Odontogenic cysts, odontogenic tumors, fibroosseous, and giant cell lesions of the jaws

Odontogenic myxoma: A review with report of an uncommon case with recurrence in the mandible of a teenage male

We describe a 13-year-old boy with recurrence of an odontogenic myxoma of the mandible. We review the existing published literature on the lesion, emphasizing the similarities and differences among lesions in the differential diagnosis. Odontogenic myxoma is an uncommon benign tumor that mainly affects the mandible, with a peak incidence in the second to fourth decades of life and predilection for the female sex. Clinical, radiological, and histopathological features should be considered when making a diagnosis. Several of these characteristics overlap with those of other benign and some malignant tumors. Odontogenic myxoma is known for recurrence. The treatment plan should consider the age and sex of the patient and the site and size of the lesion. Reconstructive surgery may be required, but should be delayed until after an adequate follow-up to rule out recurrence.

Diagnosing the most common odontogenic cystic and osseous lesions of the jaws for the practicing pathologist

Odontogenic cysts and osseous lesions are often seen as challenging diagnostic lesions but the majority of them are easily classified. This article outlines the diagnostic features required for separating the most common of odontogenic cysts and select osseous lesions of the jaws. Clinical and radiographic findings of these jaw lesions often lead to a differential diagnosis that only the histologic findings will clarify. Dentigerous cyst, keratocystic odontogenic tumor, and certain ameloblastomas that have cystic change, may have identical radiographic findings, with only separation by their specific histologic features leading to the significantly different treatments required for each. Conversely, some cystic lesions can appear histologically identical and cannot be diagnosed without the radiographic findings. Certain osseous lesions of the jaws are particularly problematic for diagnosis without the appropriate radiographic findings, and the diagnosis should probably not be attempted on the histologic findings alone. This article will integrate the necessary clinical, radiographic, and histologic findings required to address the most common odontogenic lesions.

Establishment and characterization of a cell population derived from a dentigerous cyst

BACKGROUND

Dentigerous cyst (DC) occurs in approximately 20% of jaw cysts, being the second major common odontogenic cyst, after radicular cyst. This oral lesion has the ability to destroy maxillary bones and could be the origin of several odontogenic tumors. However, molecules implicated in its pathogenesis as well as those involved in its neoplastic transformation remain unknown. Here, we established a cell population derived from a DC as an in vitro model for the study of this oral lesion.

METHODS

Cell culture was performed from a DC from a 44-year-old male. Cells were cultured at 37°C in DMEM/F12 medium containing 10% fetal bovine serum. Expression of epithelial markers was analyzed by Western blot and immunofluorescence. Ultrastructural characterization was carried out by transmission electron microscopy. Conditioned media were obtained and characterized by zymography and Western blot.

RESULTS

Cells showed spindle-shaped morphology, but they express epithelial markers, such as cytokeratins and the odontogenic ameloblast-associated protein. The ultrastructural analysis showed well-formed desmosomes present in adhering contiguous cells, confirming the epithelial lineage of this cell population. Cells also contain several vesicles adjacent to plasma membrane, suggesting an active secretion. Indeed, the analysis of the conditioned medium revealed the presence of several secreted proteins, among them the matrix metalloproteinase-2.

CONCLUSIONS

Our work provides a useful model to identify the molecular mechanisms involved in the pathogenesis of DC.

Focal Benign Disorders of the Pediatric Mandible With Radiologic-Histopathologic Correlation: Mandibular Development and Lucent Lesions

OBJECTIVE

Lucent lesions of the pediatric mandible may present variably. Cysts, neoplasms, and developmental and inflammatory conditions have a host of possible causes. There is also substantial overlap in the imaging appearance of cysts and that of benign but locally aggressive tumors that need to undergo resection.

CONCLUSION

The purpose of this article is to present common and uncommon lucent lesions of the mandible in children, with an emphasis on benign abnormalities. Discussions of imaging and histopathologic features are provided.

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

Background

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

Material and Methods

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

Results

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

Conclusions

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

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

A dinosaurian facial deformity and the first occurrence of ameloblastoma in the fossil record

Despite documentation of various types of neoplastic pathologies encountered in the vertebrate fossil record, no ameloblastic tumours have been recognised so far. Ameloblastoma is a benign neoplasic tumour with a strong preponderance for the mandible. Here, we report for the first time the presence of an ameloblastoma neoplasm in the lower jaw of a specimen referred to the derived non-hadrosaurid hadrosauroid dinosaur Telmatosaurus transsylvanicus from the uppermost Cretaceous of the Haeg Basin in Romania. The location, external appearance and internal structure of the pathological outgrowth provide clear evidence for the diagnosis of ameloblastoma in Telmatosaurus. This report extends the range of pathologies encountered in hadrosauroid dinosaurs. In addition, recognition of an ameloblastoma neoplasm in a taxon lying close to the origin of 'duck-billed' hadrosaurid dinosaurs confirms the predisposition of this clade towards neoplasia pathologies already in its basal members.

Glandular Odontogenic Cyst of Mandible: A Rare Entity

Glandular odontogenic cyst (GOC) is a rare developmental odontogenic cyst. It is a slow growing and asymptomatic swelling, usually affecting middle aged men and has tendency to reoccur. Here, we report a case of GOC in the anterior portion of mandible diagnosed by histopathology.

Glandular odontogenic cyst: A diagnostic dilemma

Glandular odontogenic cyst (GOC) is a rare and uncommon jaw bone cyst of odontogenic origin described in 1987 by Gardener et al. as a distinct entity. It is a cyst having an unpredictable, potentially aggressive behavior, and has the propensity to grow in large size with relatively high recurrence rate. It poses a diagnostic challenge as it can be clinically and histopathologically confused with lateral periodontal cyst, botryoid odontogenic cyst, radicular and residual cysts with mucous metaplasia, and low-grade mucoepidermoid carcinoma. The present case report describes GOC in both male and female patients with intra-oral swelling following extraction of 36 and 46, respectively. Careful histopathological examination is needed to diagnose GOC, and a careful long-term follow-up is advocated.

A 5 year retrospective study of biopsied jaw lesions with the assessment of concordance between clinical and histopathological diagnoses

INTRODUCTION

The jaw can be affected by several lesions that manifest in the oral cavity, but little is known about their distribution patterns in various populations.

AIMS AND OBJECTIVES

This study presents the frequency and distribution of biopsied jaw lesions recorded in Faculty of Dentistry and gathers the information including provisional and final diagnosis of the lesions.

MATERIAL AND METHODS

Biopsy of 1938 lesions (2008-2013) was reviewed and 1473 lesions were included in this study. The provisional diagnosis and histopathological validations of lesions were compared. Data on the location of the lesion, as well as patient demographics, were also evaluated. The lesions were divided into three major groups as 1 - developmental/reactive and inflammatory lesions of the jaw, 2 - cystic lesion and 3 - tumor and tumor-like lesions.

STATISTICAL ANALYSIS

The variables were recorded and analysed using descriptive statistics.

RESULTS AND OBSERVATIONS

Three hundred and ninety-six lesions were in Group 1 and periapical granuloma was the most frequent diagnosis. Seven hundred and eighty-nine lesions were in Group 2 and the radicular cyst was the most frequent diagnosis. Two hundred and eighty-eight lesions were in Group 3 and the keratocystic odontogenic tumor was the most frequent. Two hundred and ninety-one biopsied lesions were in disagreement with respect to the diagnoses on clinical and histopathological examination.

CONCLUSION

Consequently, a provisional diagnosis of some of the malignant lesions was reactive, inflammatory, cystic or benign lesions, therefore the importance of evaluation of the specimen is emphasized.

HSP70 expression in dentigerous cyst, odontogenic keratocyst, and ameloblastoma

Heat shock proteins (HSPs) work as molecular chaperones that can assist cells to deal with stressful situations. Members of the HSP70 family can regulate cell growth and transformation and are involved in the maintenance of cellular homeostasis. In view of the distinct clinical behavior of odontogenic lesions, the objective of the present study was to investigate the immunohistochemical expression of HSP70 in these lesions. In this study, 70 formalin-fixed paraffin-embedded tissue blocks of odontogenic lesion-16 unicystic ameloblastomas (UAs), 17 solid ameloblastomas (SAs), 18 odontogenic keratocysts (OKCs), and 19 dentigerous cysts (DCs)-were reviewed by immunohistochemistry for HSP70 staining. In this study, HSP70 immunostaining was evident in all groups of the specimen. Mean percentage of HSP70 staining in SAs (84.2 ± 11.3) and OKCs (83.4 ± 6.8) were significantly higher than UAs (64.4 ± 9.8) and DCs (12.6 ± 10.2) (p = 0.00). But, there was no statistically significant difference between HSP70 expression in SAs and OKCs. The result of this study proposes that high expression rate of HSP70 has a role in the pathogenesis of ameloblastoma and OKC and is one of the reasons for the aggressive behavior of ameloblastoma and high recurrence role of OKC, reinforcing the classification of OKC as an odontogenic tumor.

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.

Expression of Bcl-2 and epithelial growth factor receptor proteins in keratocystic odontogenic tumor in comparison with dentigerous cyst and ameloblastoma

Background:

Keratocystic odontogenic tumor (KCOT) is a developmental odontogenic cyst on which various investigations have been focused due to its biological activities, high tendency to recur and different growth mechanisms in comparison with other cystic lesions. Previous studies have shown different biological and proliferative activities for the lining epithelium of KCOT. The aim of this study was immunohistochemical evaluation of Bcl-2 and epidermal growth factor receptor (EGFR) expression in KCOT compared with dentigerous cyst and ameloblastoma.

Materials and Methods:

Formalin-fixed and paraffin-embedded tissue sections of 16 cases of KCOT, 16 cases of dentigerous cyst and 16 cases of ameloblastoma were immunohistochemically analyzed to determine Bcl-2 and EGFR proteins’ expression. Biotin-Stereotavidin method was used. It was observed by two oral pathologists separately, and the data were analyzed by Mann–Whitney and Kruskul–Wallis. P < 0.05 was considered as significant.

Results:

Regardless of staining intensity, all cases of ameloblastoma and KCOT except dentigerous cases were positively stained for Bcl-2. Expression of Bcl-2 was higher in the peripheral layer of ameloblastoma and basal layer of KCOT. Furthermore, all cases of ameloblastoma and dentigerous cysts except KCOT samples were positively stained for EGFR. Expression of EGFR was higher in the peripheral layer of ameloblastoma and basal layer of dentigerous cysts.

Conclusion:

According to the expression of — Bcl-2 in ameloblastoma and KCOT, and no expression of EGFR in KCOT, it can be concluded that the biological activity and growth mechanisms of KCOT are different compared with other cystic lesions. However, the aggressive potential of KCOT is not as severe as that of a neoplasm such as ameloblastoma.

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.

Congenital adrenal hyperplasia: a case report with premature teeth exfoliation and bone resorption

Congenital adrenal hyperplasia (CAH) is an inherited autosomal recessive disorder characterized by insufficient production of cortisol. The aim of this case report was to present a child with CAH, premature exfoliation of primary teeth and accelerated eruption of his permanent teeth related to bone resorption. A 4.5-year-old Caucasian boy with CAH and long-term administration of glucocorticoids was referred for dental restoration. Clinical examination revealed primary molars with worn stainless steel crowns, severe attrition of the upper canines, and absence of the upper incisors. Before the completion of treatment, abnormal mobility of the first upper primary molars and the lower incisors was detected, and a few days later the teeth exfoliated prematurely. Histologic examination revealed normal tooth structure. Alkaline phosphatase and blood cells values were normal. Eruption of the permanent dentition was also accelerated. Tooth mobility was noticed in the permanent teeth as soon as they erupted, along with bone destruction. Examination revealed an elevated level of receptor activator of nuclear factor-κB ligand and lower-than-normal osteoprotegerin and vitamin D levels. The patient was treated with vitamin D supplements, and his teeth have been stable ever since. CAH is a serious chronic disorder appearing in children with accelerated dental development and possibly premature loss of primary teeth.

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.

Clear cell variant of calcifying epithelial odontogenic tumor: Case report with immunohistochemical findings

Calcifying epithelial odontogenic tumor (CEOT) is a rare benign odontogenic neoplasm, locally aggressive, characterized by sheets and nests of polyhedral epithelial cells exhibiting eosinophilic cytoplasm or less often clear cytoplasm. Additional features include nuclear pleomorphism without mitotic activity, concentric calcifications, and deposits of amyloid. Herein, we present an additional example of clear cell variant of CEOT occurring in a 25-year-old female. Microscopically, the tumor consisted on proliferation of epithelial cells with eosinophilic, clear vacuolated cytoplasm interspersed with focal areas of amyloid deposition. Tumor cells were immunopositive for AE1/AE3, CK14, CK19, β-catenin, CD138, and p63.

Key words:Calcifying epithelial odontogenic tumor, clear cell, histopathology, immunohistochemistry.

Immunoexpression of Ki-67, MCM2, and MCM3 in Ameloblastoma and Ameloblastic Carcinoma and Their Correlations with Clinical and Histopathological Patterns

Cell proliferation assays are performed using antibodies against nuclear proteins associated with DNA replication. These nuclear proteins have gained special interest to predict the biological and clinical behaviors of various tumors. The aim of this study was to analyze the presence of Ki-67 protein and the minichromosome maintenance-2 (MCM2) and maintenance-3 (MCM3) proteins in ameloblastoma. Materials and Methods. Cell proliferation marker expression levels were assessed via immunohistochemistry in 111 ameloblastoma cases (72 unicystic ameloblastoma samples, 38 solid/multicystic ameloblastoma samples, and 1 ameloblastic carcinoma). The label index was performed as described previously. Results. MCM2 and MCM3 showed higher proliferation indexes in all variants of ameloblastoma compared to the classic marker Ki-67. No correlation between the proliferation index and the clinical and protein expression data was observed. Conclusion. The results suggest that clinical features do not directly affect tumor cell proliferation. Moreover, the high levels of cellular proliferation of MCM2 and MCM3 compared with Ki-67 may indicate that MCM2 and MCM3 are more sensitive markers for predicting the growth rate and eventually might be helpful as a tool for predicting aggressive and recurrent behaviors in these tumors.

CD56 Expression in Odontogenic Cysts and Tumors

Background and aims. Odontogenic cysts and tumors have a wide spectrum of clinical characteristics that lead to the different management strategies. Since definite diagnosis is difficult in some cases, it has been suggested that CD56 may be a candidate marker for definitive diagnosis of some odontogenic tumors. The present study was designed to examine CD56 expression in lesions with histopathological similarities.

Materials and methods. In this cross-sectional, analytical study the subjects were 22 ameloblastomas, 13 dentigerous cysts, 10 keratocystic odontogenic tumors (KCOT), 4 adenomatoid odontogenic tumors (AOT), 3 orthokeratinized odonto-genic cysts, 3 calcifying odontogenic cysts (COC) and one glandular odontogenic cyst (GOC). All the samples were examined for CD56 immunoreactivity. Data were analyzed using chi-square test.

Results. Twenty cases (91%) of ameloblastomas, 3 (75%) AOT, 4 (40%) KCOT and one case of GOC were positive for CD56. None of the dentigerous cysts, COC and orthokeratinized odontogenic cysts was CD56-positive. There was a significant difference in the CD56 expression between ameloblastoma and dentigerous cyst, as well as COC. Also, KCOT showed significantly higher expression than orthokeratinized odontogenic cyst.

Conclusion. In this study CD56 expression was limited to the odontogenic tumors and more aggressive cystic lesions. This marker can be a useful aid for distinguishing cysts and tumors from similar lesions.

Immunohistochemical Analysis of Matrix Metalloproteinases-1,-9 and Tenascin in Odontogenic Lesions

Ameloblastoma (ABL) and keratocystic odontogenic tumor (KOT) are benign odontogenic tumors with local aggressive behaviors. The purpose of our study was to compare MMP-1, MMP-9 and tenascin staining patterns between “aggressive” ameloblastoma / keratocystic odontogenic tumors and “non-aggressive” radicular cysts (RC)/ dentigerous cysts (DC). Ameloblastoma, keratocystic odontogenic tumor, radicular cyst (RC) and dentigerous cyst (DC) specimens were chosen from the archives of Gazi University Faculty of Dentistry, Department of Oral Pathology, and immunohistochemically stained with MMP-1, -9 and tenascin antibodies. The immunohistochemical expressions were noted and statistically analyzed. The ABLs and KOTs showed significantly higher MMP-1 and -9 positivity than the RCs and DCs (p<0.05). The ABL and KOT basement membranes showed more continuous tenascin expression. Tenascin intensity was significantly higher in the ABLs and KOTs compared to the RCs and DCs (p<0.05). The results suggest that higher expression of MMP-1 and -9 may play an essential role in the growth and progression of these tumors. Continuous tenascin positivity may reflect strong connective tissue reaction against the invasive epithelial parts of ABLs and KOTs.

Bilateral glandular odontogenic cyst of mandible: a rare occurrence

Glandular odontogenic cysts (GOCs) of the jaw are rare with well-defined limits radiologically, unusual histopathological features and a high recurrence rate. The radiographic appearance of GOCs vary and are not pathognomonic. Definitive diagnosis of the GOC is established only by histopathological examinations. Histologically, GOC is characterized by a thin nonkeratinized squamous epithelial lining, with papillary projections, nodular thickenings, mucous (goblet) cells with intraepithelial mucous pools and intraepithelial glandular, microcystic or duct-like structures. We present an unusual case of a bilateral GOC in the mandible. This case report is also the first documented case of bilateral GOC in the mandible.

The highly prevalent H3F3A mutation in giant cell tumours of bone is not shared by sporadic central giant cell lesion of the jaws

OBJECTIVE

Central giant cell lesion (CGCL) and giant cell tumour (GCT) are bone lesions that share similar microscopic features. Recently, it was reported that 90% of bone GCT exhibit either p.Gly34 Trp or p.Gly34 Leu in H3F3A, one of two genes for histone H3.3 located on chromosome 1. We aimed to test whether sporadic CGCL of the jaws share the H3F3A mutations reported in GCT of other bones.

METHODS

Nine samples of CGCL of the jaws were included in the study, and mutations were assessed by direct sequencing.

RESULTS

None of the CGCL samples presented the recurrent p.Gly34 Trp or p.Gly34 Leu mutations in the H3F3A gene.

CONCLUSION

On the basis of our findings, H3F3A p.Gly34 Trp or p.Gly34 Leu mutations are not a frequent event in CGCL. If these alterations are confirmed to be exclusive of GCT, the assessment of H3F3A mutations may help in the differential diagnosis of GCT and CGCL of the jaws.

Deep Neck Space Infection Caused by Keratocystic Odontogenic Tumor

Keratocystic odontogenic tumor (KCOT) is a benign cystic intraosseous tumor of odontogenic origin. An infection of a KCOT is not common because KCOT is a benign developmental neoplasm. Moreover, a severe deep neck space infection with compromised airway caused by infected KCOT is rare. This report presents a 60-year-old male patient with a severe deep neck space infection related to an infected KCOT due to cortical bone perforation and rupture of the exudate. Treatment of the deep neck space infection and KCOT are reported.

Juvenile ossifying fibroma of mandible: a case report

Fibro osseous lesions are benign mesenchymal skeletal tumours in which mineralized tissue, blood vessels and giant cells, in varied proportions replace normal bone. Included in this group are fibrous dysplasia (FD), cherubism, ossifying fibroma and osteoblastoma. Although fibro osseous lesions have similar histologic and radiographic features, they may exhibit a wide range of biological behaviours. Because the histologic appearance does not predict the rate of growth or prognosis, treatment is based on the clinical and biologic behaviour of the tumour. The term "Juvenile active ossifying fibroma"(JAOF) has been given to a less common, more aggressive variant of the central ossifying fibroma which occurs primarily in children and young adults. This lesion has been described in literature under variety of terms like "aggressive psammomatoid ossifying fibroma" or "juvenile ossifying fibroma". We are presenting a case of Juvenile aggressive ossifying fibroma in a 17 years old girl who reported to our institute.

Benign odontogenic tumors versus histochemically related tissues: preliminary results from mid-infrared and solid-state nuclear magnetic resonance spectroscopy

Three types of human odontogenic tumors histologically classified as compound composite odontoma, ossifying fibroma, and Pindborg tumor were characterized using mid-infrared spectroscopy (mid-IR) and solid-state nuclear magnetic resonance (ssNMR). For comparison, human jawbone and dental mineralized tissues such as dentin, enamel, and dental cement were also characterized. The studies focused on the structural properties and chemical composition of pathological tissues versus histochemically related tissues. All analyzed tumors were composed of organic and mineral parts and water. Apatite was found to be the main constituent of the mineral part. Various components (water, structural hydroxyl groups, carbonate ions (CO(3)(2-)), and hydrogen phosphate ions (HPO(4)(2-))) and physicochemical parameters (index of apatite maturity and crystallinity) were examined. The highest organic/mineral ratio was observed in fibrocementoma, a finding that can be explained by the fibrous character of the tumor. The lowest relative HPO(4)(2-) content was found in odontoma. This tumor is characterized by the highest mineral crystallinity index and content of structural hydroxyl groups. The Pindborg tumor mineral portion was found to be poorly crystalline and rich in HPO(4)(2-). The relative CO(3)(2-) content was similar in all samples studied. The results of spectroscopic studies of odontogenic tumors were consistent with the standard histochemical analysis. It was shown that the various techniques of ssNMR and elaborate analysis of the mid-IR spectra, applied together, provide valuable information about calcified benign odontogenic tumors.

Diagnostic concordance characteristics of oral cavity lesions

Purpose. The objective of this study was to evaluate the diagnostic concordance characteristics of oral cavity lesions by comparing the clinical diagnosis of the lesions with the histopathologic diagnosis. Material and Method. A retrospective analysis was conducted on the patients, who were admitted with oral cavity pathology and underwent biopsy procedure between 2007 and 2011. The oral cavity lesions were classified into 6 different groups as odontogenic cysts, nonodontogenic cysts, odontogenic tumors, nonodontogenic tumors, malignant tumors, and precancerous lesions in accordance with the 2005 WHO classification. The diagnoses were also recategorized into 3 groups expressing prognostic implications as benign, precancerous, and malignant. The initial clinical diagnoses were compared with the histopathologic diagnoses. Data were analyzed statistically. Results. A total of 2718 cases were included. Histopathologic diagnosis did not match the clinical diagnosis in 6.7% of the cases. Nonodontogenic tumors and malignant tumors had the highest misdiagnosis rates (11.5% and 9%, resp.), followed by odontogenic tumors (7.7%), precancerous lesions (6.9%), and odontogenic cysts (4.4%). Clinicians were excelled in diagnosis of benign and precancerous lesions in clinical setting. Conclusion. The detailed discordance characteristics for each specific lesion should be considered during oral pathology practice to provide early detection without delay.

Demographic distribution of odontogenic cysts in Isfahan (Iran) over a 23-year period (1988-2010)

Background:

Odontogenic cysts are relatively common lesions which can cause different complications. As demographic information is lacking in Iran and specially in Isfahan, the aim of this study was to determine the prevalence of odontogenic cysts according to age, gender and affected area among patients referring to the Oral Pathology Department of the Dental School of Isfahan University of Medical Sciences (Iran) over a 23-year period.

Materials and Methods:

A total of 7412 diagnosed lesions recorded in the Oral Pathology Department archives of Isfahan Dental School between 1988 and 2010 were reevaluated, then odontogenic cysts were separated through reviewing microscopic slides according to the 2005 World Health Organization classification and variables such as age, gender, the infected jaw, and its specific region were obtained by SPSS Version 16.0 from the recorded database.

Results:

21.62% of the lesions were odontogenic cysts, of which 48.72% were inflammatory and 51.28% were developmental cysts. These cysts were more common in the mandible. The mean age of patients was 29.53 ± 16.1. Male to female ratio was 1.31:1. The four most frequent odontogenic cysts were radicular cysts (35.12%), dentigerous cysts (25.77%), odontogenic keratocysts (22.58%) and residual cysts (12.98%).

Conclusion:

Odontogenic cysts are fairly frequent jaw lesions (21.62%), of which radicular cyst was the most common cyst. The four most common lesions constituted a sum of 96.45% of the total. In general, the prevalence rates in our study are similar to the studies from other geographic parts of the world but with a lower incidence of inflammatory cysts, higher prevalence of dentigerous cysts and residual cysts and also mandibular predominance for residual cysts.

Radiopaque jaw lesions: an approach to the differential diagnosis

Radiopaque jaw lesions are frequently encountered at radiography and computed tomography, but they are usually underevaluated or underdescribed in radiology reports. A systematic approach to the evaluation of radiopaque jaw lesions is necessary to diagnose the lesion or at least provide a meaningful differential diagnosis. To evaluate a radiopaque jaw lesion, the first, most important step is to categorize the lesion according to its attenuation, its relationship to the teeth, and its location with respect to the tooth. These basic observations are essential to the evaluation of any type of jaw lesion. Once these observations have been made, it is easy to create a proper differential diagnosis. The presence of important characteristics, such as margination, a perilesional halo, bone expansion, and growth pattern, as well as whether the lesion is sclerotic, has ground-glass attenuation, or is mixed lytic and sclerotic, further narrows the differential diagnosis. It is important to note that some radiopaque jaw lesions may be entirely lucent early in their evolution. Awareness of the demographic distribution of these lesions and their associated clinical features, as well as the radiologic approach, is important to explore the "terra incognita" of radiopaque jaw lesions.

Immunophenotypic characterization and distribution of dendritic cells in odontogenic cystic lesions

OBJECTIVE

To analyze the expression and distribution patterns of mature dendritic cells (mDCs) and immature DCs (imDCs) in radicular cysts (RCs), dentigerous cysts (DtCs), and keratocystic odontogenic tumors (KCOTs).

MATERIALS AND METHODS

Forty-nine odontogenic cystic lesions (OCLs) (RCs, n = 20; DtCs, n = 15; KCOTs, n = 14) were assessed using the following markers: S100, CD1a and CD207 for imDCs; and CD83 for mDCs.

RESULTS

Almost all cases were S100, CD1a, and CD207 positive, whereas 63% were CD83 positive. RCs presented greater number of immunostained cells, followed by DtCs, and KCOTs. The number of S100+ cells was greater than both CD1a+ and CD207+ cells (P < 0.001), which showed approximately similar amounts, followed by lower number of CD83+ cells (P < 0.001) in each OCL type. Different from S100+ cells, both CD1a+ and CD207+ cells on the epithelium (P < 0.05) and CD83+ cells on the capsule (P < 0.05) were preferentially observed. In RCs, significant correlation was found between the thickness epithelium with S100+ and CD1a+ cells, and between the degree of inflammation with CD83+ cells.

CONCLUSIONS

Dendritic cell populations in OCLs can be phenotypically heterogeneous, and it could represent distinct lineages and/or functional stages. It is suggested that besides DC-mediated immune cell interactions, DC-mediated tissue differentiation and maintenance in OCLs should also be considered.

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.

Bilateral inflammatory cysts of the jaw: report of an unusual case

Radicular cyst is the most common odontogenic cyst occurring in the jaws. The cyst is commonly found in relation to the maxillary anterior teeth in the third and fifth decade of life. Although multiple radicular cysts are not uncommon in the jaws, bilaterally symmetrical representation of these cysts is rare. Radiographs prior to extraction help in diagnosis of these cysts and thereby prevent further morbidities. We report a case of 16-year-old male patient who presented bilateral radicular cysts symmetrically in the mandible.

EGFR, CD10 and proliferation marker Ki67 expression in ameloblastoma: possible role in local recurrence

Background

Ameloblastoma is an odontogenic neoplasm characterized by local invasiveness and tendency towards recurrence.

Aims

Studying the role played by EGFR, CD10 and Ki67 in the recurrence of ameloblastoma.

Methods

This study was carried out on 22 retrospective cases of mandibular ameloblastoma from the period from Jan 2002 to Jan 2008 with follow up period until Jan 2011 (3 to 8 years follow up peroid). Archival materials were obtained from pathology department, Mansoura university. Paraffin sections of tumor tissue from all cases were submitted for routine H&E stains and immunohistochemistry using EGFR, CD10 and Ki67 monoclonal antibodies. Statistical analysis using of clinical data for all patients, tumor type, EGFR, CD10 and Ki67 expression in relation to recurrence were evaluated.

Results

Among the 22 cases, 10 cases were males and 12 were females with sex ratio 1:1.2. Age ranged from 34 to 59 years old with a mean age 44.18 year. Five cases showed local recurrence within studied period and proved by biopsy. No statistically significant relation was found between local recurrence and patient age, tumor size, tumor type, EGFR expression. There was a significant relation between CD10 expression as well as Ki67 labelling index and recurrence (P value = 0.003, 0.000 respectively).

Conclusion

Evaluation of CD10 and Ki67 status together with conventional histological evaluation can help in providing more information about the biologic behavior of the tumor, while EGFR could be a target of an expanding class of anticancer therapies.

Since ameloblastomas are EGFR-positive tumors, anti-EGFR agents could be considered to reduce the size of large tumors and to treat unresectable tumors that are in close proximity to vital structures.

Virtual Slides

The virtual slide(s) for this article can be found here:

http://www.diagnosticpathology.diagnomx.eu/vs/1902106905645651

Surgical treatment of odontogenic myxoma

BACKGROUND

There is no consensus about the surgical treatment of odontogenic myxoma. The aim of the current study was to present our experience and discuss the surgical management and outcome in 10 patients diagnosed with odontogenic myxoma.

METHODS

A retrospective review of charts of patients who were surgically treated for odontogenic myxoma was performed. Patients were recalled, and eventual recurrences were investigated.

RESULTS

Eight lesions were mandibular, whereas 2 were maxillary. In 3 patients, enucleation and curettage was performed. Instead, in the remaining 7 patients, segmental resection and immediate reconstruction were decided. At follow-up, no patient showed recurrence of the lesion.

CONCLUSIONS

Our protocol is to perform conservative surgery by enucleation and curettage when lesions were smaller than 3 cm, whereas a segmental resection with immediate reconstruction is preferred in patients affected by bigger tumors. Long-term follow-up is required, in particular when conservative surgery is preferred.