Odontogenic keratocyst: What is in the name?

Unwarranted intrusion of odontogenic cyst into the maxillary antrum

During the early growth phase, every individual is involved in a prolonged series of developmental processes in the maxillofacial region. Formation of cysts associated with such three-dimensional growth of the maxillofacial skeleton as well as deciduous and permanent tooth development. The origin of cystic jaw lesions may be odontogenic or non-odontogenic, developmental, or inflammatory and they are epithelial-lined or non-epithelial-lined cysts in nature. These cysts are considered to be aggressive cysts when they tend to grow rapidly and can cause significant damage to the surrounding bone and tissues if left untreated. Aggressive cystic lesion of the jaw needs special attention in order to prevent recurrences or even worsen and widespread disease. The management of the maxillary sinus requires individualisation based on its clinical and histopathological characteristics. Here, we report a case of an aggressive odontogenic cyst in a 30s-aged female patient in the left maxillary sinus with the literature review.

Multilocular Radiolucent Pathology in the Body and Ramus of the Mandible: A Case Report

Odontogenic keratocyst (OKC), a type of epithelial developmental cyst, is frequently found in the jaw region. It has invasive characteristics such as satellite cysts, rapid progression, and tissue expansion. The OKC often favors the mandibular angle and ascending ramus. OKC symptoms include pain, swelling, displacement or malpositioning of adjacent teeth, and erosion or thinning of the limited or no bucco-lingual cortical expansion. There is radiographic evidence of a distinct, often scalloped, radiolucent lesion with a characteristic "soap bubble" or "honeycomb" appearance. This article reports a female patient, aged 40 years, with the main concern of unilateral pain and swelling of the mandibular left side and the provisional diagnosis of ameloblastoma. After histopathological examination, the final diagnosis of the patient was OKC. This article also includes previously published literature on OKC with differential diagnosis and relevant clinical and radiologic findings of the case.

Long-term investigation of minimally invasive alcohol-based therapy as the treatment of odontogenic keratocyst:A retrospective cohort study

The aim of this study was to evaluate the clinical efficacy of alcohol-based therapy for patients with large odontogenic keratocysts (OKCs). The study was implemented as a retrospective, single-center study. Patients treated with ethanol-based therapy for odontogenic keratocyst were retrospectively evaluated for baseline and postoperative data. The pre- and postoperative clinical situation and the extent of radiographic shrinkage were compared. The event is defined as the achievement of >50% reduction in cyst volume. The cyst reduction rate calculated on panoramic radiographs ranged from 7.4% to 99.9% (mean [standard deviation] 55.3% [27.9%]) and was statistically significant (P < 0.05). Specifically, it has been found that, radiographically, 47.6% of patients achieved >50% reduction in cyst volume within 12 months. The continuous cortical bone was rebuilt, and the cyst cavity was filled with regenerated trabecular bone. The 22 included patients presented with nonclinical problems, had no need for further intervention, and exhibited persistent impaction of the teeth. The results of this study demonstrated that ethanol-based therapy triggered marked radiographic reductions of large OKC, indicating that using this technique is efficient.

Comparison of Five Different Treatment Approaches of Mandibular Keratocystic Odontogenic Keratocyst (OKC): A Retrospective Recurrence Analysis of Clinical and Radiographic Parameters

The odontogenic keratocyst (OKC) is a benign but locally aggressive growing lesion that infiltrates the bone and surrounding tissue. It is characterized by high rates of recurrence along with rapid growth. Different forms of partly successful treatment therapies are reported. The retrospective study at hand examined 114 patients with OKC treated over a period of 20 years. Data extracted includes gender, age, location, previous treatment for the lesion, surgery, outcome, recurrence rate and follow-up. 63.1% of the patients underwent cystectomy, 22.5% by cystectomy and carnoy solution, 7.2% by cystectomy, and curettage, 4.5% by cystostomy and 2.7% by partial resection. In this study, no significant differences could be observed regarding the surgical method. Most recurrences occurred with 91.9% in the mandible with an average size of 5.5 cm2 and increased in women. Within a mean follow-up time of 3.6 years the recurrence rate was 36.9%, on average after 36 months. Recurrences were most frequently diagnosed at the age of 31-50 (43.9%). Despite numerous studies, there is still no unanimous opinion on an effective therapy for OKC. However, precise resection of OKC can be facilitated by preoperative 3D-imaging and virtual planning.

Unraveling the Enigma of Managing a Large Periapical Lesion: A Case Report

This case report documents the diagnosis and successful management of a substantial periapical lesion located in the lower left region of the jaw. The patient presented with clinical symptoms indicative of periapical pathology, and radiographic examination revealed an extensive radiolucent lesion. The chosen treatment approach involved endodontic intervention coupled with surgical decompression, leading to the resolution of the lesion and restoration of oral health. This case underscores the significance of an accurate diagnosis and a multidisciplinary treatment approach in addressing large periapical lesions.

Building Automation Pipeline for Diagnostic Classification of Sporadic Odontogenic Keratocysts and Non-Keratocysts Using Whole-Slide Images

The microscopic diagnostic differentiation of odontogenic cysts from other cysts is intricate and may cause perplexity for both clinicians and pathologists. Of particular interest is the odontogenic keratocyst (OKC), a developmental cyst with unique histopathological and clinical characteristics. Nevertheless, what distinguishes this cyst is its aggressive nature and high tendency for recurrence. Clinicians encounter challenges in dealing with this frequently encountered jaw lesion, as there is no consensus on surgical treatment. Therefore, the accurate and early diagnosis of such cysts will benefit clinicians in terms of treatment management and spare subjects from the mental agony of suffering from aggressive OKCs, which impact their quality of life. The objective of this research is to develop an automated OKC diagnostic system that can function as a decision support tool for pathologists, whether they are working locally or remotely. This system will provide them with additional data and insights to enhance their decision-making abilities. This research aims to provide an automation pipeline to classify whole-slide images of OKCs and non-keratocysts (non-KCs: dentigerous and radicular cysts). OKC diagnosis and prognosis using the histopathological analysis of tissues using whole-slide images (WSIs) with a deep-learning approach is an emerging research area. WSIs have the unique advantage of magnifying tissues with high resolution without losing information. The contribution of this research is a novel, deep-learning-based, and efficient algorithm that reduces the trainable parameters and, in turn, the memory footprint. This is achieved using principal component analysis (PCA) and the ReliefF feature selection algorithm (ReliefF) in a convolutional neural network (CNN) named P-C-ReliefF. The proposed model reduces the trainable parameters compared to standard CNN, achieving 97% classification accuracy.

Immunohistochemical expression of paxillin in ameloblastoma and odontogenic keratocyst: An observational study

Background

Cell adhesion molecules (CAMs) are found on the surface of all cells, where they allow dynamic processes to take place. These include cadherins, integrins, selectins and Immunoglobulin superfamily. Directly associated with β-integrin tails is a multidomain protein known as paxillin. However, CAMs participate in cell-cell and extracellular matrix-cell interactions during histomorphogenesis in the various phases of odontogenesis. Some tumours or cysts like ameloblastoma (AB) or odontogenic keratocyst (OKC) having odontogenic origin show disturbance in the interaction of these CAMs. Hence, the assessment of paxillin expression in AB and OKC was carried out.

Materials and Methods

The present observational study comprised 30 clinically and histologically confirmed cases of AB and OKC. All the slides were stained immunohistochemically using a paxillin antibody.

Results

Upon comparison of staining intensity of paxillin among AB and OKC showed statistically significant result, whereas quantitative staining and final summation showed non-significant result. Gender-wise comparison of paxillin staining intensity, quantitative staining and final summation among OKC showed significant result; however, in AB, staining intensity showed non-significant result, whereas quantitative staining and final summation showed significant result.

Conclusion

Paxillin has the greatest influence on tissue morphogenesis and development. The regulation of cell mobility is aided by the multiple roles that paxillin plays in a range of cells and tissues. However, further studies using a large sample size, along with other molecular analytical methods, may be essential to draw a definite conclusion about the association of paxillin and its exact function in OKC and AB.

Comparative evaluation of podoplanin in odontogenic cysts and tumours to determine their proliferative potential-An immunohistochemical study

Context

Odontogenic cysts and tumours are a wide array of complex pathological entities ranging from mild indolent to aggressive detrimental in nature, which occur as a result of anomalous alterations in normal odontogenesis. Hence, these odontogenic lesions need to be evaluated extensively by using potential immunohistochemical markers.

Aim

To evaluate and compare the expression of podoplanin, a lymphoendothelial IHC marker in odontogenic cysts and odontogenic tumours to determine their proliferative potential.

Settings and Design

All the study samples were retrieved from the archives of the Department of Oral Pathology and Microbiology, PIDS&RC, Hyderabad. The study samples were selected as per the standard histopathological diagnostic criteria and subjected for IHC analysis using podoplanin.

Method and Materials

Seventy paraffin-embedded tissue specimens of OKC, OOC, dentigerous cyst (DC) and ameloblastoma (AM) include study sample, which were stained with podoplanin IHC marker and staining properties were evaluated. All the cases were categorized as high, moderate, weak or negatively reactive on the basis of the composite scoring.

Statistical Analysis Used

Statistical analysis was done using SPSS version 14, and then results were compared by ANOVA post hoc test and Kruskal Wallis Test.

Results

In the comparison of composite scores of OKCs and AM, there was no significant statistical difference.

Conclusion

The present study contributes to the significant association of podoplanin expression with cellular proliferation, cystic expansion and local invasiveness of odontogenic cysts and tumours through cytoskeletal reorganization and cell migration.

[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.

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).

Orthokeratinized versus parakeratinized odontogenic keratocyst: Our institutional experience

Introduction

The odontogenic keratocyst (OKC) is quite unique among odontogenic cysts in its specific histological features and in clinical characteristics. The OKC has two variants orthokeratinized odontogenic cyst (OOC) and parakeratinized odontogenic cyst (POC), and POC is considered to be more aggressive and has a high recurrence rate. Therefore, OKC has generated considerable controversy with regard to its true nature.

Aim

The purpose of this study was to determine the differences between POC and OOC variants of odontogenic cysts on the basis of clinical as well as radiological features.

Materials and Methods

A total of 85 cases were included in the present study. There was a marked difference in the age of occurrence, sex, location and radiological presentation of both these entities.

Results

Our institutional experience suggests that POC is more common than OOC and both the variants were commonly found in males. Most of the cases of POC were found in the third decade of life and most of the cases of OOC were frequently seen in the second, fourth and fifth decades. Mandibular posterior area was frequently occurring in both variants. Left side involvement was seen in maxilla and right side in mandible in both variants. Most of the cases were clinically diagnosed as OKC.

Conclusion

The treatment and prognosis varies in both the variants of OKC, hence such epidemiological studies are helpful to ensure proper treatment for these distinct entities.

Autologous bone marrow aspirate concentrate (BMAC) for treatment of keratocystic odontogenic tumour (KCOT)-a case report

Management of keratocystic odontogenic tumor (KCOT) has always remained a conundrum due to its aggressive behavior, indicating wide resection. Achieving an esthetically and functionally acceptable reconstruction remains a challenge. Herein, we present a novel and less invasive technique for the treatment of KCOT. A 55-year-old female presenting with pain in the lower jaw for the past 3 months was diagnosed with a large KCOT extending from 35 to 47 region. CT images revealed buccal and lingual cortical bone erosion. Management was done in two stages: cyst curettage and chemical cauterization, followed by application of Bone Marrow Aspirate Concentrate (BMAC) with a delay of two months, to increase the thickness of eroded cortical bone. On follow-up at one year, ossification of the defect was observed. BMAC is a cocktail of mesenchymal stromal cells, hematopoietic stem cells, fibroblasts, mononuclear cells, macrophages, endothelial cells, progenitor cells, growth factors and cytokines. BMAC cocktail provide an anti-inflammatory, anti-fibrotic, anti-apoptotic, and immunomodulatory environment. Autologous platelet rich plasma provides various growth factors (TGF-β, PDGF, EGF, HGF, NGF, IGF-1) and cytokines. Addition of PRP in BMAC cocktail enhance the regeneration of tissues, where PRP act as a functional regenerative scaffold for cell integration, proliferation, and differentiation that can expedite macroscale musculoskeletal tissue healing. Autologous BMAC with corticocancellous bone acts as an osteoconductive scaffold capable of regenerating the large bone defect created by the curettage of KCOT.

Sub-epithelial hyalinization, incomplete cystic lining, and corrugated surface could be a predictor of recurrence in Odontogenic Keratocysts

BACKGROUND

Odontogenic Keratocysts (OKCs) are known for their rapid growth and tendency to invade the adjacent tissues. Its high recurrence rate (2.5%-62%) has attracted many kinds of research to identify new parameters to predict recurrence that would enable better treatment outcomes for such patients. The present study aims to correlate Sub-Epithelial Hyalinization (SEH) that has not been explored in an Asian population to date and other histopathologic features of OKC to its recurrence propensity.

MATERIALS & METHODS

A total of 60 OKCs were analyzed for histopathologic correlation of thickness of lining, complete/incomplete lining, corrugated surface, ortho/para keratinization, intercellular edema, reversed polarity, basilar hyperplasia, the palisading arrangement of basal cells, presence/absence of rete pegs, folding of the epithelium, epithelial/connective tissue separation, SEH, basal offshoots, daughter cysts and inflammation with recurrence to arrive at the most significant histologic feature predicting recurrence.

RESULTS

The most significant histologic parameter differentiating recurrent and non-recurrent OKCs was the presence of SEH (p = 0.004), incomplete lining epithelium (p ​= ​0.023), and a corrugated surface (p ​= ​0.049). Several other histologic parameters evaluated did not statistically correlate with recurrence, this can be attributed to the smaller sample size considered in the present study.

CONCLUSION

SEH is a reliable histologic parameter to predict recurrence in OKCs. The presence of SEH is indicative of a higher recurrence potential in OKCs. Evaluation of histological parameters and their correlation with recurrence in OKCs on a larger sample size could validate the results of the current study undertaken and potentially unravel more insights on predicting recurrence.

KEY MESSAGES

Sub-epithelial hyalinization is a significant feature for predicting recurrence in OKC.

Cross-sectional observational study evaluating the association between odontogenic cystic content and size

OBJECTIVES

To evaluate and correlate the cystic content and the size of odontogenic cysts.

METHODS

The study included 29 cases of odontogenic cysts reported in the Outpatient Department of Sharad Pawar Dental College. The cystic aspirate was analyzed for levels of sodium, potassium, calcium, chloride, total protein, globulin, albumin, and cholesterol. The sodium/potassium ratio was calculated. Pearson's correlation coefficient (ρ) was used to correlate the size of the cyst with the sodium/potassium ratio and other cystic contents. P < 0.05 was considered statistically significant.

RESULTS

A positive and statistically significant correlation (ρ = 0.625, p = 0.020) was noted between the sodium to potassium ratio and the size of the cyst. The correlation between the other cystic contents and the size of the cyst was not statistically significant (p > 0.05).

CONCLUSION

The sodium to potassium ratio is positively correlated with the radiographic size of cysts. A thorough analysis of cystic fluid components could provide valuable insights into the potential expansion of odontogenic cysts.

Analysis of expression of p53, p63 and proliferating cell nuclear antigen proteins in odontogenic keratocyst: An immunohistochemical study

Background:

Odontogenic keratocyst (OKC) is a benign intraosseous lesions (within the jaw bone) of odontogenic origin that account for about 10% of jaw cysts. They are characterized by an aggressive behavior with a relatively high recurrence rate. Early diagnosis and follow-up of the patient with OKC is important because the possibility of such patient there is develop to other features of Nevoid basal cell carcinoma syndrome in future. Considering the roles and effects of p53, p63 and proliferating cell nuclear antigen (PCNA) in cells proliferation, this study was designed.

Objectives:

To understand the behavior of epithelial cells in pathogenesis and biological aspects of OKC in diagnosis.

Materials and Methods:

Immunohistochemical (IHC)technique was performed in 21 cases of OKCs.

Results:

Immunological stained p53 cells were mainly located in the suprabasal layers. p63 and PCNA-positive cells were found throughout the lining epithelium including basal and suprabasal cell layers. The intensity of staining was more in p63 and PCNA than the p53 expression of the cystic epithelial lining.

Conclusions:

It is possible that the biological behavior of OKCs may be related to the suprabasal proliferative compartment in the cystic epithelium as observed. These proteins may participate in the regulation of epithelial cell differentiation. Taken together, these data may favor tumerigenesis on OKCs.

A Brazilian multicentre study of 2,497 isolated cases of odontogenic keratocysts

We present the frequency of cases of isolated odontogenic keratocysts submitted to microscopic examination at 10 Brazilian referral centres in Oral and Maxillofacial Pathology. In a retrospective (1953-2017) analysis, data on clinicoradiographic features and treatment of these lesions were collected and analysed descriptively. Among the 258,867 cases retrieved, 2,497 (0.96%) were isolated odontogenic keratocysts. In summary, an overview of individuals affected with isolated odontogenic keratocysts is reported herein. This lesion showed predilection for the posterior mandible of young adult men.

Stromal Expression of CD10 by Immunohistochemistry in Odontogenic Keratocyst (OKC), Dentigerous and Radicular Cysts and Its Correlation with Local Recurrence and Aggressive Behaviour

Objective:

To assess and compare the stromal expression of CD10 in OKC, dentigerous and radicular cysts.

Materials and Methods:

This comparative, cross sectional study was conducted at Armed Forces Institute of Pathology (AFIP), Rawalpindi, from Jan 2017 to Dec 2017. Total sixty cases comprising 20 of each OKC, Dentigerous and Radicular cysts were included in this study. Hematoxylin and eosin (H and E) sections were performed followed by immunohistochemical staining for CD10 antibody. Expression of CD10 was evaluated and compared. Results were analyzed by using SPSS version 20.0. Chi Square test was performed with P value < 0.05 was considered as significant.

Results:

A total of 60 cases, 20 of each OKC, dentigerous and radicular cysts were taken. In our study, 38 (63.3%) male and 22 (36.7%) female patients with the mean age of 32 ± 15 (mean ± SD) were included. Percentage of CD10 positive cells were highest in sub-epithelial stroma of OKC (95% cases) as compared to radicular and dentigerous cysts (60 and 70%) with highest number of cases showing intense staining in OKC 13(65%) as compared to other odontogenic cysts i-e 4(20%) and 2 (10%) respectively. There was a statistically significant association between odontogenic cysts and proportional score, intensity score and combined score of stromal CD10 expression (P=0.009, p=0.001 and p=0.000).

Conclusion:

In this study, we found that highest stromal CD10 expression in OKC as compared to dentigerous and radicular cyst, which might be due to aggressive behaviour and increased risk of recurrence in OKC. Expression of CD10 marker will further aid the clinician to plan appropriate surgical intervention and keep regular follow-ups to identify recurrences.

Odontogenic keratocyst with granular cell changes: A distinctive finding

Odontogenic keratocyst (OKC) originates from the dental lamina and is more commonly seen in the posterior mandible than in the maxilla. OKC is the most aggressive cyst of the oral cavity and is known for its rapid growth and its tendency to invade bone of the adjacent tissues. The recurrence rate of OKC is very high due to various reasons debated upon. Cases of OKC have shown the presence of calcifications, dentinoid formation and ossification. Here, we report the first case of OKC in a 27-year-old male showing granular cell changes.

Clinical and histomorphometric evaluation of decompression followed by enucleation in the treatment of odontogenic keratocyst

Background/purpose

The classification and treatment of odontogenic keratocyst (OKC) are controversial. The objective of this study was to present the efficiency of decompression followed by enucleation by clinical and histomorphometric evaluation for the treatment of OKC.

Materials and methods

Thirty four OKCs of 27 patients who underwent decompression followed by enucleation were included in this study. Clinical and histomorphometric analysis were performed.

Results

The average decreasing rate was 59% in maximum diameter, 66% in the amount of the volume for the average of period of the decompression was 9.8 months. The mean of increasing rate of the thickness of the epithelial lining was 921.16%. There were no recurrences for a mean follow-up period of 5.8 years. The thin and friable cyst wall of the OKC was changed to thickened, hard type.

Conclusion

The decompression was found to be effective and reliable as a treatment of the OKC to decrease the recurrence tendency, even for Gorlin-Goltz syndrome.

[Spontaneous bone regeneration following ceratocystic odontogenic tumor]

A patient presents with a keratocystic odontogenic tumour of the left maxillary sinus. In computed tomography scans, extensive pressure-induced osseous atrophy of the sinus walls is detected. Endoscopic cystectomy of the tumour was performed, with subsequent clinical follow-up. A second computed tomography scan revealed almost complete regeneration of the sinus walls. Where spontaneous regeneration of osseous structures is possible, restraint should be exercised when assessing indications for bony reconstruction during initial conservative surgery such as enucleation.

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.

Immunohistochemical expression of glucose transporter 1 in keratin-producing odontogenic cysts

Background

Keratin-producing odontogenic cysts (KPOCs) are a group of cystic lesions that are often aggressive, with high rates of recurrence and multifocality. KPOCs included orthokeratinised odontogenic cyst (OOC) and parakeratotic odontogenic cysts, which are now considered true tumours denominated keratocystic odontogenic tumours (KCOTs). GLUT1 is a protein transporter that is involved in the active uptake of glucose across cell membranes and that is overexpressed in tumours in close correlation with the proliferation rate and positron emission tomography (PET) imaging results.

Methods

A series of 58 keratin-producing odontogenic cysts was evaluated histologically and immunohistochemically in terms of GLUT1 expression. Different data were correlated using the beta regression model in relation to histological type and immunohistochemical expression of GLUT1, which was quantified using two different morphological methods.

Results

KPOC cases comprised 12 OOCs and 46 KCOTs, the latter corresponding to 6 syndromic and 40 sporadic KCOTs. GLUT1 expression was very low in OOC cases compared with KCOT cases, with statistical significant differences when quantification was considered. Different GLUT1 localisation patterns were revealed by immunostaining, with the parabasal cells showing higher reactivity in KCOTs. However, among KCOTs cases, GLUT1 expression was unable to establish differences between syndromic and sporadic cases.

Conclusions

GLUT1 expression differentiated between OOC and KCOT cases, with significantly higher expression in KCOTs, but did not differentiate between syndromic and sporadic KCOT cases. However, given the structural characteristics of KCOTs, we hypothesised that PET imaging methodology is probably not a useful diagnostic tool for KCOTs. Further studies of GLUT1 expression and PET examination in KCOT series are needed to confirm this last hypothesis.

Participation of hMLH1, p63, and MDM2 proteins in the pathogenesis of syndromic and nonsyndromic keratocystic odontogenic tumors

OBJECTIVES

To evaluate the expression of hMLH1, p63, and MDM2 in Gorlin syndrome-associated keratocystic odontogenic tumors (SKOTs) and nonsyndromic keratocystic odontogenic tumors (NSKOTs).

STUDY DESIGN

Seventeen primary NSKOTs, 17 SKOTs, and 8 recurrent NSKOTs were analyzed by using immunohistochemistry.

RESULTS

No significant differences in the hMLH1, p63, or MDM2 labeling indices were observed between groups (P = .398; P = .232; P = .426, respectively). Higher hMLH1 immunoexpression was found in the basal layer of primary NSKOTs. Most KOTs exhibited p63 immunoexpression in the upper layers of the epithelium. MDM2 immunoexpression was observed in the upper epithelial layers of SKOTs and recurrent NSKOTs.

CONCLUSION

It was not possible to correlate the immunoexpression of hMLH1, p63, and MDM2 in SKOTs and primary and recurrent NSKOTs, suggesting that these proteins exert independent effects on the development of these groups of tumors.

NCAM (CD56) expression in keratin-producing odontogenic cysts: aberrant expression in KCOT

Objective

To investigate immunohistochemically the expression of neural cell adhesion molecule (NCAM), which has been identified as a signaling receptor with frequent reactivity in ameloblastomas (AB), in a series of keratin-producing odontogenic cysts (KPOCs).

Material and methods

Immunohistochemical expression of NCAM, using a monoclonal antibody, was determined in a series of 58 KPOCs comprising 12 orthokeratinized odontogenic cysts (OOCs) and 46 keratocystic odontogenic tumors (KCOTs), corresponding to 40 non-syndromic KCOT (NS-KCOTs) and 6 syndromic KCOT (S-KCOTs), associated with nevic basocellular syndrome (NBCS).

Results

NCAM expression was negative in all OOCs, but 36.45% of KCOTs exhibited focal and heterogeneous expression at the basal cell level, as well as in basal budding areas and the basal cells of daughter cysts. The latter two locations were especially applicable to S-KCOTs, with focal NCAM reactivity occurring in 66.66% of cases.

Conclusions

Aberrant NCAM expression, in KCOTs but especially in S-KCOTs, together with its immunomorphological location, suggests that this adhesion molecule and signaling receptor plays a role in the pathogenesis of KCOTs, with a probable impact on lesional recurrence.

Electronic supplementary material

The online version of this article (doi:10.1186/s13005-015-0060-2) contains supplementary material, which is available to authorized users.

Smoothened gene alterations in keratocystic odontogenic tumors

Background

It has been widely demonstrated that the hedgehog pathway is strongly associated with basal cell carcinoma of the skin (NBCCS). To assess potential DNA alterations related to keratocystic odontogenic tumors (KCOTs), we sequenced smoothened (SMO) genes in 12 sporadic KCOTs.

Methods

Polymerase chain reaction (PCR), capillary electrophoresis and dideoxy chain-termination sequencing were used to examine potential DNA alterations in sporadic KCOTs.

Results

Five alterations in SMO genes were detected. Four of these mutations consisted of two synonymous and three missense mutations; two of which have not been reported to date (c.T776A, c.T1281G).

Conclusions

SMO genes may play an important role in the sonic hedgehog (SHH) pathway and could also be responsible for generating KCOTs and NBCCS. However, their influence on SHH signaling remains to be elucidated.

Bimaxillary keratocystic odontogenic tumour: a case of diagnostic and therapeutic difficulty

Keratocystic odontogenic tumour (KCOT) is a benign cystic intraosseous tumour of odontogenic origin that is usually solitary except when syndromic. It rarely occurs in the maxilla; therefore a rapidly progressive, nonsyndromic bimaxillary KCOT with locoregional extension poses significant diagnostic and management challenges. To the best of the authors' knowledge, documentation of a nonsyndromic bimaxillary KCOT is nonexistent in the English literature. We therefore present the case of an extensive bimaxillary KCOT in a 38-year-old Nigerian male.