Primary intraosseous squamous cell carcinoma arising in an odontogenic cyst: a clinicopathologic analysis of 116 reported cases

Malignant Lesions of the Oral Region

This article focuses on the radiographic presentations of various malignant conditions that affect the oral region and delineates the role of CT, MR imaging, and PET in oral cancer imaging.

Mandibular primary intraosseous carcinoma arising from long-standing odontogenic keratocyst

Primary intraosseous carcinoma (PIOC) of the jaw is a rare neoplasm arising from the lining epithelium of odontogenic cysts or de novo from odontogenic epithelial rests that has no communication with the surrounding mucosa of the upper aerodigestive tract. We present a case of PIOC ex-odontogenic keratocyst (PIOC ex-OKC) in a 35-year-old male. Histopathologic examination revealed a cystic lesion with a fibrous capsule lined by corrugated parakeratinized stratified squamous epithelium resting on a basal cell layer composed of columnar cells exhibiting palisaded hyperchromatic nuclei, features consistent with OKC. Surgical treatment consisted of bilateral crestal and crevicular incision, a reflection of the flap, breaking of all OKC locules, creation of a continuous cavity, and fitting of a decompression mold around the mandibular teeth. This case highlights the importance of knowing the features of PIOC and considering PIOC in the differential diagnosis of malignant tumors of odontogenic epithelium for timely surgical treatment.

A Case of Primary Intraosseous Squamous Cell Carcinoma Arising in Dentigerous Cyst of Mandible

Primary intraosseous squamous cell carcinoma (PISCC) arising from dentigerous cysts (DCs) is rare. Herein, we present a rare case of a 35 year-old Japanese man with PISCC arising from a DC. Clinicians should be aware of the potential for malignant changes to SCC in asymptomatic DCs and should conduct follow-up. Moreover, histological examination of the entire specimen should be performed even if the lesion is suspected to be benign.

Intraosseous carcinoma of the anterior maxilla identified as the occult primary tumour of carcinoma of unknown primary

Carcinoma of unknown primary (CUP) is defined as lymph node metastasis without a detectable origin until after the initial treatment has been performed. The most common occult primary site in the head and neck, as revealed by a review of the published literature, is the oropharynx. An occult primary site in the oral region is extremely rare. We report a rare case of head and neck CUP (HNCUP) in a 69-year-old female patient, wherein the occult primary lesion was a primary intraosseous carcinoma (PIOC) invading the anterior maxilla. During the course of the initial diagnostic workup, no primary lesion could be identified; however, cervical lymph node metastasis to left levels IB and IIA were observed in the patient. A neck dissection followed by adjuvant radiotherapy was performed. However, the PIOC of the anterior maxilla was identified 6 months after neck treatment and was confirmed as the occult primary tumour of the HNCUP. This case is quite rare and required a comprehensive workup to guide optimal treatment. Careful follow-up or active biopsy should be considered if osteolytic changes are observed in the jaw.

Peripheral intraosseous carcinoma arising from a recurrent odontogenic keratocyst

Primary intraosseous carcinoma (PIOC) is a distinct clinical and genomic pathology that should be considered when treating aggressive odontogenic cysts refractory to standard treatments. Odontogenic cysts have a very low chance of malignant transformation, with most studies citing an incidence of <0.05%. The pathogenesis of PIOC is multifactorial, with chronic inflammation-induced carcinogenesis being the most cited theory. Early detection is imperative to enhance the patient's prognosis, with the 5-year overall survival rate of PIOC being 38%. This paper presents a case of PIOC and reviews data on its epidemiology, diagnosis, presentation, and treatment.

Primary Intraosseous Squamous Cell Carcinoma of the Mandible Mimicking Inflammation on FDG PET/CT

ABSTRACT

Primary intraosseous squamous cell carcinoma (SCC) is an uncommon malignant cancer involving the jaw bones. We herein reported the imaging findings of a primary intraosseous SCC of the mandible in a 47-year-old man. He was diagnosed as cancer of unknown primary in the cervical node. FDG PET/CT revealed a focal hypermetabolic lesion around the tooth root of the right lower molar. MRI showed the lesion had hyperintensity on T2-weighted imaging and significant enhancement on T1-weighted imaging fat saturate images. The final diagnosis of primary intraosseous SCC of mandible was confirmed pathologically.

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.

Critical assessment of the latest classification of jaw cysts proposed by the World Health Organization (2017)

Background

The fourth edition of the World Health Organization Classification of Head and Neck Tumors was published in January 2017, and includes a classification of odontogenic tumors and odontogenic cysts. The present review assesses the changes made in this new classification in relation to odontogenic and non-odontogenic jaw cysts.

Material and Methods

An electronic search was conducted in the Cochrane Library, PubMed-MEDLINE and Scopus databases using the search terms: “odontogenic cyst” “WHO classification” “update”. Studies written in English and published between January 2005 and April 2020 with a high level of scientific evidence were included, while studies not published in English, epidemiological studies, and studies with a low level of scientific evidence were excluded.

Results

The initial search identified 311 articles, and after the deletion of duplicates, 7 studies were selected for full-text assessment. After excluding two studies that failed to provide relevant information and had a low level of scientific evidence, 5 articles were finally included and stratified according to their level of scientific evidence based on the SORT (Strength of Recommendation Taxonomy) criteria.

Conclusions

The incorporation of odontogenic and non-odontogenic cysts to the head and neck tumors classification underscores the recognition of the WHO of these important disorders of the jaws. Based on the current evidence, there is controversy as to whether odontogenic keratocysts should be regarded as cystic lesions or as neoplasms, though there is no such controversy in relation to calcifying odontogenic cysts. On the other hand, orthokeratinized odontogenic cysts have been included in the classification as a single entity differentiated from odontogenic keratocysts, while residual cysts have been removed from the classification.

Key words:Odontogenic cyst, WHO classification, pseudocyst.

Malignant Odontogenic Tumours: A Systematic Review of Cases Reported in Literature

Background: Malignant odontogenic tumours (MOTs) arise either de novo from the tooth forming tissues, their developmental residues or from existing odontogenic epithelial or mesenchymal neoplasms in the jaws. Their management requires extensive surgery due to their infiltrative nature and risk of metastasis. There is a need to understand the clinical and pathological features of MOTs to inform both treatment algorithms and prognostication. This is an area of diagnostic pathology which presents substantial difficulties in diagnosis, compounded by inconsistent use of terminology. Thus, this systematic review aimed to describe the clinical and pathological features of MOTs with a view to consolidating the literature and defining problematic areas in diagnosis and classification. Methods: An electronic database search was conducted in Web of Science, PubMed/Medline, and Embase. Additionally, the grey literature and reference lists of selected papers searched for completeness. Nine hundred and sixty articles were initially identified. Following removal of duplicates and application of inclusion/exclusion criteria, 312 articles were included for qualitative analysis. Results: The 312 articles encompassed a total of 507 patients with most lesions located within the mandible (74.3%). The most common first histological diagnosis was ameloblastic carcinoma (25.7% of all diagnoses), but there is considerable variation in how and when various diagnostic terms are used, and several misdiagnoses were reported. An initial benign diagnosis was made in 24.7% of patients, followed by a later malignant diagnosis and in this sub-group, the most common benign first diagnosis was ameloblastoma (42.4%). Cervical lymph nodes were the most common site of metastasis (9.3% of patients). With respect to distant metastasis (DM), the lungs were the most common organ affected (11.2% of DM patients) with metastasising ameloblastoma the most commonly reported tumour which metastasised to the lungs. Overall, 26.8% of patients developed recurrence. Conclusion: Overall, the quality of the literature on MOTs is poor. This review of the literature has highlighted variations in diagnostic terms and criteria which has resulted in areas of confusion with potential for misdiagnosis. This consolidation of primary data has identified key areas for targeted research including further discussion on the malignant potential of ameloblastoma.

Revisiting the human dental follicle: From tooth development to its association with unerupted or impacted teeth and pathological changes

Dental follicles are involved in odontogenesis, periodontogenesis, and tooth eruption. Dental follicles are unique structures, considering that their remnants can persist within the jawbones after odontogenesis throughout life if the tooth does not erupt. Pathological changes may occur in these tissues as individuals age. The changes range from benign to life threatening. Thus, the assessment of age-related changes in dental follicles associated with unerupted teeth is of paramount importance. In this review, we summarize the physiological roles and changes in dental follicles in odontogenesis, tooth eruption, and aging, in addition to the pathological changes associated with these structures. We encourage investigators to consider this peculiar tissue as a unique model and explore its potential to clarify its importance from the viewpoints of developmental biology, tissue physiology, and pathology.

Orthokeratinized odontogenic cyst: A large series and comprehensive literature review with emphasis on synchronous multiple occurrence and neoplastic transformation

OBJECTIVES

The objective of this study was to demonstrate the clinical, radiologic, and histologic features of orthokeratinized odontogenic cyst (OOC); determine the characteristics of multiple OOCs; and present rare but significant manifestations of OOC.

STUDY DESIGN

A clinical, radiologic, and histopathologic study of 65 primary and 2 recurrent OOC cases was performed retrospectively along with a comprehensive literature review.

RESULTS

OOCs shared similar radiologic findings with odontogenic keratocyst, yet some showed features that have not been previously described: root resorption and radiopaque foci. Histologic review revealed a unique histiocytic lining and some findings suggestive of the multipotentiality of the odontogenic epithelium. The analysis of patients with multiple OOCs demonstrated that multiple OOCs occurred synchronously with a marked predilection for young male adults. Two unusual cases were also identified: an OOC combined with a BRAF^V600E ameloblastoma and a recurrent OOC with malignant transformation.

CONCLUSIONS

This largest series presents previously unreported radiographic and histopathologic features that can be seen in OOC. Multiple OOCs have clinical characteristics distinct from those of solitary cases. The first reported OOC associated with ameloblastoma suggests the involvement of oncogenic mutations in odontogenic tumorigenesis. Although OOC shows a low recurrence rate, the possibility of malignant transformation of recurrent OOCs should be emphasized.

What factors differentiate dentigerous cysts from other pericoronal lesions?

OBJECTIVE

To evaluate the histopathologic outcomes of pericoronal radiolucencies and identify factors predictive of diagnosis.

STUDY DESIGN

A retrospective cohort study of 258 patients with 280 radiolucent pericoronal lesions undergoing treatment at our institution between 2005 and 2019. The primary predictor variable was lesion size (≥2 cm and <2 cm). The primary outcome variable was histopathologic diagnosis (dentigerous cyst vs other pathologic entity). Descriptive, bivariate, and multiple logistic regression statistics were computed to measure the association between clinical and radiographic variables and histopathologic diagnosis.

RESULTS

The study sample was composed of 258 patients with 280 histopathologic specimens. There were 218 dentigerous cysts (77.9%) and 62 other pathologic entities (22.1%). Lesions ≥2 cm were 3.20 times more likely to be diagnosed as a nondentigerous cyst pathologic entity (P ≤ .001). After adjusting for jaw (maxilla vs mandible), pain, history of infection, cortical perforation, expansion, and multiple lesions, younger age (P ≤ .001, odds ratio [OR] = 0.950, 95% confidence interval [CI] = 0.929-0.972) and lesion size as a continuous variable (P = .007, OR = 1.06, 95% CI = 1.02-1.11) were independent predictors of other pathologic entities.

CONCLUSIONS

The majority of pericoronal radiolucent lesions were dentigerous cysts. Younger age and larger lesions were independent predictors of other pathologic entities.

Sequential treatment from mandibulectomy to reconstruction on mandibular oral cancer - Case review I: mandibular ramus and angle lesion of primary intraosseous squamous cell carcinoma

Primary intraosseous squamous cell carcinoma (PIOSCC) is very rare type of squamous cell carcinoma (SCC) that occurs within the jaw and arises from remnants of odontogenic epithelium with no connection to the oral mucosa. This study reports two cases of PIOSCC of the mandible. Reported in this article are two cases of PIOSCC of the mandible that were treated with resection and reconstruction using a fibular free flap. The first case was a 36-year-old male patient who complained of right mandibular pain. Computed tomography (CT) and panoramic radiograph revealed a large radiolucency in the mandibular ramus area. At first, an odontogenic keratocyst was tentatively diagnosed, and an excision procedure was carried out at another clinic. A final biopsy after cyst enucleation revealed well-differentiated SCC, so we proceeded with segmental mandibulectomy and reconstruction using a fibular free flap. The second case was a 48-year-old male patient with left mandibular pain. CT and panoramic radiograph revealed irregular radiolucency in the mandibular angle area near tooth #38. At first, osteomyelitis was tentatively diagnosed, and a curettage was carried out. A later biopsy revealed well-differentiated SCC, so segmental mandibulectomy and reconstruction with a fibular free flap were secondarily performed. Our two cases have had no recurrence. The facial appearance of both patients is satisfactory, and the neo-mandibular body created using a fibular bone transfer displays adequate bony volume.

Sine Qua Non: Dentigerous Cyst

Dentigerous cysts, also known as follicular cysts, are among the most common developmental cysts of the gnathic bones. The majority of cases are clinically asymptomatic and discovered incidentally on panographic radiographs during routine dental care. The cyst appears as a radiolucency, classically unilocular, associated with the crown of an unerupted or impacted tooth. Usually diagnosed in the 2nd-3rd decade, third molars of the mandible are the most commonly affected teeth. Histologically, dentigerous cysts demonstrate a fibrous or fibromyxoid connective tissue wall lined by squamous epithelium, classically lacking rete ridges. Inflammation may introduce histologic changes, however. The differential diagnosis includes hyperplastic dental follicle, periapical or radicular cyst, unicystic ameloblastoma, odontogenic keratocyst, and other odontogenic cysts and tumors. While the findings are generally classic and pose no diagnostic dilemma, the diagnosis is best made in the context of the appropriate clinical and radiographic setting. Submitted tissue with a lack of history, to include a detailed relationship with the affected tooth, may result in misdiagnosis and subsequent confusion for the clinician. So, despite its simple features, dentigerous cysts are not uncommonly mischaracterized. Therefore a review of a classic case of dentigerous cyst is presented.

Clinico-pathological study of malignant odontogenic tumours from a national referral centre

BACKGROUND

Malignant odontogenic tumours are extremely rare tumours occurring within the jaws. Our study was performed to determine the demographic and clinico-pathological features of malignant odontogenic tumours amongst a multi-ethnic Asian population.

METHODS

This was a retrospective cross-sectional study of malignant odontogenic tumours diagnosed at the Institute for Medical Research, Malaysia, from 2009 to 2019. All cases were independently reviewed and reclassified following the criteria set out in the latest edition of the World Health Organization 2017 reference text. Demographic and clinico-pathological data were recorded for each case.

RESULTS

Twenty-four cases of malignant odontogenic tumours were identified. The patients' age ranged from 16 to 79 years with the mean age at diagnosis being 50.8 years (SD = 16.18). There was a male predominance (66.7%) in this cohort of patients. The ethnic distribution appeared to reflect the Malaysian population with most cases seen amongst the Malay ethnic group (66.7%). Ameloblastic carcinoma was the most frequently diagnosed malignant odontogenic tumour (45.8%) and was also predominantly seen in males (90.9%). All patients with clear cell odontogenic carcinoma were females. There was no obvious sex predilection in primary odontogenic carcinoma not otherwise specified (NOS). The mandible (79.2%) was more frequently involved compared to the maxilla.

CONCLUSIONS

Diagnosis and management of malignant odontogenic tumours are challenging due to the rarity of these tumours. Our study has elucidated the clinico-pathological features of malignant odontogenic tumours seen in a multi-ethnic Asian population.

Primary intraosseous malignancies: A 10-year retrospective cohort study

OBJECTIVE

This study aimed to explore the characteristics and prognoses of primary jaw malignancies and identify valuable prognostic factors.

STUDY DESIGN

Patients who were primarily diagnosed with jaw malignancies at Beijing Stomatological Hospital between 2006 and 2016 were retrospectively reviewed.

RESULTS

Eighty patients with malignant jaw tumors were enrolled in the study. Squamous cell carcinoma was the most common type (56.2%). The age range of patients varied from 11 to 92 years old (mean age = 51.5 years), and the male-to-female ratio was 2.1:1. Anatomically, the mandible was involved in 82.5% of cases. The estimated disease-free survival and overall survival (OS) rates were 60.6% and 73.2%, respectively. Cox multivariate analysis showed that a smoking history (hazard ratio = 5.015, 95% confidence interval, 1.900-13.235, P = .001) and advanced age (≥60 years; hazard ratio = 2.464, 95% confidence interval, 0.987-6.155, P = .046) were independent prognostic factors for poor OS.

CONCLUSION

Primary jaw malignancies were more prevalent in the mandible and among males and middle-aged patients. Radical resection of the primary surgery was the basis of a good prognosis, and the choice of postoperative adjuvant therapy may not ultimately affect OS. Patients with a history of smoking and advanced age were at high risk for poor prognosis.

Primary nonkeratinizing squamous cell carcinoma of the scapular bone: A case report

BACKGROUND

Squamous cell carcinoma (SCC) of bone is usually caused by metastasis from the lungs, bladder, or other sites. Primary SCC of bone most frequently involves the skull bones, and primary involvement of other sites in the skeletal system is extremely rare. To date, only three such cases have been reported, which makes the diagnosis, treatment, and prognosis of this disease a challenge.

CASE SUMMARY

A 76-year-old Chinese man presented to our hospital with nonspecific pain and limited mobility in the right shoulder for 4 mo. He underwent three-dimensional computed tomography reconstruction and magnetic resonance imaging of the right shoulder, which revealed an osteolytic destructive lesion in the right scapula with invasion into the surrounding muscles and soft tissues. Ultrasound-guided core needle biopsy detected a malignant tumor, and immunohistochemical analysis revealed a poorly differentiated SCC. Wide excision of the right scapular bone was performed, and pathological examination of the surgical specimen confirmed the diagnosis. At the last follow-up examination within 2 years, the patient was doing well with the pain significantly relieved in the right shoulder.

CONCLUSION

Primary SCC of bone is extremely rare at sites other than the skull. Clinicians must exhaust all available means for the diagnosis of primary SCC of the bone, so greater attention can be paid to its timely and effective management. Regular and adequate follow-up is essential to help rule out metastasis and judge the prognosis.

Primary intraosseous squamous cell carcinoma arising from an odontogenic keratocyst: case series and literature review

Background

The aim of this study was to investigate the clinicopathologic features of primary intraosseous squamous cell carcinoma arising from an odontogenic keratocyst (PIOSCC ex OKC) and comprehensively improve the understanding of this disease.

Material and Methods

We retrospectively investigated five cases of PIOSCC ex OKC at Peking University School and Hospital of Stomatology. We also conducted a systematic review of studies on PIOSCC ex OKC by using online databases from their inception until February 2020.

Results

In our series of five cases, all lesions were located in the mandible. Three cases (60%) showed recurrent OKCs and two cases (40%) showed primary OKCs. During the follow-up period, one patient died of local relapse. No patients developed metastasis. On the basis of our literature survey, we selected 22 articles reporting 29 patients with PIOSCC ex OKC. Seven of these patients (24.1%) showed local recurrence, three patients (10.3%) developed cervical metastasis, three patients (10.3%) developed distant metastasis (in the pleura in one case and in the lung in two cases), and seven patients died from the disease during the follow-up period. The disease-specific 5-year survival rate in the study group was 53.2%. Through univariate and multivariate analysis, local recurrence was identified as the only significant independent prognostic factor for survival (P < 0.05).

Conclusions

The results suggest that PIOSCC ex OKC is a rare intermediate-grade malignancy. Although elective neck dissection is typically unnecessary, adequate therapy should be applied to achieve the lowest local recurrence rate possible to ensure a favorable survival rate.

Key words:Primary intraosseous squamous cell carcinoma, odontogenic keratocyst, prognosis.

Carcinomatous Transformation of Odontogenic Keratocyst and Primary Intraosseous Carcinoma: A Systematic Review and Report of a Case

PURPOSE

To assess the prognostic findings of the carcinomatous transformation of odontogenic keratocyst (OKC).

METHODS

A systematic review of all cases of carcinomatous transformation of OKC was completed, and a case report was included.

RESULTS

A total of 679 publications were screened, and 37 cases met inclusion criteria. The mean age for patients with malignant transformation of OKC was 45.1 years. Pain (67.5%) and swelling (78.3%) were the most common symptoms. The malignant transformation occurred with increased frequency in the posterior mandible and larger lesions that span greater than 2 subunits of the involved jaw. Resection was the definitive treatment in all cases and 14 cases (46%) utilized adjuvant treatment.

CONCLUSIONS

Patient outcomes and follow-up was variable in our study such that overall survival was difficult to determine. However, overall survival in malignant transformation of odontogenic cysts of all kinds ranges from 62 to 85% and 30 to 8% for 2 and 5 years, respectively.

Residual cyst of the jaws: A clinico-pathologic study of this seemingly inconspicuous lesion

OBJECTIVES

Residual cysts are relatively rare inflammatory cysts of the jaws. They are essentially radicular cysts without the presence of the offending dentition. These lesions have the ability to destroy bone within the jaws without any symptoms. Moreover, they can mimic more aggressive cysts and tumours on radiographs. The aim of this study was to describe the clinico-pathological features of residual cysts in order to discern them from other cystic lesions as well as analyse their management and recurrence patterns.

MATERIALS AND METHODS

Sixty-four histopathologically confirmed residual cysts were analysed based on their clinical, radiological and histopathological features. Their management and follow-up were also noted.

RESULTS

The majority of lesions presented in elderly (46.8%), edentulous patients (60.9%) and were most commonly found in the posterior regions of the mandible (51.6%). Clinico-pathological features that aided in their diagnosis included long-standing history with slow growing swelling and presence of well-defined, unilocular cystic lesion associated with previously extracted dentition. Enucleation was a successful method in the management of residual cysts with very low recurrence rate (1.6%). Two patients (3.1%) developed squamous cell carcinoma from the cyst lining.

CONCLUSION

Residual cysts should be high on the list of differential diagnosis when elderly, edentulous patients present with cystic lesions in the jaws compared to dentate patients (P<0.01). All lesions should by biopsied and sent for histopathological examination along with radiological correlation as they have the potential to transform into primary intra-osseous squamous cell carcinoma with devastating consequences to the patient.

Primary intraosseous squamous cell carcinoma ex-odontogenic cyst

Squamous cell carcinomas of the oral cavity are quite common, but primary intraosseous squamous cell carcinomas (PIOSCCs) are rare. Their origin from lining of different odontogenic cysts has been documented. More than 50% of such cases have been reported to occur in periapical inflammatory cysts, and less than 10 cases are reported to arise from odontogenic keratocyst (OKC). One such rare case of a PIOSCC, which presented as an OKC initially, is being reported.

Primary intraosseous carcinoma arising in dentigerous cyst: Case report

•

Primary intraosseous carcinoma arising in a dentigerous cyst is a rare observation.

•

There are no clinical or radiological pathognomonic characteristics and the diagnosis is often made fortuitously.

•

A surgical excision with clear margin is the cornerstone of treatment.

•

A systematic and careful microscopic analysis of any cyst, even if look like benign, should be undertaken.

Introduction

Carcinomas arising in odontogenic cysts are uncommon. Malignant transformation of a dentigerous cyst is a rare observation. A primary intraosseous carcinoma from a dentigerous cyst in a 69 years old female is presented in this case report.

Presentation of case

The patient initially consulted for pain in the mandibular left molar region. Primary investigations firstly showed a probably benign lesion but immunochemistry analysis finally revealed a squamous cell carcinoma arising in a dentigerous cyst. An extension assessment was performed and no evidence of lymph node extension or distant metastasis were found. A non-interrupting mandibular bone resection without neck dissection was realized. The patient made a good recovery after surgery without postoperative complication. No clinical symptoms or sign of local recurrence or metastasis was detected after 17 months follow-up.

Discussion

PIOC arising in a dentigerous cyst is a rare observation. PIOC from odontogenic cysts have an incident rate of 0,3 to 2% and only 16%–51% of them are PIOC from dentigerous cyst. There are no clinical or radiological pathognomonic characteristics. They often look like benign lesion and the diagnosis is often made fortuitously. A surgical excision with clear margin is the cornerstone of treatment. Clinical and radiological follow-up of the patient is recommended.

Conclusion

This case underlines the importance of a systematic and careful microscopic analysis of any lesion, even benign at first sight. Surgeons and pathologists should be aware of the malignant potential of odontogenic cysts. This can modify the surgical management and the follow-up of the patient.

Primary Intraosseous Squamous Cell Carcinoma Involving the Jaw Bones: A Systematic Review and Update

Primary intraosseous oral squamous cell carcinoma (PIOSCC) is a rare malignant neoplasm that affects the jaws. Despite its aggressive biological behavior, there are no studies that evaluated the clinicopathological features of this tumor and parameters associated with its prognosis. The objective of the present study was to conduct a systematic review of the available data on oral and maxillofacial PIOSCC in order to determine its clinicopathological characteristics and biological behavior. We conducted a systematic review in May 2020 in multiple databases using a specific search strategy. Cases diagnosed as PIOSCC in the oral cavity and maxillofacial complex that had sufficient histopathological data, absence of ulceration in the oral mucosa, a negative result for a distant primary tumor, and radiographic evidence of an osteolytic lesion that was entirely or mostly surrounded by the jaw bones were included. A total of 109 published articles were included in our systematic review, corresponding to 257 cases. PIOSCC showed a male predilection (69.3%) and a preference for the mandible (7:1), with the posterior region being the most commonly affected site. The mean age at diagnosis was 57.3 years. Cortical expansion, pain, and lip/facial paresthesia were the most common clinical features. Regarding histopathological features, most PIOSCC were well-differentiated and the solid subtype was the most common. Statistical analysis showed that PIOSCC located in the mandible (p = 0.03) and recurrence (p < 0.01) were significantly associated with a higher mortality rate. PIOSCC has a poor prognosis, with high rates of mortality.

Malignant Lesions Mimicking Endodontic Pathoses Lesion: A Systematic Review

INTRODUCTION

Malignant nonendodontic periapical lesions represent a rare diagnosis, in which few case have been reported about this condition. Due to the low occurrence and little exploration of this subject, serious errors of diagnosis are observed in the oral medicine services. In this sense, the purpose of the present review was to integrate the information on the record published on malignant lesions that mimic endodontic pathoses into a comprehensive analysis of their clinical, radiologic, and histopathologic features.

METHODS

An online search was made in March 2020 in the following databases: Pubmed, Web of Science, and Scopus. Eligibility criteria included publications having enough clinical, radiologic, and histopathologic information to confirm the diagnosis. Data were assessed descriptively.

RESULTS

Forty-nine publications from 16 countries comprising 60 cases were included. There is a nearly equal occurrence rate between males and females (male/female ratio is 49.15%/50.84%) with a mean age of 46.56 years. The lesions were more prevalent in the posterior mandibles (40.69%), and, radiographically, they were unilocular radiolucent. Histopathologic analysis showed metastasis (26.67%) as the most prevalent lesion followed by salivary gland malignant disease (25%).

CONCLUSIONS

The present systematic review revealed several histologic types of malignant periapical lesions that could be mimicking endodontic pathoses. Because these lesions usually do not show clinical or radiologic features of malignant alteration, clinicians should consider these hypotheses in their routine.

Effects of aging on DNA hydroxymethylation and methylation in human dental follicles

OBJECTIVE

Despite the high frequency of impacted teeth and increased frequency of lesions in dental follicles (DF) with aging, DF age-changes remain unclear. We compared the global methylation and hydroxymethylation profiles in DF in relation to age.

DESIGN

DF associated with impacted lower third molars were obtained from 59 individuals. Global DNA methylation (5mC content) and hydroxymethylation (5hmC) were evaluated by ELISA. We tested the correlation between 5mC and 5hmC content, and the correlation of each with patients' age. The differences in age, 5mC, and 5hmC in DF from men/women, and location (left/right mandible) was tested.

RESULTS

The mean age of the 59 individuals was 19.56 ± 3.92, ranging from 13 to 31 years, and most were women (n = 39). 5hmC content and age up to 19 years were inversely correlated (Spearman's correlation coefficient=-0.552, p = 0.0003, n = 38). There was no relationship between 5hmC and 5mC content. There was no difference in the medians of age (p = 0.25), 5hmC (p = 0.33) and 5mC (p = 0.86) between men/women, nor in the medians of age (p = 0.39), 5hmC (p = 0.99) and 5mC (p = 0.22) between the left/right side of the tooth extraction.

CONCLUSION

An inverse correlation between 5hmC and age was established, with no correlation between 5mC and 5hmC content in DF. The biological meaning of such a decrease of global DNA hydroxymethylation with age in DF remains to be clarified.

Complete removal of dentigerous cysts with preservation of associated teeth as an alternative to marsupialization in children and preadolescents

The aim of this study is to evaluate the results of dentigerous cysts enucleation with preservation of cyst-associated teeth as a single procedure in a group of children and preadolescents. A retrospective case series of seven patients with 15 unerupted developing teeth associated with or adjacent to dentigerous cysts was conducted. Patients were treated using the uniform surgical protocol (cystectomy, preservation of cyst-associated teeth, without use of orthodontic traction, primary wound closure). The metric analysis of the cysts and unerupted teeth on CBCT and an evaluation of the state of involved teeth after the treatment was performed. The mean age of patients was 9.0 ± 2.1 years (range 5-12 years, median = 9 years). All teeth erupted spontaneously. No serious postoperative complications or recurrences of lesions were detected. The mean follow-up was 53.1 ± 15.7 months (range 25-71 months, median = 52 months). The cystectomy of dentigerous cysts with preservation of associated teeth may be considered an alternative to marsupialization in children and preadolescents.

Reduced delay in diagnosis of odontogenic keratocysts with malignant transformation: A case report

BACKGROUND

In rare cases, odontogenic keratocysts (ODs) transform into squamous cell carcinoma. Intervals between the first attendance of a patient and the diagnosis of OD with malignant transformation vary from weeks to years. In this article, we report a case of malignancy derived from OD with a five-day delay in diagnosis.

CASE SUMMARY

A 54-year-old woman was referred to Tongji Hospital in Wuhan, China with complaints of moderate pain, recurrent swelling, and pus discharge around her left maxillary lateral incisor for over 10 years. Physical examination revealed a fistula at the palatine-side mucoperiosteum of the left maxillary lateral incisor and enlarged lymph node in the left neck. Cone beam computed tomography revealed a cystic lesion with massive bone destruction from the left maxillary central incisor to the left secondary maxillary premolar and local bony destruction in the left first mandibular molar. The patient was clinically diagnosed with OD. Enucleation rather than marsupialization was performed given the risk factors of long history, recent aggravated pain, and massive bony destruction. Malignant transformation of OD was confirmed by pathologists 3 d after the operation. Radical surgery was performed, and lymph node metastasis was observed. The patient was subjected to postoperative radiotherapy and synchronous chemotherapy, and no local recurrence or distant metastasis was noted at one-year follow-up.

CONCLUSION

Our case suggests that clinicians should be aware of the malignant transformation of OD, especially when patients present with a long history, massive cyst, chronic inflammation, recent persistent infections, aggravated pain, numbness around the cystic lesion, and lymph node enlargement.

Primary Intraosseous Squamous Cell Carcinoma Arising from a Dentigerous Cyst of the Maxillary Wisdom Tooth

The World Health Organization defines primary intraosseous squamous cell carcinoma (PIOSCC) as a squamous cell carcinoma (SCC) arising primarily within the jaws and having no connection with the oral mucosa. Here, we report a case of PIOSCC in which it was difficult to differentiate the condition from pericoronitis of an impacted maxillary wisdom tooth. The patient was a 27-year-old pregnant woman with a pain in the right maxillary wisdom tooth. The pain was diagnosed as pericoronitis of the right maxillary wisdom tooth, and the tooth was extracted under local anesthesia. During extraction, soft tissue was observed in the coronal part of the tooth, and it was diagnosed as SCC arising in a dentigerous cyst. Because the tumor may still be present, surgical resection was performed under general anesthesia. There has been no recurrence or metastasis at the 1-year follow-up. This case was histopathologically considered from being a benign odontogenic tumor to a malignant tumor. However, it revealed an extensive aberrant type and invasion equivalent to SCC. Thus, the histopathological diagnosis was PIOSCC arising from a dentigerous cyst. Although advanced cases of PIOSCC have been published, diagnosis of PIOSCC in the early stages is rare. In this case, we diagnosed pericoronitis of an impacted maxillary wisdom tooth and extracted the tooth. Therefore, we discovered it accidentally. In the early stages, diagnosis can be difficult both clinically and histopathologically.

Primary Intraosseous Squamous Cell Carcinoma of the Anterior Mandible Arising in an Odontogenic Cyst in 34-Year-Old Male

Primary intraosseous squamous cell carcinoma (PIOSCC) is a rare and aggressive malignancy arising exclusively within the jaws, without any initial connection with the oral mucosa. The etiology and the epidemiology are unclear due to the rarity of the disease, and there is no current universally accepted staging or treatment protocol. Clinically, the posterior mandible is the most affected site, and common symptoms are swelling and pain. The diagnosis is often difficult either because it requires stringent criteria to be satisfied or because of the absence of a pathognomonic histological pattern. Aggressive surgery is the first-choice treatment, often followed by radiotherapy. The lymph nodal status seems to be the most important factor influencing the prognosis, which is usually poor, with a 5-year survival rate ranging from 30% to 40%. In the present article, we report an unusual case of cystogenic PIOSCC interesting the anterior mandible of a young 34-year-old male, which came to our attention after complaint about recurrent infective episodes affecting a dentigerous cyst (impacted lower canine) discovered ten years before. The age, site, and extension are uncommon. Extensive surgical treatment with fibula free flap reconstruction, adjuvant therapy, and salvage surgery was carried out. The patient was disease-free at a 31-month follow-up.

Floating teeth appearance: A radiographic dilemma

Gorham disease (GD) is an extremely rare disorder that is characterised by massive osteolysis of the affected bone with unknown aetiology and an unpredictable prognosis. Additionally, no standard treatment is available for GD. This article describes a case report of a 61-year-old Malay woman who was diagnosed with GD of the anterior mandible without a prior history of trauma. She presented with pain and mobility of the dentoalveolar segment for 3 months. The radiographic findings showed “floating teeth” with widening of the periodontal ligament space and localized area of bony destruction. Histopathologically, there was proliferation of numerous dilated endothelial-lined channels within the intertrabecular tissue. Some areas of bone were replaced by fibrous connective tissue giving rise to the appearance of a benign fibroosseous lesion. The patient was managed with simple removal of the affected bone segment under local anaesthesia, followed by prosthodontic rehabilitation. Healing of the surgical site was uneventful, and no recurrence was reported at the 3-year follow-up.

Delayed diagnosis of a primary intraosseous squamous cell carcinoma: A case report

Primary intraosseous squamous cell carcinoma is a rare malignant central jaw tumor derived from odontogenic epithelial remnants. Predominantly, it affects mandible, although both jaw bones may be involved. This report describes a 60-year-old man who was initially misdiagnosed with a periapical infection related to the right lower wisdom tooth. After four months, the patient presented to a private dental clinic with a massive swelling at the right side of the mandible. Panoramic radiographs and advanced imaging revealed a lesion with complete erosion of the right ramus, which extended to the orbital floor. A biopsy from the mandibular angle revealed large pleomorphic atypical squamous cells, which is the primary microscopic feature of a poorly differentiated squamous cell carcinoma.

Remarkable Short-Term Regression of a Posterior Mediastinum Metastasis From Primary Intraosseous Carcinoma Treated With Nivolumab: A Case Report

Primary intraosseous carcinoma (PIOC; not otherwise specified) is a rare odontogenic malignancy that is believed to arise from the odontogenic epithelium. In addition, some cases arise in odontogenic cysts or other benign precursors. There are no established treatment protocols for PIOC because of its rarity. In particular, no standard therapy has been established for patients with recurrent or metastatic PIOC. This report describes a case in which the use of nivolumab showed a marked treatment response in metastatic PIOC. The patient was a 71-year-old man with PIOC. The patient underwent segmental mandibulectomy with modified radical neck dissection after neoadjuvant chemotherapy, including 2 cycles of paclitaxel, cetuximab, and carboplatin and 1 cycle of docetaxel, cisplatin, and 5-fluorouracil. The lesion rapidly enlarged during neoadjuvant chemotherapy, and surgical specimens showed no histologic therapeutic effects of chemotherapy. Three months after the surgery, contrast-enhanced computed tomograms showed posterior mediastinal lymph node metastasis. Treatment with nivolumab was initiated, and notable clinical improvement was noted after 2 cycles. Although it was a short-term treatment, remarkable effects were observed and no adverse events were noted during and after nivolumab treatment. Nivolumab could be an attractive treatment option for metastatic PIOC that is resistant to traditional chemotherapy and target therapy, including cetuximab. Further investigation of this treatment is warranted.

Data Set for the Reporting of Malignant Odontogenic Tumors: Explanations and Recommendations of the Guidelines From the International Collaboration on Cancer Reporting

A data set has been developed for the reporting of excisional biopsies and resection specimens for malignant odontogenic tumors by members of an expert panel working on behalf of the International Collaboration on Cancer Reporting, an international organization established to unify and standardize reporting of cancers. Odontogenic tumors are rare, which limits evidence-based support for designing a scientifically sound data set for reporting them. Thus, the selection of reportable elements within the data set and considering them as either core or noncore is principally based on evidence from malignancies affecting other organ systems, limited case series, expert opinions, and/or anecdotal reports. Nevertheless, this data set serves as the initial step toward standardized reporting on malignant odontogenic tumors that should evolve over time as more evidence becomes available and functions as a prompt for further research to provide such evidence.

Verrucous carcinoma arising from a previous cystic lesion: a case report

Background

Verrucous carcinoma (VC) accounts for 1–10% of cases of squamous cell carcinoma (SCC) in the oral cavity, and 75% of VC occur in the oral cavity. Only 3% of primary intraosseous squamous cell carcinomas (PIOSCC), which means SCC occurring primarily in the bone, are VC. Verrucous carcinoma arising from odontogenic cysts (OC) is very rare, with only seven cases reported to date.

Case presentation

This study reported a case of a patient who underwent partial maxillectomy and neck dissection for VC that occurred in the right anterior maxilla. The patient was admitted to the emergency department at our institution 8 years ago and showed cystic lesions in the anterior maxilla on facial computed tomography (CT) images. Treatment through other departments including assessment of laceration in the mental region and only suture was performed. This report highlights a very rare case of VC in the right anterior maxilla arising from a previous cystic lesion.

Conclusions

Since PIOSCC can arise from OC, appropriate treatment of intraosseous cysts and regular radiologic evaluation are necesssary. Surgical exicision of the primary lesion without neck dissection can lead to good prognosis for patients with primary intraosseous verrucous carcinoma.

Pediatric case of squamous cell carcinoma arising from a keratocystic odontogenic tumor

Keratocystic odontogenic tumors (KCOT) are exceptional in children and adolescents as they usually occur in the third decade. The present study reports the case of a 15 years old girl who was diagnosed with a KCOT that underwent malignant transformation. KCOT diagnostic was based on clinical, radiological, histopathological and immunohistochemical findings. A conservative treatment by enucleation was performed. Histopathological analysis of the surgical specimen concluded to a KCOT, with an infra-centimetric focus of well-differentiated squamous cell carcinoma. Owing to the well-differentiated character of the squamous cell carcinoma, a single clinical and MRI surveillance every 3 months was decided, without complementary treatment.

Orthokeratinized odontogenic cysts: a Spanish tertiary care centre study based on HPV DNA detection

Background

The role of human papillomavirus (HPV) in orthokeratinized odontogenic cysts (OOCs) has rarely been studied. The objective is to describe the clinicopathological findings in a series of OOCs from a Spanish population that were investigated in relation to the possible presence of HPV.

Methods

A clinicopathological retrospective analysis followed by a molecular analysis of 28 high- and low-risk HPV genotypes was performed in OOC samples of patients seen during the last 15-years in a Spanish tertiary care center.

Results

Of 115 odontogenic cysts with keratinization, 16 cases of OOCs were confirmed and evaluated. OOCs occurred predominantly in the mandible of males (mean age 36.06 ± 13.16 years). Swelling of the jaw followed by pain were the most common clinical symptoms, and 56.5% of the OOC cases were associated with an unerupted tooth. After a mean post-cystectomy follow-up of 3.8 years, only one recurrent case was observed, resulting in a verrucous cystic lesion that was considered premalignant after immunohistological examination. DNA extraction was successful from 14 of the 16 OOC cases. None of the primary OCCs or the single recurrent OOC were positive for HPV in the molecular analysis.

Conclusions

OOCs show a very limited potential for recurrence. Our results suggest that neither high- or low-risk HPV subtypes are likely to play a role in the etiology or neoplastic transformation of OOC, at least in the Spanish population.

Initial-Stage Primary Intraosseous Squamous Cell Carcinoma Derived from Odontogenic Keratocyst with Unusual Keratoameloblastomatous Change of the Maxilla: A Case Report and Literature Discussion

Primary intraosseous squamous cell carcinoma (PIOSCC) is a rare malignant neoplasm derived from odontogenic epithelial remnants in the central jaw bone. Most PIOSCCs originate from odontogenic cysts with a nonkeratinized epithelial lining, especially from radicular/residual and dentigerous cysts. There have been few reports of PIOSCCs derived from the odontogenic keratocyst (OKC), particularly those describing pathological features at the initial stage. The diagnosis of PIOSCC is difficult and based on exclusion of other carcinomas, including metastatic tumors from other primary sites. Here, we report an extremely rare case of initial-stage PIOSCC derived from the OKC with unusual keratoameloblastomatous change of the maxilla.

Solid type primary intraosseous squamous cell carcinoma in a cat

Background

Squamous cell carcinoma (SCC) is the most common nonodontogenic oral tumor in cats. In the jaw, it usually presents as an ulceroproliferative lesion associated with enlargement of the affected bone.

Case presentation

This report describes the case of a cat in which clinical and radiographic findings of a mandibular swelling were suggestive of an aggressive process, but the oral mucosa was unaffected. The results of histopathological and immunohistochemical examination of the samples obtained from the intraosseous lesion were consistent with SCC. The animal was euthanized 5 months after initial presentation as a result of the severe progression of the disease, and no other primary tumors were identified at necropsy.

Conclusions

Based on the clinicopathological, microscopic, and immunohistochemical staining features, as well as the absence of a primary tumor at a distant site, we propose that the term, solid type primary intraosseous SCC (PIOSCC), be used to describe this neoplasia, as it shares similar features with human PIOSCC.

Primary intraosseous squamous cell carcinoma of the mandible: locoregional control and survival is significantly reduced if the tumour is more than 4cm in size

To establish the prognostic factors for primary intraosseous squamous cell carcinoma we designed a retrospective study of patients treated in the head and neck department of a tertiary referral centre in China from 2010-2015. We collected clinical, radiological, and histopathological data from 36 patients treated during the given time period, among which 34 were followed up. There were 22 male and 12 female patients, 13 of whom gave a history of smoking tobacco and four who drank alcohol. All 34 patients were treated by segmental mandibulectomy and neck dissection. Nine had cervical lymph node metastases on histopathological examination, and none had invaded surgical margins. Twenty-eight were treated with radiotherapy postoperatively. During follow up nine died of locoregional recurrence or metastases. Specific factors such as cervical lymph node metastases were related to a greater likelihood of locoregional recurrence. Patients who drank alcohol were also more likely to develop metastases postoperatively. Tumours more than 4cm in size were significantly associated with reductions in locoregional control and survival.

Odontogenic tumors: where are we in 2017 ?

Odontogenic tumors are a heterogeneous group of lesions of diverse clinical behavior and histopathologic types, ranging from hamartomatous lesions to malignancy. Because odontogenic tumors arise from the tissues which make our teeth, they are unique to the jaws, and by extension almost unique to dentistry. Odontogenic tumors, as in normal odontogenesis, are capable of inductive interactions between odontogenic ectomesenchyme and epithelium, and the classification of odontogenic tumors is essentially based on this interaction. The last update of these tumors was published in early 2017. According to this classification, benign odontogenic tumors are classified as follows: Epithelial, mesenchymal (ectomesenchymal), or mixed depending on which component of the tooth germ gives rise to the neoplasm. Malignant odontogenic tumors are quite rare and named similarly according to whether the epithelial or mesenchymal or both components is malignant. The goal of this review is to discuss the updated changes to odontogenic tumors and to review the more common types with clinical and radiological illustrations.

Squamous cell carcinoma arising from a keratocystic odontogenic tumor: a case report

Background

The term “primary intraosseous squamous cell carcinoma” was introduced in 2005 by the World Health Organization with three subcategories. Squamous cell carcinoma arising from the lining of an odontogenic cyst is one important rare subcategory of such lesions with an incidence of 0.01 to 0.02%. Furthermore, the appearance of such malignancy in an odontogenic tumor such as keratocystic odontogenic tumor is considered extremely rare.

Case presentation

In this case report we report a case of a 50-year-old Sri Lankan woman who complained of pain and increase in the size of a swelling at the anterior mandible, which had been present for over 1 year. The increase was significant for 1 month with accompanying numbness of the left half of her lip. Cone beam computed tomography results revealed an irregular radiolucent lesion involving most of her mandible and, except in the anterior part, very little buccolingual expansion was seen that suggested a keratocystic odontogenic tumor. An excision biopsy of the cyst lining confirmed a squamous cell carcinoma arising from a preexisting keratocystic odontogenic tumor.

Conclusions

Even though primary intraosseous squamous cell carcinoma arising from a keratocystic odontogenic tumor is considered to be very rare, the present case is comparable to most of the aspects cited in the literature. The current case emphasizes the importance of careful investigation of swellings present in the mandible. Clinicians as well as patients should be aware and detect these changes to avoid being clinically negligent.

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

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