A review of odontogenic keratocysts and the behavior of recurrences

Use of Virtual Surgical Planning as an Adjunct for Enucleation of Multiple Recurrent Odontogenic Keratocysts: Case Report

This case report describes an interesting use of virtual surgical planning to fabricate tooth-borne cutting guides to assist in localization and enucleation of multiple recurrent odontogenic keratocysts close to the inferior alveolar nerve. The 3-dimensional models generated and cutting guides increased the accuracy and precision of the procedure and decreased surgical time and potential patient morbidity.

Retrospective clinical study of multiple keratocystic odontogenic tumors in non-syndromic patients

Objectives

A keratocystic odontogenic tumor (KOT) is a type of odontogenic tumor that mainly occurs in the posterior mandible. Most KOTs appear as solitary lesions; however, they sometimes occur as multiple cysts. This study analyzed the clinical features of multiple KOTs.

Materials and Methods

The participants were diagnosed with KOT by biopsy with multiple surgical sites, and were patients at the Pusan National University Hospital and the Pusan National University Dental Hospital from January 1, 2005 to March 31, 2016. Charts, records, images and other findings were reviewed.

Results

A total of 31 operations were conducted in 17 patients. The mean patient age was 28.4±20.1 years. Multiple KOTs were found to occur at a young age (P<0.01). The predominant sites were in the posterior mandible (28.6%). Most cases of multiple lesions appeared in both the upper and lower jaw, and 40.3% of lesions were associated with unerupted and impacted teeth. The overall recurrence rate measured by operation site was 10.4% (8/77 sites). No patients were associated with nevoid basal cell carcinoma syndrome.

Conclusion

The pure recurrence rate was lower than estimated, but there was a higher possibility of secondary lesions regardless of the previous operation site; therefore, long-term follow-up is necessary.

Odontogenic Keratocysts as First Manifestation of Nevoid Basal Cell Carcinoma Syndrome: Surgical Management and Immunohistochemical Analysis

Nevoid Basal Cell Carcinoma Syndrome (NBCCS), also known as Gorlin syndrome, is a rare autosomal dominant disorder, with no gender predilection. Individuals with NBCCS are commonly diagnosed between 17 and 35 years old and can present multiple basal cell carcinomas scattered throughout the body, presence of recurrent and early-onset odontogenic keratocysts (OKCs) and skeletal abnormalities. This article describes a case of a 13-year-old white boy who referred complaining of facial asymmetry. Extraoral examination revealed volumetric increase displacing the nasal ala from the right side and extended to the zygomatic bone. The intraoral evaluation showed mixed dentition with moderate degree of malocclusion. In addition, bilateral vestibular fornix swelling was observed in the upper canine region. An increase in volume was also detected on the hard palate on the right side. Computed tomography revealed multiple hypodense lesions with cystic appearance. The aspiration was positive, with a yellowish aspirate of serous consistency of all lesions. Given the numerous lesions, it was decided to decompress them for posterior enucleation procedures. In addition to other manifestations, the patient was diagnosed with NBCCS. Although common, the occurrence of OKCs in pediatric patients, especially in multiple lesions, is highly indicative of NBCCS, and its investigation should be considered, even in the absence of other signs of this syndrome. Synchronous decompression was satisfactory and can be used in similar cases of multiple cystic lesions.

Squamous cell carcinoma arising within a maxillary odontogenic keratocyst: A rare occurrence

Squamous cell carcinoma (SCC) arising within the lining of an odontogenic keratocyst (OKC) is a rare occurrence. Although potentially locally destructive, OKC is a benign odontogenic process that typically presents with clinical and radiographic features characteristic of a benign intraosseous neoplasm. We present the clinical and radiographic features of a maxillary mass that demonstrated SCC arising from the lining of an OKC. Although the initial clinical and radiographic presentation suggested an infection or malignant neoplasm, biopsies revealed an infiltrative well-differentiated SCC contiguous with and arising from the focus of a pre-existing OKC. The patient subsequently underwent a type II hemi-maxillectomy with neoadjuvant chemoradiation. This report discusses the clinical and radiographic features associated with intraosseous malignancies, especially those arising from an otherwise benign odontogenic lesion. While the majority of OKCs are benign, the current report illustrates the potential for carcinomatous transformation within the lining of an OKC.

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.

Keratocystic odontogenic tumor

OBJECTIVE

to evaluate the frequency of keratocystic odontogenic tumor (KOT) in the Oral Surgery Service (OSS) of the University Hospital Clementino Fraga Filho of the Federal University of Rio de Janeiro (HUCFF / UFRJ), with respect to recurrence rate, gender, age of recurrence and location of the injury Methods: clinical records were reviewed and histopathological reports of KOT patients of the HUCFF/UFRJ between 2002 and 2012. Patients diagnosed with KOT were divided into two groups for the occurrence of relapse: positive (n=6) and negative (n=19) Results: regarding the location, there was a predilection for the mandible. In the average age of patients in the positive group was 40.5 and the negative group, 35.53. In the distribution by gender, positive group showed equal distribution, different from that observed in the negative group, which showed a predilection for males Conclusion: KOT was the second most frequent injury in our patients, recurrence was lower among males and had the jaw as most affected location.

Use of refrigerant spray of a propane/butane/isobutane gas mixture in the management of keratocystic odontogenic tumors: a preliminary study

PURPOSE

Keratocystic odontogenic tumor (KCOT) is an aggressive benign tumor and the management by complete enucleation followed by cryotherapy maintains the inorganic bone matrix, resulting in better repair and reduces the rates of recurrence. A refrigerant spray with a propane/butane/isobutane gas mixture has been pointed to as an alternative to liquid nitrogen, because the device is easy to handle and contain within the cavity, providing better control and lower risk of injury to the adjacent soft tissue. Thus, the aim of this study was to evaluate the outcome of enucleation followed by cryosurgery using a refrigerant spray of this gas mixture in ten patients diagnosed with KCOT.

METHOD

The biggest lesions received a prior treatment consisting of marsupialization to decrease the tumor size. During the surgeries, the lesions were removed by enucleation and the surgical site was sprayed with the gas mixture.

RESULTS

Wound dehiscence was observed in all cases, which healed by the second intention. The mean follow-up period was 64.3 months (range 24-120 months). Eight of the ten patients showed no evidence of clinical or radiographic recurrence. Pathologic fractures and infections were not observed.

CONCLUSIONS

The results obtained suggest that enucleation followed by cryosurgery is an effective therapy for managing KCOT.

Odontogenic Cysts and Neoplasms

This article reviews a myriad of common and uncommon odontogenic cysts and tumors. The clinical presentation, gross and microscopic features, differential diagnosis, prognosis, and diagnostic pitfalls are addressed for inflammatory cysts (periapical cyst, mandibular infected buccal cyst/paradental cyst), developmental cysts (dentigerous, lateral periodontal, glandular odontogenic, orthokeratinized odontogenic cyst), benign tumors (keratocystic odontogenic tumor, ameloblastoma, adenomatoid odontogenic tumor, calcifying epithelial odontogenic tumor, ameloblastic fibroma and fibroodontoma, odontoma, squamous odontogenic tumor, calcifying cystic odontogenic tumor, primordial odontogenic tumor, central odontogenic fibroma, and odontogenic myxomas), and malignant tumors (clear cell odontogenic carcinoma, ameloblastic carcinoma, ameloblastic fibrosarcoma).

Role of HIF-1α and CASPASE-3 in cystogenesis of odontogenic cysts and tumors

OBJECTIVES

Odontogenic cysts and tumors are the most relevant lesions that affect the gnathic bones. These lesions have in common the formation of cystic areas and this common feature may suggest involvement of similar mechanisms. The hypoxia inducible factor 1 alpha (HIF-1α), a responsive protein to hypoxia and caspase-3, an irreversible apoptosis marker, may contribute to cyst formation. Thus, this study aimed to investigate the immunoexpression of these proteins in odontogenic cysts and tumors.

MATERIAL AND METHODS

Twenty cases of ameloblastoma, keratocystic odontogenic tumor (KOT) (n = 20), radicular cyst (RC) (n = 18), dentigerous cyst (DC) (n = 11), calcifying cystic odontogenic tumor (n = 8), and dental follicle (DF) (n = 10) were used to investigate HIF-1α and caspase-3 expression in sequential serial cuts by immunohistochemistry.

RESULTS

HIF-1α was overexpressed in RC, DC, and ameloblastoma when compared with DF. The basal and sometimes the lower suprabasal layer showed no or very low expression in DC, KOT, and ameloblastoma, the last also showing strong expression in solid epithelial areas and initial cystic formation regions. Caspase-3 was found to be overexpressed in all lesions, with the highest expression in odontogenic cysts compared to tumors. HIF-1α and caspase-3 were localized in similar areas of the same lesions, especially in the epithelium surrounding cystic formations.

CONCLUSIONS

This study showed distinct immunoexpression of HIF-1α and caspase-3 in odontogenic cyst and tumors, with higher expression observed in odontogenic cysts.

CLINICAL RELEVANCE

These findings suggest a possible correlation between hypoxia, apoptosis, and cystogenesis, leading to understand the mechanisms responsible to cystic formation in odontogenic lesions.

Surgical removal of keratocystic odontogenic tumours via a Le Fort I osteotomy approach: a retrospective study of the recurrence rate

The keratocystic odontogenic tumour (KCOT) is one of the most aggressive odontogenic cysts and has a high recurrence rate. The treatment of these tumours is the subject of debate. A KCOT in the posterior maxilla with sinus involvement is rare. Few reports have been published in the literature. The purpose of this study was to evaluate the recurrence rate after surgical removal of maxillary KCOTs via a Le Fort I osteotomy. A search was performed to identify patients with a follow-up time of at least 5 years. Nine patients were included in the study. The following clinical variables were analyzed: age at surgery, sex, symptoms, site and size of the tumour, surgical approach, and recurrence rate. The surgical approaches were curettage (n=6) and enucleation (n=3). Recurrence was seen in three patients (33%); all had multilocular tumours. No recurrence was seen in patients with unilocular tumours. The Le Fort I osteotomy approach allows direct visualization and ensures wide excision, minimizing the risk of recurrence. In this series, cases with a multilocular KCOT showed a higher risk of recurrence due to the difficulty of removing the tumour in total. All recurrences took place within 2 years of the intervention; a 5-year follow-up is recommended.

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.

KCOT Occurring in Bilateral Maxillary Sinus in Non-Syndromic Patient

Odontogenic Keratocyst (OKC) also termed as Keratocystic Odontogenic Tumour (KCOT) (WHO 2005) is a pathology with unique behavior because of which it is under much scrutiny and continued study. The pathology usually presents itself commonly in mandible and less commonly in maxilla. The occurrence of KCOT in maxillary sinus is reported as rare and multiple occurrences are mostly associated along with the presence of Nevoid Basal Cell Carcinoma (NBCC) syndrome. Here, we present a rare case of bilateral Maxillary OKC involving maxillary sinuses, without the presence of NBCC syndrome. An interesting feature of this case is the presence of left upper third molar in ectopic position in maxillary sinus and a vertically impacted right third molar suggesting an origin from the dental lamina.

Odontogenic Keratocyst in Children: A Review

OBJECTIVE

Is to highlight the characteristics and management of odontogenic keratocyst in children only.

MATERIAL AND METHOD

Computerized search in pubmed between (2005-2015) using specific words such as odontogenic keratocyst in children, odontogenic keratocyst association with Gorlin-Goltz syndrome with abstract written in English only.

RESULT

During computerized literature search 77 articles in the years (2005-2015) were found. All these publications were miscellaneous studies including case series and case reports. Only 35 papers were selected which conform to our criteria. Most of the papers indicate that the histological type of keratocyst prevalent in children was parakeratinized variant, and most of the cases occurred in maxilla rather than mandible.

CONCLUSION

We recommend that the surgeons who treat keratocysts in children take into consideration the late presentation in addition to the destructive nature and high recurrence rate. General practitioners face difficulty in early detection and referral of children with keratocysts or Gorlin syndrome. Treatment by multidiscplinary team is important if associated with Gorlin's syndrome Postoperative follow up is advised every 6 months.

Magnetic resonance imaging of the maxilla and mandible: signal characteristics and features in the differential diagnosis of common lesions

The maxilla and mandible are among the most difficult areas of the body to image with magnetic resonance techniques owing to the geometry of the jaws as well as the frequent susceptibility artifacts from dental restorations or appliances. This chapter briefly reviews the essentials of imaging techniques and basic anatomy and discusses the most common inflammatory conditions, benign and malignant lesions of the jaws, and temporomandibular joint. This review emphasizes and illustrates specific magnetic resonance features that facilitate characterization and diagnostic differentiation of these lesions. As the focus of this review is on the differentiation of infection and benign and malignant disease, a discussion of internal derangements and associated inflammatory disorders of the temporomandibular joint is beyond the scope of this review and is not discussed.

Keratocystic Odontogenic Tumours: Etiology, Pathogenesis and Treatment Revisited

INTRODUCTION

Among the pathological entities that affect the maxillofacial region, Keratocystic odontogenic tumour has been subject to a lot of debates, controversies and speculations because of its diverse nature and high recurrence rates.

MATERIALS AND METHODS

The authors conducted a search in English literature using the following keywords; "Odontogenic keratocyst" and "Keratocystic odontogenic tumour". The aim of the paper was to review all aspects of the entity, including etiology, pathogenesis, clinical and radiological manifestations, growth potential, recurrence and treatment modalities.

CONCLUSION

The controversial nature of the pathology not withstanding, there is in general a broad consensus on treating the entity conservatively with emphasis on a long term review.

Lesions of the Jaw

Imaging of lesions within the maxilla and mandible is often fraught with difficulty owing to the similarity in the imaging appearance of a diverse array of pathological processes. Principally, lesions arise from either odontogenic sources or from primary bone lesions. The response of the cancellous and cortical bone to pathologic insult can be expressed either through an osteolytic or an osteoblastic response; thus the majority of lesions within the jaws can be classified as cystic or lytic appearing, sclerotic, or a mixture of the two. This article will review the imaging features of the most common cysts, fibro-osseous lesions, benign and malignant neoplasms, and highlight those features key to the differential diagnosis.

Diagnostic Factors of Odontogenic Cysts in Iranian Population: A Retrospective Study Over the Past Two Decades

BACKGROUND

Early diagnosis of odontogenic cysts due to their silent progression is always a challenging problem for clinicians.

OBJECTIVES

The current study aimed to evaluate the frequency of odontogenic cysts and related factors in a selected Iranian population.

PATIENTS AND METHODS

The current cross-sectional study was conducted on 312 patients' recorded data in Taleghani Hospital, Tehran, Iran, from April 1993 to December 2013. All related data were extracted from the records and categorized in tables. The correlation between the variables was analyzed by either chi-square or multinominal logistic regression tests. The P values < 0.05 were considered significant.

RESULTS

Evaluation of 312 patients' records (185 males and 127 females) with the mean age of 27.6 showed that Odontogenic Keratocyst (OKC) was the most common odontogenic cyst of all followed by the dentigerous cyst as the second most common lesion. Most of the patients were in the second or third decades of their lives, although there was no statistically significant age distribution. The finding of the current study showed that calcifying odontogenic cyst (COC) occurrence was significantly related to the history of trauma. Enucleation and curettage of the odontogenic cysts were the most common treatment plans of all.

CONCLUSIONS

The current study showed that clinicians should consider the many factors associated with the occurrence of odontogenic cysts.

Keratocystic odontogenic tumor invading the maxillary sinus: a case report of collaborative surgery between an oral surgeon and an otorhinolaryngologist

We report a case of keratocystic odontogenic tumor (KCOT) in a 21-year-old female patient. The patient was referred to our clinic from a dental clinic for the radical treatment of recurrent KCOT in the maxilla. She had undergone conservative drainage surgery twice at that clinic.The tumor was cystic and covered with a bony capsule, which extended high into the maxillary sinus. A pinhole fistula, which was created during a previous surgery, was identified in the gingivobuccal sulcus. The whole tumor was successfully removed using a bidirectional approach from the fistula and from the antrostomy in the middle meatus. This report shows that the intimate collaboration between an otorhinolaryngologist and an oral surgeon could provide a minimally invasive, and at the same time, radical surgical treatment for certain kinds of tumor in the head and neck region. We also recommend the introduction of endoscopic surgeries by the oral surgeon.

Jaw cysts diagnosed in an Italian population over a 20-year period

BACKGROUND

Cysts of the jaws (JCs) are an important topic of oral pathology, but few epidemiological data are present in the literature, in particular about the potential of recurrence. The aim of this study was to describe a case series of JCs from a single institution, evaluating the frequency, the site, the age distribution, and the percentage of recurrence of all types of JCs.

METHODS

All JCs present in the histological records of the Section of Anatomic Pathology of the University of Bologna at Bellaria Hospital from 1992 to 2012 were retrieved.

RESULTS

A total of 1136 jaws cysts were obtained, of which 1117 (98.3%) were odontogenic and 19 (1.7%) were nonodontogenic. About odontogenic cysts (OCs), the most frequent was the radicular cyst (538 cases), followed by parakeratinized keratocystic odontogenic tumor (pKOT, 193 cases) and dentigerous cyst (120 cases). Among pKOT, 21 out of 193 cases (10.89%) showed a recurrence after a mean time of 4.5 years (range, 1-12 years). During follow-up (mean 11 years, range 1-19 years), all 3 cases of botrioid cysts, 12 out of 46 cases of unicystic ameloblastoma (26.09%), 2 out of 20 cases of calcifying OCs (10%) and 2 out of 538 cases of radicular cyst (0.37%) showed a recurrence.

CONCLUSION

Our study confirms that the distribution pattern of JCs in Italy is relatively similar to other studies worldwide and emphasizes the importance of recognizing the different histological types of JCs for their potential local aggressive behavior.

Clinical, radiological and therapeutic features of keratocystic odontogenic tumours: a study over a decade

Factors associated with the potential for recurrence of keratocystic odontogenic tumours (KCOT) still remain to be clearly determined and no consensus exists concerning the management of KCOT. The purpose of this study was to evaluate different clinical factors associated with KCOT and its treatment methods. A retrospective review was performed of 55 cases treated from 2001 to 2010. Of the 55 cases, 27% were associated with an impacted or semi-impacted tooth. The majority of the lesions (82%) were located in tooth-bearing areas, and the overall mandibular to maxilla ratio of tumour occurrence was 5:1. The treatment options included enucleation, marsupialisation, or peripheral ostectomy, with or without the use of Carnoy´s solution. Recurrence was found in 14 cases (25%). No significant association was seen between recurrence and age, symptomatic cases, location of the lesion, or unilocular or multilocular appearance. The recurrence rate was higher in the group with tooth involvement, more marked in cases with third molar involvement. Statistical analysis showed a significant relation between recurrence and the type of treatment, with higher rates in cases treated with enucleation associated with tooth extraction. In our series, those cases with a closer relation with dental tissues showed a higher risk of recurrence, suggesting the need for a distinct classification for peripheral variants of KCOT.

Key words:Keratocystic odontogenic tumour, Odontogenic keratocyst, Odontogenic cysts, Keratocyst, Carnoy’s solution.

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.

Marsupialization is the optimal treatment approach for keratocystic odontogenic tumour

Previous published studies fail to present any consensus on a uniform treatment protocol for keratocystic odontogenic tumour (KCOT). Optimal management for KCOT was investigated by comparing the treatment outcome of marsupialization to the enucleation and radical resection. An online electronic databases search was carried out through the PubMed, Embase and Web of Science. The statistical analysis was performed by RevMan version 5.2. Fourteen eligible studies were identified for analysis. Fourteen studies evaluated included 938 patients, of which 853 underwent enucleation alone or plus adjunctive therapy, 110 underwent marsupialization with or without secondary adjunctive therapy, and 86 underwent radical resection alone. The marsupialization was significantly associated with lower recurrence compared to enucleation and resection in KCOT treatment (RR = 0.56, 95% CI 0.4-0.78, P = 0.0006 and RR = 0.32, 95% CI 0.15-0.69, P = 0.004, respectively). The results suggest that the marsupialization reduce the recurrence of KCOT better than enucleation and surgical resection and it may be the optimal approach for KCOT treatment.

Keratocystic Odontogenic Tumor Surgical Management: Retrospective Analysis on 77 Patients

In 2005 the WHO introduced the former odontogenic keratocyst to the category of benign odontogenic tumours. The change in terminology was based on the observation that the odontogenic keratocyst behaves as a neoplasm and not like a benign cystic lesion. The present paper is a retrospective analysis on the management of keratocystic odontogenic tumor over a period of 11 years (2001–2012) in the Department of Maxillo-Facial Surgery at the University of Rome “Sapienza”, with particular focus on the surgical choices and the relative rates of relapse. The patient population consisted of 34 females and 43 males. Administered treatment modalities consisted of enucleation in 55 cases and radical resection in 22 cases. Nineteen percent of patients who underwent enucleation suffered KCOT relapse. No relapse was observed in the radical resection group with follow-up of 3–7 years. The goals of the treatment include elimination of the pathology and decrease of potential recurrence while minimizing harm to the patient. In the Authors' experience, conservative treatment still encompasses a high rate of recurrence; otherwise, resection provides the lowest recurrence rate, yet causes the most suffering to the patient. The issue surgeons encounter is whether to choose a conservative approach, reducing the morbidity to the patient, knowing that several operations may be required to eliminate recurrence; or being more aggressive and potentially more destructive, at the same time ensuring the best condition to avoid recurrence. Other studies are needed in order to find definitive guidelines for this challenging pathology.

Keratocystic odontogenic tumour arising as a periapical lesion

AIM

To document a case of a keratocystic odontogenic tumour (KOT) involving the apical region in the maxilla mimicking a periapical lesion of endodontic origin.

SUMMARY

Benign and malignant tumours, including odontogenic lesions, can be erroneously diagnosed as periapical radiolucencies. KOTs mimicking periapical lesions of endodontic origin are uncommon, especially when the lesions involve the maxilla. This article describes a 55-year-old man with a well-delimited, oval-shaped, radiolucent lesion, occupying the middle and apical third of teeth 22 and 23. After 30 days, the clinical and radiographic findings remained unchanged and the patient was referred for surgical removal of the lesion. Clinical, radiographic and histopathological features are also discussed and compared with current literature.

Study of the biologic behavior of odontogenic keratocyst and orthokeratinaized odontogenic cyst using TGF-alpha and P53 markers

Odontogenic keratocyst (OKC) is an aggressive cyst, and its recurrence rate is higher than that of other odontogenic cysts. Orthokeratinized odontogenic cyst (OOC) is less aggressive than OKC, but bears the probability of carcinomatous changes. In this study, we evaluated the expression and intensity of P53 and TGF-alpha in order to compare the biologic behavior or probable carcinomatous changes of these two cysts. In this cross-sectional study, 15 OKC and 15 OOC were stained immunohistochemically for P53 and TGF-alpha using the Novolink polymer method. Then, all slides were examined by an optical microscope with 400× magnification, and the stained cells in the basal and parabasal layers were counted. Finally, the results were analyzed by the Mann-Whitney and Wilcoxon tests (P-value<0.05). The difference between the expression of P53 and TGF alpha in the basal layer of OKC and OOC was not statistically significant (P-value>0.05), but the expression of P53 and TGF-alpha in the parabasal layer in OKC was statistically higher compared to OOC (P<0.05). Considering the known role of P53 and TGF-alpha in malignant changes and the higher expression of P53 and TGF-alpha in OKC compared to those in OOC, the probability of carcinomatous changes was higher in OKC than in OOC.

Keratocystic odontogenic tumor: systematic review with analysis of 72 additional cases from Mumbai, India

OBJECTIVE

The aim of this systematic review was to assess the clinical and imaging findings of keratocystic odontogenic tumor (KOT). This article also attempts to determine the prevalence of KOTs and orthokeratinized odontogenic cyst (OOC) in the western Indian population and to compare demographic and radiographic findings of KOT of our cohort with that of the rest of the world.

STUDY DESIGN

Relevant publications on KOT were reviewed from the published literature from 1976 to March 2012. Data regarding the 72 additional cases from Mumbai also were analyzed.

RESULTS

Sixty-five reports were identified for this systematic review. The findings were divided into 4 global groups for analysis. The prevalence of KOT was 0.0173% and that of OOC 0.0012%. Male sex, mandible, and the unilocular variation were predominant for the additional cases.

CONCLUSIONS

The characterization of the KOT lesions was accomplished, taking into consideration the variations to the western Indian population.

Recurrent keratocystic odontogenic tumor in the masseter muscle overlying the boney perforations: a case report

Keratocystic odontogenic tumor (KCOT) is a benign intraosseous neoplasm of odontogenic origin with high recurrence rates and tendency to invade adjacent tissue. Most recurrences occur in the first 5 years after surgery and are usually located at the site of the primary tumor in the jaws. We report a rare case of KCOT which recurred in the masseter muscle 14 years after segmental mandibulectomy and autogenous frozen lesional mandible reimplantation. The patient had undergone enucleation of KCOT in the right mandible 20 years before segmental mandibulectomy. This case could further demonstrate the aggressive behavior of KCOT.

Prevalence and distribution of odontogenic cyst in Indian population: a 10 year retrospective study

The purpose of this study is to determine the prevalence of odontogenic cyst in an Indian population and compare it with various reports from the other geographic areas of the world. The files on odontogenic jaw cysts treated between 2001 and 2011 at the oral and maxillofacial surgery unit were retrieved retrospectively. Patient's demographic information mainly age, sex and location of the lesion was recorded and analyzed using descriptive statistics. The diagnosis of odontogenic cyst accounted in 150 cases and accounted for 15.31 % of all lesions biopsied throughout the period. Mean age of the patient was 32.2 years, and 58 % were males. The overall male to female ratio was 1.38:1. Radicular cyst was most prevalent histological type (48.67 %) followed by dentigerous cyst, odontogenic keratocyst, lateral periodontal cyst, paradental cyst, residual cyst, adult gingival cyst, glandular odontogenic cyst, calcifying odontogenic cyst. The most common locations of the odontogenic cysts were the mandibular (49.33 %) and posterior region (33.33 %). The distribution pattern of odontogenic cyst in this study is relatively similar to that in other parts of the world but there are some geographic differences with regard to the relative frequency, sex, and anatomic distribution of the odontogenic cyst.

Co-expression of Ki-67 and p53 protein in ameloblastoma and keratocystic odontogenic tumor

OBJECTIVES

The purpose of this study was to evaluate the cell proliferation and p53 protein expression in ameloblastomas (ABs), keratocystic odontogenic tumor (KCOT) and dentigerous cyst (DC).

METHOD

The immunohistochemistry were carried out for Ki-67 and p53 protein expression by using MIB-1 clone and DO-7 clone, respectively, in ABs (n = 23), KCOT (n = 32), DC (n = 30), normal oral mucosa (NOM) (n = 12) and fetal oral mucosa (FOM) (n = 10).

RESULTS

Both the Ki-67 LI Labeling index (LI) and p53 LI was significantly higher in ABs than KCOT, DC, NOM and FOM. The Ki-67 LI and p53 LI was significantly higher in KCOT as compared to DC. Ki-67 LI and p53 LI was observed in descending order in ABs, KOCT, FOM, NOM and DC. There was significant correlation between Ki-67 expression and p53 expression in ABs, KCOT, DC and NOM. The densely stained p53 positive cells were noted higher in ABs than KCOT. The very few densely p53 positive cells were noted in DC, NOM and FOM.

CONCLUSION

The results suggest that the p53 protein expression does not necessarily imply an association with malignant disease and/or p53 gene mutation, but a tendency to be expressed in an increasing quantitative and qualitative manner, as the biologic behavior of odontogenic cyst or tumors becomes more aggressive. p53 over-expression may promote cell proliferation in odontogenic lesions. Thus, it can be stipulated that Ki-67 and p53 protein expression can be used as a prognostic marker in odontogenic lesions.

Cell proliferation and apoptosis in ameloblastomas and keratocystic odontogenic tumors

A high proliferative activity of the odontogenic epithelium in ameloblastoma (AM) and keratocystic odontogenic tumor (KOT) has been demonstrated. However, no previous study has simultaneously evaluated cell proliferation and apoptotic indexes in AM and KOT, comparing both lesions. The aim of this study was to assess and compare cell proliferation and apoptotic rates between these two tumors. Specimens of 11 solid AM and 11 sporadic KOT were evaluated. The proliferation index (PI) was assessed by immunohistochemical detection of Ki-67 and the apoptotic index (AI) by methyl green-pyronine and in situ DNA nick end-labelling methods. KOT presented a higher PI than AM (p<0.05). No statistically significant difference was found in the AI between AM and KOT. PI and AI were higher in the peripheral cells of AM and respectively in the suprabasal and superficial layers of KOT. In conclusion, KOT showed a higher cell proliferation than AM and the AI was similar between these tumors. These findings reinforce the classification of KOT as an odontogenic tumor and should contribute to its aggressive clinical behavior.

Keratocystic odontogenic tumours of the jaws and associated pathologies: a 10-year clinicopathologic audit in a referral teaching hospital in Kenya

AIM

To establish the pattern of occurrence and the clinicopathological features of keratocystic odontogenic tumour (KCOT) over a 10-year period.

MATERIALS AND METHOD

Patients from the University of Nairobi Dental Hospital treated for KCOT were included in the study over a 10-year period. The study highlights the demographic, clinico-radiological and histological features of these tumours.

RESULTS

A total of 22 confirmed cases of KCOTs were recorded with equal gender prevalence; (M:F = 1.44:1). The age range of the patients was from 10 to 69 years with a peak in the second decade of life (mean = 27.5 yrs). Of the 22 cases, 15 (68.2%) occurred in the mandible of which eight (53.3%) involved the body, five (33.4%) the angle and ramus. Six (27.3%) occurred in the maxilla, and one (4.5%) was in both jaws and was associated with Gorlin-Goltz Syndrome. The most common presenting complaint in most patients was swelling 54.6%, and in 18.2% was incidental finding. Eight (36.4%) cases showed satellite cysts upon pathologic evaluation. Thirteen (59.1%) cases were managed by surgical excision, while nine (40.9%) were managed by enucleation.

CONCLUSION

Based on the outcome of this study, KCOT present mostly in body, angle and ramus of the mandible and its peak is in the second decade of life.

Surgical management of dentigerous cyst and keratocystic odontogenic tumor in children: a conservative approach and 7-year follow-up

Dentigerous cyst (DC) is one of the most common odontogenic cysts of the jaws and rarely recurs. On the other hand, keratocystic odontogenic tumor (KCOT), formerly known as odontogenic keratocyst (OKC), is considered a benign unicystic or multicystic intraosseous neoplasm and one of the most aggressive odontogenic lesions presenting relatively high recurrence rate and a tendency to invade adjacent tissue. Two cases of these odontogenic lesions occurring in children are presented. They were very similar in clinical and radiographic characteristics, and both were treated by marsupialization. The treatment was chosen in order to preserve the associated permanent teeth with complementary orthodontic treatment to direct eruption of the associated permanent teeth. At 7-years of follow-up, none of the cases showed recurrence.

Management and recurrence of keratocystic odontogenic tumor: a systematic review

OBJECTIVES

The objective of this study was to evaluate the most up-to-date treatment modalities and respective recurrence rates for keratocystic odontogenic tumor (KCOT).

STUDY DESIGN

A systematic review of the literature from 1999 to 2010 was undertaken examining treatment and recurrence rates for KCOT. Four inclusion criteria were defined for articles to then be analyzed against 8 standards.

RESULTS

Of the 2736 published articles, 8 met the inclusion criteria. When merging the data, enucleation and enucleation with adjunctive measures (other than Carnoy's solution) had recurrence rates of 25.6% and 30.3%, respectively. Marsupialization with adjunctive measures produced a recurrence rate of 15.8%, whereas enucleation with Carnoy's solution presented a recurrence rate of 7.9%. Only one resection case had recurrence (6.3%).

CONCLUSIONS

The enucleation technique with the use of adjunctive procedures (other than Carnoy's solution) provides a higher recurrence rate than any other treatment modality.

Simultaneous palatal pleomorphic adenoma and mandibular keratocystic odontogenic tumor in a pediatric patient

BACKGROUND

Neoplasms of the salivary gland account for 3% of all head and neck tumors; most of these occur in the parotid gland and are benign; 80% of them are pleomorphic adenomas. Benign neoplasms of the salivary gland are rare in children compared with adults. Keratocystic odontogenic tumor (KCOT) is considered the second most frequent neoplasm of all odontogenic tumors after the ameloblastoma. In the present report, we introduce the unusual presentation of a child with a simultaneous pleomorphic adenoma of the right hard palate and a KCOT of the left mandibular angle.

DISCUSSION

The case is significant for 2 reasons; according to the literature, there are few reports of pleomorphic adenoma arising from a minor salivary gland of the palate in a patient younger than 18 years. This is to our knowledge the first recorded instance of simultaneous palatal pleomorphic adenoma and mandibular KCOT occurring in a child.

Keratocystic odontogenic tumour (KCOT)--a cyst to a tumour

PURPOSE

The World Health Organization (WHO) has reclassified 'odontogenic keratocyst' (OKC) to 'keratocystic odontogenic tumour' (KCOT) in 2005. Currently, this tumour is classified as a benign neoplasm of odontogenic origin and not as a cyst. This article reviews and discusses history, classification scheme, aetiology and pathogenesis, molecular and genetic basis, incidence, epidemiology and site, clinical features, imaging, histopathology, immunohistochemistry, treatment options, prognosis, recurrence and malignant transformation of KCOT, with emphasis on understanding the basis of reclassification as 'keratocystic odontogenic tumour'.

METHODS

A systematic search and review of the literature was carried out in the online database of the United States National Library of Medicine to identify eligible titles for the study.

RESULTS

Current evidence suggests that the scientific community still continues to use the term 'odontogenic keratocyst' more favourably than 'keratocystic odontogenic tumour'.

CONCLUSION

The online database search indicates that the scientific community still continues to use the term 'odontogenic keratocyst' more favourably than 'keratocystic odontogenic tumour'. At this juncture, where the terminology has changed from a cyst to a tumour, a thorough review of literature on KCOT is presented.

Recurrent keratocystic odontogenic tumours: report of 19 cases

OBJECTIVES

The aim of this study was to analyse 19 recurrent keratocystic odontogenic tumours (KCOTs).

METHODS

19 patients with recurrent KCOTs were retrospectively analysed. These patients had been treated by either enucleation or a combination of enucleation and Carnoy's solution. The analyses covered major aspects of primary KCOT and/or recurrent KCOT identities, including patient profile, clinical features, histopathology, radiology, treatment and prognosis.

RESULTS

19 (7.4%) out of 257 primary KCOT cases recurred, with an average patient age of 30.5 years (age range 18-45 years). 15 lesions were in the mandible and the remaining 4 were in the maxilla. There were more unilocular than multilocular occurrences for the primary tumours, with a ratio of 2.2:1. These KCOTs were initially treated by simple enucleation (12 cases) or enucleation with Carnoy's solution (7 cases). After the initial surgery, 15 out of 19 (78.9%) recurred within 6 years, while 4 (21.1%) recurred after 6 years. Evidently, the recurrent lesion was involved with the roots of the teeth in three out of six cases whose teeth were preserved. In addition, the recurrent KCOTs had a tendency to be more multilocular or multifocal than the primary cases, with a unilocular-to-multilocular ratio of 1.1:1.

CONCLUSIONS

7.4% of primary KCOTs recurred within 6 years after initial treatment with either enucleation or a combination of enucleation and Carnoy's solution. The recurrent KCOTs were more likely to be multilocular or multifocal than the primary cases and often involved the teeth. The method of operation for these recurrent lesions would be considered as a more aggressive approach.