Case Of Keratocystic Odontogenic Tumor Research Articles

Keratocystic odontogenic tumor: A case report and review of literature

Keratocystic odontogenic tumor (KCOT) has been identified as a tumor after observation of its biological behavior and genetic abnormalities consistent with neoplastic progression. In 2005, the World Health Organization (WHO) working group considered odontogenic keratocyst (OKC) to be a tumor and recommended the term KCOT, distinguishing the lesion from the orthokeratinizing variant, which is now considered an OKC or orthokeratinized odontogenic cyst. Very rarely, KCOTs can transform into more aggressive lesions such as ameloblastoma and primary intraosseous carcinoma (PIOSCC). In this paper, we present a case of KCOT involving the angle and ramus of the mandible, with histopathologic evidence of ameloblastomatous changes. We also discuss about the evolution of this lesion from a cyst to a tumor along with the latest updates of the entity.

Calretinin as a diagnostic adjunct for ameloblastoma.

Background. Calretinin is a 29 kDa calcium-binding protein of the EF-hand family which is expressed in a variety of normal and tumorigenic tissues. Its expression in odontogenic epithelium during odontogenesis and in neoplastic odontogenic tissues has been demonstrated. Unicystic ameloblastoma poses a diagnostic challenge, as its histologic presentation can be sometimes mistaken for keratocystic odontogenic tumor (KCOT). This study was performed to assess the usefulness of calretinin as a confirmatory marker for ameloblastic tissue. Methodology. Total of 40 cases: 16 unicystic ameloblastoma, 4 multicystic ameloblastoma, and 20 KCOT, were evaluated immunohistochemically for the presence, localization, distribution, and intensity of calretinin expression. Statistical analysis was done using Chi-square test to intercompare the expression between ameloblastoma and KCOT. Results. Sixteen cases of ameloblastoma (12 unicystic, 4 multicystic) showed positive calretinin staining of ameloblastic epithelium and only one case of KCOT was positive for calretinin, with the positivity restricted to the stellate reticulum like epithelium. Intercomparison between two groups revealed statistically significant difference (P = 0.000). Conclusion. Calretinin appears to be a specific immunohistochemical marker for neoplastic ameloblastic epithelium and may be an important diagnostic adjunct in the differential diagnosis of ameloblastoma and KCOT.

Keratocystic odontogenic tumor of the right mandibular condyle: A rare case

Odontogenic keratocyst (OKC) was first described by Hans Philipsen in 1956. The World Health Organization (WHO) has designated OKC as a Keratocystic Odontogenic Tumor (KCOT). KCOT is defined as 'a benign uni- or multicystic, intraosseous tumor of odontogenic origin, with a characteristic lining of parakeratinized stratified squamous epithelium, with a potential for aggressive, infiltrative behavior'. Radiographically, most OKCs are unilocular, presenting a well-defined peripheral rim and a central cavity having satellite cysts. It is characterized by a thin fibrous capsule and a lining of keratinized stratified squamous epithelium, which is typically corrugated, usually about 6 to 10 cells in thickness, and generally without rete pegs. The present case report describes an unusual case of KCOT with minimal clinical presentation indicative of a tumor highlighting the potential difficulties in determining the diagnosis.

Correlation between collagen fibers and radiographic patterns of keratocystic odontogenic tumour.

WHO has recently renamed odontogenic keratocyst as keratocystic odontogenic tumour (KCOT) depending on its tumour like behaviour. To quantitate and qualitate different types of collagen fibers in KCOT using picrosirius red stain under polarising microscopy and to correlate with different radiographic patterns of KCOT to elucidate its biological behaviour in order to determine whether all KCOTs behave like a tumour. Sixty histopathologically confirmed cases of KCOT were selected and stained histochemically using picrosirius red and examined under polarising microscope to evaluate colour of collagen fibers in the wall. Radiographic analysis of all the cases were also carried out and correlated with type of collagen of fibers. Greenish yellow collagen fibers were present statistically significantly more in multilocular KCOT and KCOT with multiple radiolucencies (both syndromic and non-syndromic) as compare to unilocular whereas orange red were significantly more in unilocular variety. Syndromic variety showed significantly higher number of greenish yellow collagen fibers than non-syndromic variety. Quality, organization and packing of collagen fibers of unilocular type is different than other radiographic patterns which accounts for difference in biological behaviour of these lesion, so we conclude that aggressive treatment should be reserved for selected cases.

Keratocystic odontogenic tumor involving the maxillary antrum with displacement of the third molar: A rare case report

Keratocystic odontogenic tumor (KCOT) is a benign intraosseous neoplasm of the jaw with a high rate of recurrence. The lesion commonly occurs in the mandibular molar-ramus area and is rarely seen in the maxilla. Its occurrence in the maxillary sinus along with a displaced third molar is very rare. This article reports a case of KCOT in a 15-year-old boy with a displaced third molar involving the right maxillary antrum.

Expression of perlecan, syndecan-1 and Ki-67 in keratocystic odontogenic tumor

Keratocystic odontogenic tumor (KCOT) is recently considered as one of benign odontogenic tumors due to its unique clinical, histopathological and biological features. In this work twenty cases of keratocystic odontogenic tumor were stained by perlecan, syndecan-1 (CD138) and Ki-67 to study the biological behavior of the tumor. From the results of the study, all the cases of keratocystic odontogenic tumor express perlecan, syndecan-1 and Ki-67. These results concluded that over expression of ki-67 with decrease in perlecan and/or syndecan-1 may be markers for the aggressiveness of keratocystic odontogenic tumor.

Intramuscular keratocyst as a soft tissue counterpart of keratocystic odontogenic tumor: differential diagnosis by immunohistochemistry

Keratocystic odontogenic tumor (KCOT), a developmental jaw cyst previously referred to as odontogenic keratocyst (OKC), typically arises in the jawbone. In this article, however, we report a case of KCOT located within the temporalis muscle. We compared its immunohistochemical profiles with those of authentic jaw KCOT, orthokeratinized odontogenic cyst, and epidermoid cyst in order to consider whether a soft tissue counterpart of KCOT could be a separate disease entity. The patient was a 46-year-old man with a well-defined cystic lesion within the left temporalis muscle. On computed tomographic images, the lesion was recognized as a cystic lesion, although KCOT was not included in the clinical differential diagnoses. The location of the lesion was not within bone but, rather, within the temporalis muscle that was attached to the jawbones. Our review of the literature has disclosed more than 20 peripheral KCOT cases of the oral mucosa and more than 10 cases of the skin, but only 1 case arising in muscle. Immunohistochemical investigation of the present intramuscular case reveals KCOT-characteristic profiles distinct from the other 3 types of cysts investigated. The results indicate that KCOT-like lesions can arise within soft tissues, although use of the term odontogenic might seem inappropriate in those cases.

The expression of cytokeratin in keratocystic odontogenic tumor, orthokeratinized odontogenic cyst, dentigerous cyst, radicular cyst and dermoid cyst

The epithelial lining of odontogenic keratocysts exhibits either parakeratosis or orthokeratosis. In 2005, the WHO classified odontogenic keratocysts with parakeratosis as keratocystic odontogenic tumors (KCOT). Odontogenic keratocysts with orthokeratosis were not classified as odontogenic tumors, but instead referred to as orthokeratinized odontogenic cysts (OOC). To clarify the difference between these two lesions, we investigated their biological characteristics using immunohistochemical studies for cytokeratins (CK) in KCOT and OOC as well as in dentigerous cysts (DC), radicular cysts (RC) and dermoid cysts (DMC). We examined twenty-five cases of KCOT, fifteen cases each of OOC, DC and RC, and ten cases of DMC. We studied the immunohistochemical expression of CK10, 13, 17 and 19. To evaluate the immunohistochemical staining pattern, we divided the epithelial lining of the lesions into three layers (surface layer: su, spinous layer: sp, basal layer: ba). For CK10, most OOC and DMC specimens of su and sp were positive. For CK13 and 19, most KCOT, DC and RC specimens of su and sp were positive. For CK17, most KCOT specimens of su and sp were positive. The percentages of total CK expression of su and sp, and ba of CK19 differed significantly between the lesions (P < 0.001). These results support the hypothesis that OOC originate from not the odontogenic apparatus, but the oral epithelial component.

Integrated Genotypic Analysis of Hedgehog-Related Genes Identifies Subgroups of Keratocystic Odontogenic Tumor with Distinct Clinicopathological Features

Keratocystic odontogenic tumor (KCOT) arises as part of Gorlin syndrome (GS) or as a sporadic lesion. Gene mutations and loss of heterozygosity (LOH) of the hedgehog receptor PTCH1 plays an essential role in the pathogenesis of KCOT. However, some KCOT cases lack evidence for gene alteration of PTCH1, suggesting that other genes in the hedgehog pathway may be affected. PTCH2 and SUFU participate in the occurrence of GS-associated tumors, but their roles in KCOT development are unknown. To elucidate the roles of these genes, we enrolled 36 KCOT patients in a study to sequence their entire coding regions of PTCH1, PTCH2 and SUFU. LOH and immunohistochemical expression of these genes, as well as the downstream targets of hedgehog signaling, were examined using surgically-excised KCOT tissues. PTCH1 mutations, including four novel ones, were found in 9 hereditary KCOT patients, but not in sporadic KCOT patients. A pathogenic mutation of PTCH2 or SUFU was not found in any patients. LOH at PTCH1 and SUFU loci correlated with the presence of epithelial budding. KCOT harboring a germline mutation (Type 1) showed nuclear localization of GLI2 and frequent histological findings such as budding and epithelial islands, as well as the highest recurrence rate. KCOT with LOH but without a germline mutation (Type 2) less frequently showed these histological features, and the recurrence rate was lower. KCOT with neither germline mutation nor LOH (Type 3) consisted of two subgroups, Type 3A and 3B, which were characterized by nuclear and cytoplasmic GLI2 localization, respectively. Type 3B rarely exhibited budding and recurrence, behaving as the most amicable entity. The expression patterns of CCND1 and BCL2 tended to correlate with these subgroups. Our data indicates a significant role of PTCH1 and SUFU in the pathogenesis of KCOT, and the genotype-oriented subgroups constitute entities with different potential aggressiveness.

English

The keratocystic odontogenic tumor (KCOT) is a relatively common oral & maxillofacial lesion that derives its origin from remnants of dental lamina. (1) KCOT represents a special group because of their aggressive growth & recurrence. (2) KCOT's are known for their most aggressive behavior, innate growth potential & tendency to invade adjacent hard & soft tissues causing significant morbidity & mortality. It has a high recurrence rate and is associated with the basal cell nevus syndrome (3) . We hereby report an asymptomatic case of KCOT associated with floating left mandibular third molar resembling an odontome in a 21 years old male patient which was treated by original conservative

Beta-catenin and survivin expression in keratocystic odontogenic tumor (KCOT). A comparative immunohistochemical study in primary, recurrent and nevoid basal cell carcinoma syndrome (NBCCS)-associated lesions.

To determine the epithelial expression of β-catenin and survivin in sporadic (primary, and recurrent) and nevoid basal cell carcinoma syndrome (NBCCS) keratocystic odontogenic tumour (KCOT) in order to assess activation of the β-catenin pathway and evidence of apoptotic inhibition, processes that may contribute to the known differences in their biological behaviour. Sections from 40 cases of KCOT (19 sporadic/primary; 9 sporadic/recurrent and 12 NBCCS-associated) were immunohistochemically stained for β-catenin and survivin. The extent and intensity of immunoreactivity within the lining epithelium was assessed, using semi-quantitative scales, independently by two pathologists who were blinded to the clinical-pathological data. Data were analysed using Kruskal-Wallis test and, for pair-wise comparisons, Mann-Whitney test with Bonferroni correction. All cystic epithelial linings stained for β-catenin and survivin but there were differences in the pattern and intensity of staining among KCOT types. Sporadic primary KCOT showed weaker staining for β-catenin (P=0.0003) and survivin (P<0.0048) that was restricted to the basal and para-basal layers only, compared to sporadic recurrent and NBCCS-associated KCOT, which showed expression throughout all epithelial layers. There were no differences in β-catenin expression among recurrent and NBCCS-associated KCOT, whereas the intensity of survivin staining was higher in NBCCS-KCOT (P=0.0003). Nuclear staining for β-catenin was found exclusively in recurrent (5/9 cases) and NBCCS-associated (4/12 cases) KCOT. The data demonstrate β-catenin delocalization and survivin over-expression in recurrent sporadic and NBCCS-associated KCOT suggesting that these pathways related to apoptotic inhibition have a role in KCOT growth and recurrence.

Diagnostic value of MR imaging for dentigerous cysts

It is known that the magnetic resonance (MR) imaging features of dentigerous cysts (DCs) are the same as those of other cysts. The cavities of DCs generally show low signal intensity (SI) on T1-weighted imaging (T1WI). However, in our experience, DCs often show high SI on T1WI, rendering them difficult to distinguish from keratocystic odontogenic tumors (KCOTs). In this study, we evaluated seven cases of DC and 23 cases of KCOT to assess whether MR imaging can provide additional information for the differential diagnosis of DC and KCOT. Two trials were evaluated. The first trial was an analysis of the cystic cavity SI on T1WI. To compare the SI between patients, we performed T1WI with contrast (T1c). The second trial analyzed the SI uniformity (U Σ) on T1WI, T2-weighted imaging (T2WI), and short inversion time inversion recovery (STIR) images of the cystic cavity, because it has been reported that an MR imaging feature of KCOT is heterogeneous SI. Statistical analyses were performed using the Mann–Whitney U test and a receiver operating characteristic (ROC) curve. The T1c values of DCs were significantly higher than those for KCOTs. The U Σ values on T1WI and STIR images were significantly higher for DCs than for KCOTs. The T1c cutoff values (0.66 and 0.84) and U Σ cutoff values for T1WI (82.1 %) and STIR images (79.8 %) were determined from the ROC analyses. T1c and U Σ values provide useful additional information for the differential diagnosis of DC and KCOT.

Keratocystic Odontogenic Tumor with an Ectopic Tooth in Maxilla

The term odontogenic keratocyst was first used by Philipsen in the year 1956. The lesion was renamed by him as keratocystic odontogenic tumor (KCOT) and reclassified as odontogenic neoplasm in the World Health Organization's 2005 edition that occurs commonly in the jaws having a predilection for the angle and ascending ramus of mandible. In contrast, KCOTs arising in the maxillary premolar region are relatively rare. Here, we discuss a rare case of keratocystic odontogenic tumor occurring in the maxilla with an ectopic tooth position.

Keratocystic Odontogenic Tumour: Current concepts, theory and presentation of 2 contrasting cases.

Odontogenic keratocyst (OKC) is a cyst of tooth origin with an aggressive clinical behavior including a high recurrence rate. It has been rechristened to Keratocystic odontogenic tumour (KCOT), as it better reflects its neoplastic nature. We report 2 contrasting cases of KCOT in association with impacted teeth and revisit the various treatment modalities used to tackle the aggressive nature and keep its recurrence at bay. Most promising being use of molecular biology to treat such tumours which could eventually reduce or eliminate the need for aggressive methods to manage the lesions.

Evaluation of stromal myofibroblasts expression in keratocystic odontogenic tumor and orthokeratinized odontogenic cysts: A comparative study

Objective:Keratocystic odontogenic tumor (KCOT) has an aggressive clinical course and a high tendency of recurrence, while orthokeratinized odontogenic cyst (OOC) has different characteristics and does not show aggressive behaviour. Even the treatment of these two lesions varies considerably. A large number of epithelial molecules have been studied in order to differentiate odontogenic keratocyst (OKC) from OOC, but stromal factors have not been adequately studied. Recently, tumor stroma has evolved as a particular field of interest. In the present study, we aim to evaluate and compare the expression of stromal myofibroblasts (MFs) in these entities and correlate it to its aggressive behavior. The term ‘keratocystic odontogenic tumor’ has been introduced by WHO in 2005 for odontogenic keratocyst keeping in mind its aggressive behavior, however still many pathologists and clinicians use the term OKC synonymously.Materials and Methods:A total of 10 cases of KCOT and 10 cases of OOC were stained for alpha-smooth muscle actin (αSMA) for demonstration of stromal MFs. MF frequency was assessed as the number of αSMA-positive stromal cells in 10 high power fields, presented as the mean number of positive cells per field.Results:Counts showed that the mean number of positive cells in KCOT (20.6 ± 2.05) was significantly higher than that seen in OOC (10.4 ± 1.06) (P < 0.05).Conclusion:The different behaviors of these lesions are compatible with the finding of the present study. The increased number of stromal MFs in KCOT in comparison to OOC correlates with its aggressive behavior and increased tendency towards recurrence.

Keratocystic odontogenic tumor invading the left maxilla: A rare case report

Keratocystic odontogenic tumor (KCOT) is an intraosseous neoplasm of odontogenic origin characterized by high recurrence rates. Commonly, observed in males in second and third decades of life. The aim is to discuss the treatment modalities of a rare case of KCOT in a 5-year-old female child. Considering the age of the patient KCOT was treated by enucleation and Carnoy's solution application to reduce the recurrence and complications associated with repeated surgeries.

Are All Odontogenic Keratocysts Keratocystic Odontogenic Tumors? Correlation between Imaging Features and Epithelial Cell Proliferation

This study was to correlate and analyze the imaging features and epithelial cell proliferation pattern in different cases of keratocystic odontogenic tumors (KCOT) and study the role of inflammation using proliferative markers and different radiographic patterns of KCOT to determine its biological behavior. One hundred and eighty-six cases of KCOT were taken together and grouped based on radiographic patterns. Forty cases were randomly selected and stained using a proliferating cellular nuclear antigen marker. The correlation between imaging and epithelial proliferation with and without inflammation was determined. Unilocular variety is the most common type of KCOT, showing least epithelial proliferation of all the patterns. More than 50% of the multilocular KCOTs were associated with inflammation, showing an enhanced rate of epithelial proliferation. Results were subjected to statistical analysis. Different rates of epithelial proliferation of the different patterns suggested that all odontogenic keratocysts do not behave like tumors and that aggressive treatment should be reserved for selective cases only depending on radiographic and other histopathological parameters such as inflammation.

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

AimTo establish the pattern of occurrence and the clinicopathological features of keratocystic odontogenic tumour (KCOT) over a 10-year period. Materials and methodPatients 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. ResultsA 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. ConclusionBased 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.

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.

Unusual case of keratocystic odontogenic tumor of the maxillary sinus

The term odontogenic keratocyst was first used by Philipsen in 1956. This lesion was recently renamed by him as keratocystic odontogenic tumor (KCOT) and reclassified as an odontogenic neoplasm in the World Health Organization's 2005 edition of its histological classification of odontogenic tumors. KCOT is a benign intraosseous neoplasm of the jaw and its occurrence in the maxillary sinus with an impacted third molar is very unusual. We report a case of KCOT in the right maxillary sinus with an impacted third molar.