Calcifying Odontogenic Cyst Demonstrates Recurrent WNT Pathway Mutations and So-Called Adenoid Ameloblastoma-Like Histology: Evidence Supporting Its Classification as a Neoplasm.

Calcifying odontogenic cyst (COC), once called calcifying cystic odontogenic tumor, is classified under the category of odontogenic cysts. However, the proliferative capacity of the lesional epithelium and consistent nuclear ß-catenin expression raise questions about its current classification. This study aimed to determine whether COC would be better classified as a neoplasm in the histologic and molecular context. Eleven odontogenic lesions diagnosed as COC or calcifying cystic odontogenic tumor were included in this study. The growth patterns of the lesional epithelium were analyzed histologically in all cases. ß-catenin immunohistochemistry and molecular profiling using Sanger sequencing and whole-exome sequencing were performed in 10 cases. Of the 11 cases studied, histologic features reminiscent of so-called adenoid ameloblastoma were observed in 72.7% (8/11), and small islands of clear cells extended into the wall in 36.4% (4/11). Intraluminal and/or mural epithelial proliferation was found in 72.7% of the cases (8/11). Nuclear ß-catenin expression was observed focally in all 10 cases studied, mainly highlighting epithelial cells forming morules and adjacent to dentinoid. CTNNB1 hotspot mutations were detected in 60.0% of the cases (6/10). All the remaining cases had frameshift mutations in tumor-suppressor genes involved in the WNT pathway, including APC and NEDD4L. Recurrent WNT pathway mutations leading to nuclear translocation of ß-catenin and distinct epithelial growth patterns found in COC are the neoplastic features shared by its solid counterpart, dentinogenic ghost cell tumor, supporting its classification as a tumor rather than a cyst.

An unusual presentation of calcifying odontogenic cyst with literature review.

The calcifying odontogenic cyst (COC) is an uncommon developmental odontogenic cyst, the oral counterpart of Malherbe's cutaneous calcifying epithelioma (pilomatricoma). This article presents two unique cases of calcifying odontogenic cysts each exhibiting distinctive histopathological features and its literature review. One case with an unexpected finding of cholesterol granuloma (CG), a rare occurrence in non-inflammatory cysts within an unusual location between two maxillary central incisors. One more instance involves the presence of a compound odontome in conjunction with COC. The cases underscore the clinical and histopathological diversity of COC and highlight the importance of radiological and histopathological assessments for accurate diagnosis. The unexpected association of COC with cholesterol granuloma challenges traditional diagnostic expectations. Additionally, the second case suggests that COCs may warrant sub-categorization to better understand their varied presentations and biological behavior. This article contributes to the expanding knowledge of COC, emphasizing the significance of documenting rare cases to enhance comprehension of its nature, pathogenesis, and oral cavity origin.

Calcifying odontogenic cysts: A novel outlook on classification, diagnosis and management.

BACKGROUND: The Calcifying Odontogenic Cysts (COC) displays a wide range of clinical and histopathological variations as well as diverse biological behaviors. This diversity has led to confusion and disagreement regarding the terminology and classification of this lesion. The previous classification attempts to categorize COC into two concepts. The first concept, termed "monistic," suggests that all COCs are neoplastic despite the majority being cystic in structure and seemingly non-neoplastic. The second concept, known as "dualistic," posits that COC comprises two distinct entities: a cyst and a neoplasm. This research discusses various previous classifications of COC found in the literature and proposes a new, straightforward universal classification based solely on histopathology, aiming to facilitate understanding for surgeons. MATERIAL AND METHODS: Fifteen cases of COC have been collected with clinicopathological parameters including detailed information regarding patient demographics, symptoms, anatomical site, radiological characteristics, duration of evolution, recurrence, and types of histopathology according to the proposed classification. RESULT: A total of fifteen cases of COC were analyzed. According to the histological analysis of the proposed classification Type 1: 5 (33.3), Type II: 4 (26.6), Type III: 3(20), and Type IV:3(20) and recurrence in 3 (20 %) of cases. CONCLUSION: It simplifies the complexities arising from variations in the cystic linings of type IV of COC, which can be overlooked and have caused recurrence in the current research. Therefore, the key requirement for arriving at a validated and practical conclusion lies in the accurate histological classification of calcifying odontogenic cysts and their impact on treatment.

Characterization of stromal calcifications in odontogenic keratocyst: a multicentric study.

Odontogenic keratocysts (OKCs) are locally aggressive cysts that exhibit typical histopathological features and have a propensity for recurrence. Though histological variations are observed in OKCs, hard tissue formation and metaplastic changes are rare, and the underlying pathogenesis is not well understood. This study aimed to characterize stromal calcifications and analyze their association with odontogenic components in non-syndromic and syndrome-associated cases of OKCs. We analyzed 153 cases of OKCs from healthcare institutes in India and Japan. The epithelial and stromal features were evaluated, and the relationship of calcifications with odontogenic rests was determined. Immunohistochemistry for cytokeratin-19 and special stains including Masson Trichrome and Van Gieson, were used for identification of odontogenic rests and calcifications respectively. Stromal calcifications were observed in 29.41% OKCs. The calcification patterns included irregular dystrophic, dentinoid with linear or calcospherite-type mineralization, and psammoma calcifications. Psammoma and dentinoid calcifications were found in the proximity of cytokeratin-19-positive odontogenic rests or satellite cysts, whereas majority cases with dystrophic calcifications did not exhibit co-localization with stromal odontogenic components. Distinct patterns of calcifications were observed in OKCs. Calcifications found in proximity of the odontogenic rests were possibly indicative of an inductive or host-mediated response.

Glandular odontogenic cyst misdiagnosed and treated as a periapical inflammatory lesion for 6 years in an older adult.

OBJECTIVES: To document the case of a patient who underwent several endodontic treatments due to a glandular odontogenic cyst misdiagnosed as an inflammatory periapical lesion. BACKGROUND: Glandular odontogenic cysts behave more aggressively, while others have an indolent course. There is limited information on this cyst in the gerodontologic literature. MATERIALS AND METHODS: A 76-year-old male patient presented with an asymptomatic expansive lesion in the anterior mandible resistant to several endodontic treatments. Cone-beam computed tomography revealed a multilocular osteolytic lesion measuring 6.0 × 4.0 cm, with cortical bone perforation. RESULTS: Histopathological analysis of a biopsy specimen was consistent with glandular odontogenic cyst. The patient underwent marginal mandibulectomy with preservation of the base of the mandible. CONCLUSION: A strict diagnostic process is important to avoid unwanted consequences, particularly in the geriatric population.

CITED1 expression in odontogenic cysts.

BACKGROUND: Originating from odontogenic tissue, Odontogenic cysts are pathological cavities lined with epithelial cells and surrounded by fibrous connective tissue. This study investigated expression of CITED1 protein in different types of odontogenic cysts. MATERIAL AND METHOD: 40 keratocysts, 40 radicular cysts, and 40 dentigerous cysts were excised and processed for routine paraffin wax embedding protocol. Macroscopic and panoramic radiographies images were used for diagnosis. Demographical properties and dental parameters were recorded. Cystic tissues were stained with hematoxylin-eosin dye and CITED1 antibody. Semi-quantitative analysis was performed for immune staining. The protein-protein interaction network, hub gene detection and KEGG analysis were conducted using Cytoscape software. RESULT: Odontogenic keratocysts was imaged with 6-8 layered epithelial cells and fibrous cyst walls with inflammatory cells. Radicular cysts had stratified squamous epithelium with varying thickness, ciliated cells, and Rushton hyaline bodies. Dentigerous cysts presented hyperplastic non-keratinized epithelium, fibrous tissue, rete ridges, and inflammatory cells. CITED1 immunoexpression was highest in odontogenic keratocysts, followed by radicular cysts, and lowest in dentigerous cysts. Nuclear and cytoplasmic CITED1 expression was significantly elevated in odontogenic keratocysts compared to radicular and dentigerous cysts. The top five targets of CITED1 were identified, primarily showing enrichment in hormone and cancer related pathways. CONCLUSIONS: Positive CITED1 expression in all three types of odontogenic cysts suggest a potential role for CITED1 in the pathogenesis of odontogenic cysts, particularly in keratocysts. Further investigations are needed to elucidate the exact mechanisms underlying the differential expression of CITED1 and its implications for the development and progression of odontogenic cysts.

Immunohistochemical expression of SPARC in odontogenic keratocysts: a comparative study with other odontogenic cysts.

BACKGROUND: Secreted protein acidic and rich in cysteine (SPARC) has been shown to modulate aggressive behavior in several benign and malignant tumors. Little is known about SPARC expression in odontogenic keratocyst (OKC), an odontogenic cyst with an aggressive nature. To the best of our knowledge, only one study has been investigated the expression of this protein in OKCs. This study aimed to characterize SPARC expression in OKCs. Additionally, to determine whether SPARC is associated with aggressive behavior in OKCs, SPARC expression in OKCs was compared with radicular cysts (RCs), dentigerous cysts (DCs) and calcifying odontogenic cysts (COCs). These odontogenic cysts showed no or less aggressive behavior. METHODS: SPARC expression was evaluated in 38 OKCs, 39 RCs, 35 DCs and 14 COCs using immunohistochemistry. The percentages of positive cells and the intensities of immunostaining in the epithelial lining and the cystic wall were evaluated and scored. RESULTS: Generally, OKCs showed similar staining patterns to RCs, DCs and COCs. In the epithelial lining, SPARC was not detected, except for ghost cells in all COCs. In the cystic wall, the majority of positive cells were fibroblasts. Compared between 4 groups of odontogenic cysts, SPARC expression in OKCs was significantly higher than those of RCs (P < 0.001), DCs (P < 0.001) and COCs (P = 0.001). CONCLUSIONS: A significant increase of SPARC expression in OKCs compared with RCs, DCs and COCs suggests that SPARC may play a role in the aggressive behavior of OKCs.

[Three-dimensional radiographic features of calcifying odontogenic cyst and calcifying epithelial odontogenic tumor].

OBJECTIVE: To analyze the three-dimensional radiographic characteristics of calcifying odontogenic cyst and calcifying epithelial odontogenic tumor using spiral computed tomography (CT) and cone-beam computed tomography (CBCT). METHODS: Clinical records, histopathological reports, and CBCT or non-enhanced spiral CT images of 19 consecutive patients with calcifying odontogenic cyst (COC) and 16 consecutive patients with calcifying epithelial odontogenic tumor (CEOT) were retrospectively acquired, and radiographic features, including location, size, expansion, internal structure and calcification, were analyzed. RESULTS: Among the 19 COC cases (12 males and 7 females, with an average age of 27 years), 89.5% (17/19) of the lesions originated from the anterior and premolar areas, 100.0% of them exhibited cortex expansion, and 78.9% had discontinued cortex. Among the 16 CEOT cases (3 males and 13 females, with an average age of 36 years), 81.3% (13/16) of the lesions were in the premolar and molar areas, 56.3% of them exhibited cortex expansion, and 96.8% had discontinued cortex. According to the distribution of internal calcifications, these lesions were divided into: Ⅰ (non-calcification type): absence of calcification; Ⅱ (eccentric marginal type): multiple calcifications scattered along one side of the lesion; Ⅲ (diffused type): numerous calcifications diffusely distributed into the lesion; Ⅳ (plaque type): with a ≥ 5 mm calcified patch; Ⅴ (peri-coronal type): multiple calcifications clustered around impacted teeth. Calcifications were present in 73.7% of COC lesions, including 9 type Ⅱ, 3 type Ⅲ and 2 type Ⅳ lesions, and 42.8% of CEOT lesions had calcification images, including 2 type Ⅲ and 5 type Ⅴ lesions. Six COC lesions had odontoma-like images. Moreover, 8 of 9 type Ⅰ CEOTs were histologically Langerhans cell-rich subtype, which had a smaller size (with an average mesiodistal diameter of 17.8 mm) and were not associated with impacted teeth. CONCLUSION: COC lesions tended to originate from the anterior part of the jaw and exhibit cortex expansion, and were sometimes associated with odontoma. CEOT commonly occurred in the posterior jaw and had discontinued cortex. Two lesions had significantly different calcification map. Over 70% of COC lesions had calcification images, which were mostly scattered along one side of the cysts, far from the impacted teeth. Approximately 60% of CEOT lesions exhibited smaller size and non-calcification, and the remaining CEOT cases often had calcification images clustered around the impacted teeth.

Nasopalatine canal cyst, a diagnostic twist.

We present a case of nasopalatine duct cyst in a 35-yearold female. The cyst was diagnosed based on the presence of only one clinical symptom and no obvious clinical signs, which is a relatively rare occurrence. However, the radiographic and histological presentation of this lesion was typical of a nasopalatine duct cyst. Therefore, this case report aims to highlight the variable presentations of the nasopalatine cyst, which is often misdiagnosed and treated as an endodontic infection.

Localization of beta catenin across the domain of odontogenic lesions: A systematic review.

BACKGROUND: CTNNB1 gene encodes beta catenin, a transcriptional activator of Wnt pathway involved in the pathogenesis of odontogenic lesions. Though located intramembranously, its translocation into cytoplasm and nucleus could trigger cell proliferation, inhibition of apoptosis, invasion and migration of the tumour cell. MATERIALS AND METHODS: Five electronic databases including MEDLINE by PubMed, Google scholar, Scopus, Trip, Cochrane library and EMBASE until 1 January 2023 without period restriction were thoroughly searched. Those articles that identified CTNNB1 mutation and beta catenin in odontogenic lesions were included for review. Risk of bias was analysed for each study using QUADAS 2 tool and Review Manager 5.3 was used to output its result. RESULTS: Thirty four published articles were included for data synthesis. A total of 1092 cases of odontogenic lesions were assessed for both CTNNB1 mutation and beta catenin expression. CTNNB1 mutation was observed in ameloblastoma, calcifying odontogenic cyst, calcifying cystic odontogenic tumour and all malignant odontogenic tumours. The beta catenin expression (nuclear and cytoplasmic) was maximum in odontogenic keratocyst and calcifying odontogenic cyst. The expression was variable in ameloblastomas, membranous in odontomas, calcifying cystic odontogenic tumour and nuclear in all malignant tumours. DISCUSSION AND CONCLUSION: High recurrence of odontogenic keratocyst and aggressiveness of solid ameloblastoma and malignant odontogenic tumours could be associated with the nuclear translocation of beta catenin. Disparity between CTNNB1 mutation and beta catenin expression within odontogenic lesions suggests alternate routes of beta catenin activation. The review results support the unique localisation of beta catenin as a helpful diagnostic factor in the pathogenesis of odontogenic lesions.

Pediatric Oral Pathology: Odontogenic Cysts.

Cysts encountered in the head and neck typically arise from epithelium that would normally be programmed to form teeth or tooth-supporting structures (odontogenic epithelium). These cysts come with a confusing array of similar-sounding names and histopathologic features that are sometimes shared between conditions. Here we describe and contrast the relatively-common lesions: hyperplastic dental follicle, dentigerous cyst, radicular cyst, buccal bifurcation cyst, odontogenic keratocyst, glandular odontogenic cyst, and the less-common gingival cyst of the new-born and thyroglossal duct cyst. The goal of this review is to help clarify and simplify these lesions for the general pathologist, pediatric pathologist, and surgeon.

Sociodemographic and clinical characterization of cases of 1,103 non-syndromic and 66 syndromic odontogenic keratocyst: a Brazilian multicenter study.

OBJECTIVES: This multicenter study aimed to evaluate cases of non-syndrome and syndromic odontogenic keratocyst, as well as cases of recurrence within these two groups. METHODS: This descriptive, analytical, retrospective cross-sectional study evaluated the sex, age and presence of multiple lesions in 1,169 individuals seen at 10 Brazilian oral and maxillofacial pathology centers. Of these, 1,341 odontogenic keratocysts were analyzed regarding clinical diagnosis, size, site, imaging appearance, signs and symptoms, type of biopsy, treatment, and recurrence. RESULTS: There was a similar distribution by sex. The median age of non-syndromic and syndromic patients was 32 and 17.5 years, respectively. The posterior mandible was the site most affected by small and large lesions in both groups and in recurrent cases. Unilocular lesions were more frequent, also in recurrent cases. Mainly small lesions showed this imaging appearance. Signs and symptoms were absent in most cases. Conservative treatment was the most frequent modality in all age groups, regardless of the patient's condition and recurrence. Recurrences were uncommon. CONCLUSION: This study showed a higher frequency of non-syndromic keratocysts in the population. Clinicopathological features related to the involvement of multiple sites, age, and recurrence may differ between syndromic and non-syndromic cases. Furthermore, we found an association between lesion size and some clinical features and between the time interval to recurrence and the syndromic spectrum. CLINICAL RELEVANCE: To contribute to a better understanding of the distribution and association between clinical, imaging, and sociodemographic characteristics in each spectrum of the lesion.

Idiopathic bone cavity mimicking a botryoid odontogenic cyst: A rare radiographic presentation in an older adult.

OBJECTIVES: This report describes an unusual case of a multilocular idiopathic bone cavity (IBC) that presented as a botryoid odontogenic cyst situated between the mandibular lateral incisor and canine in an older adult. BACKGROUND: The IBC represents an intraosseous concavity that appears radiographically as a unilocular or multilocular radiolucent lesion found in various skeletal sites, including the jaw. Atypical cases of gnathic IBC have not been appreciated in the gerodontologic literature. MATERIALS AND METHODS: The teeth adjacent to the bony lesion had normal pulpal responses to cold. A full-thickness flap was elevated and provided a direct entry into a bony concavity, which was devoid of an epithelial lining and fluid. RESULTS: The lack of a cystic lining within the empty osseous lesion following surgical entry, concomitant with the vital pulpal status of the proximal teeth, led to a diagnosis of an IBC. The bony walls underwent curettage and copious irrigation prior to primary closure. A 10-month follow-up revealed partial evidence of osseous repair. The patient will continue to be monitored. CONCLUSION: Timely surgical intervention of central lesions of the jaws may improve clinical outcomes. Variants of the IBC should be included in the differential diagnosis of multilocular lesions, particularly in the geriatric population.

The Incidence of Devitalization of Vital Teeth Associated with Pathologies of the Jaws Following Surgical Intervention: A Mixed-case Study.

AIM: The purpose of this mixed-case study is to explore the incidence of pulp necrosis of vital teeth after surgical treatment of adjacent lesions of the jaws. MATERIALS AND METHODS: The records of 341 biopsies submitted to the institute's histopathology laboratory were reviewed to include cases that met the inclusion criteria. About 84 biopsies collected from patients during surgical enucleation of lesions in proximity to healthy vital teeth were included of which 22 patients were recalled. Adjacent teeth were examined clinically and radiographically to assess their pulpal and periapical status after at least 8 months of follow-up. RESULTS: There were 7 different pathological lesions diagnosed histologically. The follow-up period ranged between 8 and 72 months; 12 cases (54.6%) have developed pulpal necrosis for at least one tooth after surgical enucleation of the lesion. The other 10 cases (45.4%) showed normal responses to sensibility testing for all the teeth adjacent to the lesion. Ten out of the 12 cases (83%) that underwent pulpal necrosis were associated with odontogenic cysts, whereas the remaining 2 were associated with periapical granuloma and fibrous dysplasia. CONCLUSION: Pulp necrosis is high in vital teeth associated with lesions without pulpal involvement. These teeth may benefit from root canal treatment prior to surgical enucleation of the lesion, which may prevent impaired healing or recurrence of infection. CLINICAL SIGNIFICANCE: Careful treatment planning and thorough discussion should take place between the surgeons, endodontists, and patients prior to executing the treatment. The patient should be aware that there is a possibility that they may need root canal treatment as a preventative measure to enhance the chances of healing following the surgical procedures and in case the patients opted not to perform root canal treatment beforehand, close follow-up in the future should take place to monitor the vitality of the teeth in the follow-up visits.

RESULTS OF INFLAMMATORY AND IMMUNOLOGICAL PARAMETERS OF THE ORAL CAVITY AFTER CYSTECTOMY WITH DIFFERENT METHODS OF CONNECTING THE EDGES OF THE OPERATED AREA.

OBJECTIVE: The aim: To analyze the results of inflammatory and immunological parameters of the oral cavity after cystectomy with different methods of connecting the edges of the operated area. PATIENTS AND METHODS: Materials and methods: The research was conducted in 87 patients who sought surgical treatment of odontogenic cysts of the jaws. Patients were divided into groups depending on the method of wound closure after surgery. We analyzed the results of laboratory tests (leukocytes, ESR, IL-1ß, IL-6, TNF-α, IL-8, NO synthase, MMP-9). RESULTS: Results: The analysis of the effectiveness of using different methods of approximation of the oral mucosa wound on inflammatory and immunological pa¬rameters showed that when using welding of the edges of the operated area using the EKVZ-300 "Patonmed" apparatus, we get positive results of laboratory indicators of inflammatory markers faster (leukocyte counts are normal on day 30, ESR, IL-1ß - on the 14th day, TNF-α - on the 7th day, IL-6, IL-8, NO synthase, MMP-9 - on the 30th day), that is, healing in such patients is faster than in patients with wound closure with classic suture material or laser. CONCLUSION: Conclusions: When comparing the methods of approximation of postoperative oral mucosa wounds by different methods, based on the results of these inflammatory and immunological parameters, the best results were obtained when using electric welding of tissues. Further research and use of the proposed method will facilitate and shorten the rehabilitation period of patients after surgery.

Hybrid odontogenic lesions: A systematic review of 203 cases reported in the literature.

BACKGROUND: Hybrid odontogenic lesions combine histopathological characteristics of two or more odontogenic cysts and/or tumours. The aim of this study was to evaluate the available data on hybrid odontogenic lesions (HOL) and to analyse their epidemiological/clinical features and biological behaviour. METHODS: An electronic search was done in January 2021 using multiple databases. Eligibility criteria encompassed publications with sufficient clinical and histological information to confirm the tumours' diagnoses. RESULTS: A total of 147 articles were included in this study, comprising 203 cases. Calcifying odontogenic cyst associated with odontoma (COC/OD) (37/18.2%) was the most common HOL. Females were more affected with a mean age of 24.9 years. Lesions presented as asymptomatic swellings, with a mean evolution time of 8.2 months (0.3-96), and mean tumour size of 4.8 cm (0.3-7). Radiographic aspects frequently showed radiolucent (139/68.4%) and unilocular (52/25.6%) images with well-defined limits (48/23.6%). The lesions mostly affected mandibular pre-molars (69/34%) and mandibular molars (69/34%) regions. Enucleation (89/43.8%) and surgical excision (59/29%) were the most common treatment modalities. The mean follow-up time was 33.8 months (0.5-216 months) and recurrences were observed in four cases (1.9%), all of which were central odontogenic fibroma associated with central giant cell granuloma (COF/CGCG). CONCLUSION: COC/OD is the most common HOL and recurrence is a rare event, being usually associated with the diagnosis of COF/CGCG.

Orthokeratinized odontogenic cysts: A clinicopathologic study of 159 cases and molecular evidence for the absence of PTCH1 mutations.

BACKGROUND: Orthokeratinized odontogenic cyst (OOC), a newly designated entity of odontogenic cysts, is an intraosseous jaw cyst that is entirely or predominantly lined by orthokeratinized squamous epithelium. The aim of this study was to report a large series of OOC to substantiate its clinicopathologic profiles and to investigate PTCH1 mutations in OOCs. METHOD: The clinicopathologic features of 167 OOCs from 159 patients were analyzed and the immunohistochemical expression of markers related to cell differentiation and proliferation was evaluated. Furthermore, PTCH1 mutations were analyzed in 14 fresh samples of OOC. RESULTS: OOCs occurred mostly in the third and fourth decades (60.4%) with a male predilection (66.7%). The lesions developed more often in the mandible than maxilla, primarily in the posterior mandible and ramus. Eight patients (5.0%) showed multiple locations of either bilateral posterior mandible (n = 6) or both the maxilla and mandible. Radiographically, the majority of OOCs (91.2%) showed a well-demarcated, unilocular radiolucency with 14 multilocular cases (8.8%). A follow-up of 131 patients (123 treated by enucleation with or without marsupialization and eight by peripheral ostectomy) revealed no recurrence during an average period of 4.56 years after surgery. Immunohistochemistry indicated lower proliferative activity and a varying epithelial differentiation pattern in OOC compared with odontogenic keratocysts (OKC). No PTCH1 mutation was detected, except for three known single nucleotide polymorphisms. CONCLUSION: The clinicopathological and molecular differences between OOC and OKC justified their separation, and unlike OKCs, OOCs did not harbor PTCH1 mutations, suggesting different pathogenesis underlying these two jaw cysts.

Glandular odontogenic cysts: A collaborative investigation of 22 cases and proteins related to invasiveness.

BACKGROUND: A glandular odontogenic cyst (GOC) has an intriguing, aggressive behaviour whose mechanisms have not yet been clarified. OBJECTIVE: To conduct a collaborative cross-sectional study on the clinical, demographic, microscopic and immunohistochemical characteristics of GOCs, emphasizing the histopathological characteristics and expression of proteins related to invasiveness. METHODS: Twenty-two cases of GOC from three oral and maxillofacial pathology services in Brazil were selected from 1988 to 2018. Clinical and demographic data were collected. Histopathological features were evaluated in detail. Sixteen cases of GOC were also submitted to immunohistochemistry to detect MT1-MMP, TKS4, TKS5 and cortactin, the key regulators of invadopodia formation. RESULTS: Glandular odontogenic cysts were primarily seen in men over 40 years of age, in the posterior mandible and the anterior maxilla as a unilocular, radiolucent lesion. All cases presented hobnail cells, clear cells and variable thickness of the lining epithelium, 3 of the 10 key histopathological parameters to be evaluated in GOCs. Immunohistochemistry revealed a greater expression of the studied proteins in the GOCs than in the controls (p < 0.0001). CONCLUSION: Overexpression of proteins that regulate cell invasiveness was identified, and the present study's findings suggest that invadopodia activity is a possible mechanism used by GOCs to promote local invasion, which could partly explain its intriguing biological behaviour.

Primary intraosseous carcinoma in the pediatric and adolescent mandible.

BACKGROUND: Primary intraosseous carcinoma (PIOC) is a rare malignant odontogenic tumor that predominantly occurs in males older than 50 years. PIOC can be misdiagnosed as odontogenic cyst because it occasionally shows a well-defined border on radiography. In this study, related literatures of pediatric and adolescent PIOC cases were analyzed under strict PRISMA guidelines along with an adolescent case who was provisionally misdiagnosed as an odontogenic cyst. METHODS: All case reports for PIOC published in English from 1966 to 2021 were collected. Cases under the age of 20 were classified as pediatric and adolescent populations in this study. A total of 12 pediatric and adolescent cases including 11 PIOCs from the literature and one new case of a 14-year-old female were analyzed. Clinical and radiographic features, diagnosis and treatment approaches, and prognosis were investigated. RESULTS: Ages ranged from 4 to 18 years. The female to male ratio was 1.4:1. Seven cases occurred in the mandible. Swelling was observed in 11 patients. The radiologic borders were well-defined in six cases and corticated in four cases. Tooth displacement and root resorption were observed in four and six cases, respectively. The provisional diagnosis for seven patients was odontogenic cyst and enucleation was performed in six cases including the new case. During the follow-up period, local recurrence occurred in three patients. The pediatric and adolescent PIOC cases with local recurrence showed poor prognosis. The locally recurred lesion in the new case did not decrease in size despite concurrent chemo-radiation therapy. CONCLUSIONS: Three-dimensional imaging modalities and incisional biopsy with multiple specimens are necessary to rule out PIOC in the lesions with atypical radiographic findings. PIOC should be diagnosed differentially from odontogenic cyst even in pediatric and adolescent populations to properly manage the disease with poor prognosis.

Mandibular Buccal Bifurcation Cyst: Report of Two Cases.

Mandibular buccal bifurcation cyst is a rare inflammatory odontogenic cyst. We reported two cases who complained of painful swelling of extraoral soft tissue. Intraoral examination revealed the partially erupted mandibular first molar. Cone beam computed tomography showed a well-defined cystic lesion surrounding the first molar. Histopathologic images showed the cyst wall was infiltrated by a large number of plasma cells, neutrophils and eosinophils, and lined with a thin layer of non-keratinized stratified squamous epithelium. Finally, the two patients were diagnosed as mandibular buccal bifurcation cyst and treated with cyst enucleation and curettage.