-analysis was conducted according to the PRISMA statement. Seven electronic databases were searched from their start up to August 2013 for clinical studies on human patients without limitation to year, language or publication status.

RESULTS

A total of five case series studies with 323 treated KCOT lesions were included in the quantitative synthesis. The recurrence rate of KCOTs for three treatment forms ranged from 7% to 28%. Comparisons among the various treatments suggest that resection or marsupialization might be associated with fewer recurrences. However, high risk of bias and effect imprecision preclude the making of clinical recommendation. Existing evidence regarding nevoid basal cell carcinoma patients was likewise scarce.

CONCLUSIONS

The absence of studies with low risk of bias precludes the making of safe recommendations about the optimal management of KCOTs.