Keratocystic odontogenic tumor: a retrospective analysis of genetic, immunohistochemical and therapeutic features. Proposal of a multicenter clinical survey tool

Can CAPRIN-1 Be Responsible for the Recurrence Potential of Odontogenic Keratocysts?

Objectives

The purpose of this retrospective study is to compare dentigerous cysts and odontogenic keratocysts for cytoplasmic activation/proliferation - associated protein-1 antibodies via immunohistochemical staining to obtain a new perspective about the specific behavioural characteristics of odontogenic keratocysts at the molecular level.

Material and Methods

Forty dentigerous cysts (DC) and forty odontogenic keratocysts (OKC) tissue samples were examined using immunohistochemical staining to detect cytoplasmic activation/proliferation - associated protein-1 (CAPRIN-1) antibodies. Nuclear and/or cytoplasmic staining was evaluated as "positive". Cell staining rate (%) and cell staining intensity were determined, and a staining intensity distribution (SID) score was calculated for each sample. Cases were considered "negative" if they showed no staining for CAPRIN-1 antibodies, thus were given a SID score of zero. According to the SID scores, the expression levels were rated as negative, mild, moderate, or high.

Results

Of 80 samples, 16 that could adversely affect immunohistochemical evaluation were excluded. Ten negative, 21 positive and three negative, 30 positive CAPRIN-1 expressions were observed in DC and OKC groups, respectively. The difference between the negative and positive cases within groups was significant only in the OKC group (P = 0.000). The SID score range and mean were 0 to 160 and 31.1 (SD 35.7) for DC and 0 to 160 and 57.3 (SD 42.3) for OKC groups. CAPRIN-1 expression was significantly higher in the OKC group (P = 0.043).

Conclusions

The molecular basis for increased mitotic activity, high recurrence rates or presence of satellite cysts in odontogenic keratocysts may be attributed to the expression of cytoplasmic activation/proliferation - associated protein-1.

Recurrence of nonsyndromic odontogenic keratocyst after marsupialization and delayed enucleation vs. enucleation alone: a systematic review and meta-analysis

PURPOSE

This study was conducted in order to determine whether marsupialization before definitive enucleation of nonsyndromic odontogenic keratocysts (OKCs) is capable of decreasing the recurrence rate more effectively than just enucleation.

METHODS

We searched MEDLINE, Web of Science, Scopus, and Cochrane Library, until August 5th of 2017 for original studies reporting on the treatment of OKCs with and without previous marsupialization and the related recurrence rate. All records and data were independently assessed, meta-analysis was performed, and the odds ratio of recurrence was the effect measure; P value for the summary effect of < 0.05 was considered statistically significant.

RESULTS

The 748 records retrieved were reduced to 6 studies to be qualitatively assessed and 5 studies were included in the meta-analysis. The overall odds ratio of 0.57 [0.25-1.28] of the pooled values pointed that marsupialization reduced the recurrence rate in comparison to just enucleation; however, the P value showed that there is no strong evidence to support this statement.

CONCLUSIONS

Marsupialization followed by enucleation after 12 to 18 months reduces the recurrence rate, but more studies are necessary to support this statement.

Investigation of clinicopathological parameters and expression of COX-2, bcl-2, PCNA, and p53 in primary and recurrent sporadic odontogenic keratocysts

Objectives

Odontogenic keratocyst (OKC) presents considerable variation in aggressiveness and propensity for recurrence, yet hitherto, no explicit clinicopathological features have been determined to clearly demonstrate the potential for relapse. This retrospective study aims to investigate the prognostic relevance of various clinicopathological features as well as immunoexpression of COX-2, bcl-2, PCNA, and p53 in sporadic OKC.

Materials and methods

Among 41 patients with OKC treated by enucleation, the frequency of recurrence for various clinicopathological features as well as immunoexpression for COX-2, bcl-2, PCNA, and p53 was evaluated.

Results

The mean follow-up was 8.49 years, and recurrences were ascertained in 29.27% of cases. We found significant differences between recurrent and non-recurrent cysts in terms of multilocularity (P = 0.029), cortical perforation (P = 0.001), and lesion size (P < 0.001). Hazard risk for the recurrence was 3.362 (95% CI 1.066–10.598) for multilocular cysts, 7.801 (95% CI 2.1–28.985) for evidence of cortical perforation, and 1.004 (1.002–1.006) for 1 mm² of lesion size on panoramic radiographs. We also found that immunoexpression of PCNA significantly correlates with the radiographic evidence of cortical perforation (P = 0.048) and that there is significant positive correlation between expression of COX-2 and bcl-2 (P = 0.001) as well as significant negative correlation between immunoexpression of COX-2 and age (P = 0.002). None of the other analyzed factors were associated with the recurrence.

Conclusions

Larger size, multilocularity, and cortical perforation in sporadic OKC may be correlated with the relapse.

Clinical relevance

Immunohistochemical analyses of COX-2, bcl-2, PCNA, and p53 lack prognostic utility in sporadic OKC.

Odontogenic keratocyst: The role of the orthodontist in the diagnosis of initial lesions

Odontogenic keratocysts (OKCs) are locally infiltrative odontogenic cysts that are usually diagnosed during routine radiographic examinations. Therefore, it is critical that dental practitioners, in particular orthodontists, recognize and diagnose OKCs to recommend appropriate treatment. This report describes a patient whose OKC was not initially identified during orthodontic pretreatment. In addition, this report discusses the clinical and radiographic features of OKCs, as well as the differential diagnoses of these lesions.

Frequent oncogenic BRAF V600E mutation in odontogenic keratocyst

OBJECTIVES

Odontogenic keratocyst (OKC), also known as keratocystic odontogenic tumor (KCOT), has clinical significance due to its high incidence as well as high recurrence rate after surgical enucleation. Current clinical management for OCK is entirely dependent on surgical approach. While various genetic alterations, such as PTCH1 mutation and loss of heterozygosity in tumor suppressor genes, have been reported, the molecular background of OKC is not well-understood. Although recent identification of BRAF V600E mutation and subsequent activation of mitogen-activated protein kinase (MAPK) pathway in ameloblastoma and odontogenic tumors provide additional options with targeted therapeutics, the molecular background of OKC is not well understood.

MATERIALS AND METHODS

In this study, we examined BRAF V600E mutation from paraffin embedded OKC samples by tumor cell enriched microdissection and TA cloning of amplified DNA. We further examined the relationship between BRAF V600E mutation and clinical parameters.

RESULTS

We found frequent BRAF V600E mutation in OKC (24 of 38 samples, 63.2%). However, BRAF V600E mutational status is not related with clinical indexes such as size, location, and recurrence. In orthokeratinized odontogenic cyst, there is one case of BRAF 600E mutation from 11 samples (9.1%).

CONCLUSION

These results indicate that BRAF V600E mutation occurs in OKCs at a high rate and plays an important role in the pathogenesis of OKCs.

Role of Carnoy's solution in the treatment of keratocystic odontogenic tumor: A systematic review

INTRODUCTION AND OBJECTIVE

The keratocystic odontogenic tumor is a benign but aggressive neoplasm. As enucleation alone obtains high recurrence rates, some adjuvant treatments such as Carnoy's solution have been proposed. The aim of this study is to evaluate the reduction of recurrences with the use of Carnoy's solution as adjuvant in the treatment of keratocystic odontogenic tumors.

MATERIAL AND METHODS

An electronic search in Pubmed (MEDLINE), ScienceDirect and Cochrane databases was conducted with the key words "odontogenic keratocyst", "keratocystic odontogenic tumor", "carnoy's solution", "treatment" and "enucleation". The inclusion criteria were clinical studies using Carnoy's solution as adjuvant for the treatment of keratocystic odontogenic tumors, published in English, including at least 10 patients. Articles with an unclear reporting of the treatment applied, nonhuman studies, case reports and lesions associated to Gorlin-Goltz syndrome were excluded.

RESULTS

All the studies included were case series. The recurrence rate of enucleation ranged from 0% to 58.8%. With the only use of Carnoy's solution as adjuvant treatment to the enucleation, recurrences varied from 0% to 100%. The use of ≥ 2 adjuvant treatments reduced the range between 0% and 7.9%.

CONCLUSIONS

The use of Carnoy's solution as adjuvant therapy for the treatment of keratocystic odontogenic tumor has a grade C recommendation.

Keratocystic odontogenic tumor: A biopsy service's experience with 104 solitary, multiple and recurrent lesions

Background

Keratocystic odontogenic tumor (KCOT) is a clinically significant cystic lesion of odontogenic origin. This study aimed to retrospectively review and describe the clinicopathologic features of KCOT and to objectively compare the clinical and histological features of solitary, multiple and recurrent KCOT in a Saudi Arabian population.

Material and Methods

Biopsy request forms, pathology records and archival materials (all histological slides) of 104 cases of KCOT from 75 patients were retrieved. Demographic and clinical details as well as histological evaluation were analyzed and compared between the 3 groups using chi-squared or Mann-Whitney tests of association as appropriate.

Results

Significant differences were noted in the age of presentation, location and association with impaction between multiple and solitary cases. Histologically, there was a difference in the mitotic count, presence of satellite cysts and proliferating odontogenic epithelium between solitary and multiple lesions. There was no difference between the KCOT that later recurred and solitary lesion which did not recur even when matched clinically for age, sex and location. There were differences when solitary KCOT that later recurred or recurrent KCOT were compared with multiple lesions. Multiple lesions still had more significant proliferative activity parameters than solitary recurrence-related KCOT.

Conclusions

KCOTs in Saudi Arabians are not different from those reported from other parts of the world. Clinical and histological analyses showed multiple KCOT is different from its solitary recurrent or non-recurrent counterparts and has a higher proliferative activity than both. Clinicohistologic features alone cannot wholly explain the behavior of KCOT.

Key words:Descriptive study, keratocystic odontogenic tumor, odontogenic keratocyst, solitary, multiple, recurrent.

Recurrent Keratocystic Odontogenic Tumor After Effective Decompression

Keratocystic odontogenic tumor (KCOT) has potential aggressive and infiltrative behavior. Decompression has been widely preferred for large KCOTs due to safety and lower recurrence rates. However, KCOT is still likely to recur even after effective decompression. Here, we present a rare and interesting case of recurrent KCOT after effective decompression with adjunctive enucleation. Redecompression was then performed again, and the effect was still satisfactory on long-term follow-up.

Molecular Signaling in Benign Odontogenic Neoplasia Pathogenesis

Several molecular pathways have been shown to play critical roles in the pathogenesis of odontogenic tumors. These neoplasms arise from the epithelial or mesenchymal cells of the dental apparatus in the jaw or oral mucosa. Next generation genomic sequencing has identified gene mutations or single nucleotide polymorphisms associated with many of these tumors. In this review, we focus on two of the most common odontogenic tumor subtypes: ameloblastoma and keratocystic odontogenic tumors. We highlight gene expression and protein immunohistological findings and known genetic alterations in the hedgehog, BRAF/Ras/MAPK, epidermal growth factor receptor, Wnt and Akt signaling pathways relevant to these tumors. These various pathways are explored to potentially target odontogenic tumors cells and prevent growth and recurrence of disease. Through an understanding of these signaling pathways and their crosstalk, molecular diagnostics may emerge as well as the ability to exploit identified molecular differences to develop novel molecular therapeutics for the treatment of odontogenic tumors.

Five years follow-up of a keratocyst odontogenic tumor treated by marsupialization and enucleation: A case report and literature review

Odontogenic cysts are considered as nonneoplasic benign lesions. Among the cysts, keratocyst odontogenic tumor (KCOT) is an intra-osseous tumor characterized by parakeratinized stratified squamous epithelium and a potential for aggressive, infiltrative behavior, and for the possibility to develop carcinomas in the lesion wall. Thus, the aim of this study was to describe a clinical case of KCOT in a young patient and discuss the treatment alternatives to solve this case. A 15-year-old male was referred for treatment of a giant lesion in his left side of the mandible. After the biopsy, a diagnostic of KCOT was made, and the following procedures were planned for KCOT treatment. Marsupialization was performed for lesion decompression and consequent lesion size reduction. Afterward, enucleation for complete KCOT removal was performed followed by third mandibular molar extraction. After 5 years, no signs of recurrence were observed. The treatment proposed was efficient in removing the KCOT with minimal surgical morbidity and optimal healing process, and the first and second mandibular molars were preserved with pulp vitality. In conclusion, this treatment protocol was an effective and conservative approach for the management of the KCOT, enabling the reduction of the initial lesion, the preservation of anatomical structures and teeth, allowing quicker return to function. No signs of recurrence after 5 years were observed.

Matrix metalloproteinase expression in keratocystic odontogenic tumors and primary cells

Keratocystic odontogenic tumors (KCOTs) are locally invasive, rapidly proliferating cystic lesions of the jaw. The bone-invasive nature of these tumors has been previously associated with the expression of matrix metalloproteinases (MMPs), which degrade the extracellular matrix. The purpose of this study was to assess the expression and activity of MMPs in primary KCOT cells and tumor tissue.

METHODS

Four independently established KCOT primary cell populations were grown in Dulbecco's modified Eagle medium supplemented with 10% FBS and antibiotics. Primary cells were analyzed by qRT-PCR and immunohistochemistry (IHC), and for secretion of active MMPs. Primary tumor sections were analyzed by IHC.

RESULTS

Of the 18 human MMPs examined, 9 were consistently expressed in primary KCOT cells. MMP-2 and MMP-14 were highly expressed in all KCOT populations, while MMP-1, 3, 11, 12, 16, 17, and 19 were moderately expressed. MMP-3, 11, 12, 16, 17 and 19 were shown to be expressed in KCOTs for the first time. No significant differences in MMPS profiles were found between syndromic (KCOT-3) and non-syndromic cell populations (KCOT-1/2/4). Protein expression of MMP-1, 11, 12, 14 and 16 was confirmed in each KCOT cell populations by IHC. KCOT-3 cells secreted active MMP-2 as determined by a gel zymography assay. Expression of MMP-1, 2, 3, 11, 12, 14, and 16 was confirmed in matching primary KCOT tumor sections representing syndromic and non-syndromic KCOTs.

CONCLUSION

KCOT primary cell populations and tumors express a wide range of MMPs, which likely play a role in the bone-invasive nature of these tumors.