Odontogenic carcinoma: a functional genomic comparison with oral mucosal squamous cell carcinoma

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 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.

A review of the molecular profile of benign and malignant odontogenic lesions

Odontogenic cysts and tumors are heterogeneous lesions, originating from elements or remnants of the odontogenic apparatus. Although the majority of these lesions are benign and never undergo malignant transformation, rare malignant tumors may arise de novo or from benign precursors. The molecular basis of these lesions is still poorly understood. This article summarizes and discusses studies using small, medium, and large-scale and/or "-omic" techniques to describe the molecular characteristics of benign and malignant odontogenic lesions and briefly debates strategies to increase the use of "-omic" and multi-omic approaches or integrative analyses in the research of these lesions. A comprehensive understanding of the molecular aspects of odontogenic lesions by using large-scale approaches will enable us to refine the classification of this heterogeneous group of disorders and provide more accurate biomarkers for precise diagnosis, prognosis, and development of molecular tools in the management of patients with these conditions.

The dilemma of extensive unilocular radiolucent lesions of the jaws - value of immunohistochemistry as a diagnostic marker and prognostic Indicator

INTRODUCTION

Large Unilocular radiolucent lesions of the jaws often present a dilemma to both, the Oral Pathologist and the Maxillofacial surgeon with regards to their accurate diagnosis as well as their most appropriate treatment modality. A precise identification as to whether the lesion is a cyst or a tumor is imperative before any treatment is instituted. Once the correct diagnosis and likely prognosis are established, a management protocol can be planned which will completely eliminate the lesion, while at the same time, ensure least possible morbidity for the patient, such as pathological jaw fractures, persisting neurological deficits, esthetic deformity, functional debility, recurrence/persistence of the lesion, etc. AIM & OBJECTIVES: To establish the value of Immunohistochemistry (IH) as a Diagnostic marker and Prognostic indicator for extensive Unilocular radiolucent lesions of the jaws. To assess its role as an adjunct to Histopathological Examination (HPE) in distinguishing Odontogenic tumours from the cysts, by identifying the former using IH Tumor Markers; and in aiding in selection of the most appropriate and effective treatment option for each of such ambiguous lesions, based on their prognosis as indicated by the expression of lH Cell Proliferation Markers.

MATERIALS AND METHOD

Thirty cases of large Unilocular Radiolucent lesions of the jaws (Maxilla/Mandible) were managed over a period of three years. Histopathological examination (HPE) and Immunohistochemical (IH) analysis were carried out of the biopsy specimens in all the cases. Calretinin, an Immunohistochemical Tumor marker, was used to distinguish between Odontogenic cysts and tumours. Ki-67 and Proliferating Cell Nuclear Antigen (PCNA), Immunohistochemical Cell Proliferation markers, provided information on the aggressive potential of the lesions. On the basis of the above information, an appropriate management protocol was established for each of these different lesions. Nerve sparing enucleation and curettage was employed for the established cases of Odontogenic Cysts; Enucleation and curettage, peripheral ostectomy, followed by chemical cauterization was employed for the Unicystic Ameloblastomas and other Odontogenic tumours with a low Ki-67 and PCNA Proliferation Index (PI)/Labelling index (LI ≤ 3); Marginal resection was carried out for the tumours with a higher Labelling Index (LI >3 ≤5), and Segmental resection (including partial/complete Maxillectomy, Hemimandibulectomy with/without disarticulation) for the aggressive pathologies with high Labelling Index (LI > 5).

RESULTS

Of the thirty cases of large Unilocular radiolucent lesions of the Maxilla and Mandible, thirteen were diagnosed as Dentigerous cysts, one as Dentigerous cyst showing Ameloblastomatous transformation; two as Unicystic Ameloblastomas, one as the Mural variant of Unicystic Ameloblastoma; four as Follicular Ameloblastomas, two as Plexiform Ameloblastomas; four as Acanthomatous Ameloblastomas; one as Ameloblastic Fibroma and two as Adenomatoid Odontogenic Tumours. The predictive and prognostic indication of the Immunohistochemical markers correlated well with the post treatment findings.

CONCLUSION

In cases of extensive Unilocular lesions of the jaws, where ambiguity often exists in both diagnosis and appropriate treatment plan to be employed, Immunohistochemistry can serve as an invaluable tool in establishing the precise diagnosis, guiding the treatment plan, as well as indicating the likely prognosis of these lesions.

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.

Primary intraosseous squamous cell carcinoma of the maxilla possibly arising from an infected residual cyst: A case report

Primary intraosseous squamous cell carcinoma (PIOSCC) is a rare type of odontogenic carcinoma arising from the jawbone. Odontogenic cysts are true cysts that arise from the dental epithelium, which is associated with tooth formation. The epithelial lining of odontogenic cysts has the potential to transform into various types of odontogenic tumor; however, this transformation from an odontogenic cyst to a malignant tumor is rare. The definitive diagnosis for PIOSCC generally requires the observation of either features of squamous cell carcinoma (SCC) within the jawbone that are distinct from direct invasion from the surface oral epithelium, or evidence of SCC arising from odontogenic epithelium and from tumors that have metastasized to the jawbone from distant sites. In the present study, a case of PIOSCC of the maxilla is presented, which, based on the results of computed tomography and the clinical course, was hypothesized to have originated from an infected residual cyst.

Pathogenesis and nomenclature of odontogenic carcinomas: revisited

Odontogenic carcinoma is rare group of malignant epithelial odontogenic neoplasms with characteristic clinical behavior and histological features, which requires an aggressive surgical approach. The pathogenesis of this rare group remains still controversial and there have been many varied opinions over the classification of this rare group of lesions. As there have not been many reviews on odontogenic carcinoma, the existing knowledge is mostly derived from the published case reports. This review is discussing the pathogenetic mechanisms and is updating the knowledge on nomenclature system of less explored odontogenic carcinomas. This review might throw light on the pathogenesis and nomenclature system of odontogenic carcinoma and this knowledge may be applied therapeutically.

Malignant transformation of keratocystic odontogenic tumor: two case reports

INTRODUCTION

Keratocystic odontogenic tumors (KCOTs) are cystic tumours originating from the dental lamina of the maxilla and mandible that are lined with keratinized epithelium. While benign, they can be locally destructive and have a high recurrence rate despite treatment. Rarely, KCOTs may undergo malignant transformation into Primary Intraosseous Squamous Cell Carcinoma (PIOSCC).

CASE REPORT

This study reports the clinical findings, radiological scans and histopathology of 2 patients with KCOTs that underwent malignant transformation into PIOSCC.

DISCUSSION

A comprehensive literature review was performed to similar reports documenting the malignant transformation of KCOTs. The potential for KCOTs to undergo malignant change should prompt oral maxillofacial surgeons and otolaryngologists to exercise a high index of suspicion when treating these lesions. Patients persisting with unresolved disease after treatment should be investigated for malignant transformation. Detailed histopathological examination of KCOT specimens is recommended to detect small foci of SCC which may be present in the epithelium.

Intraosseous verrucous carcinoma arising from an infected dentigerous cyst-A case report

Intraosseous verrucous carcinoma (IOVC) arising from an odontogenic cyst is extremely rare. We report a case of intraosseous verrucous carcinoma in a 74-year-old male who presented with a left mandibular swelling with recurrent pus discharge from gingiva of tooth #35. Panoramic radiography revealed an impacted tooth #34 and a large well-defined, radiolucent lesion surrounding the crown of tooth #34. The clinical diagnosis was an infected dentigerous cyst. Surgical excision of the cyst together with extraction of tooth #34 was performed. Histopathological examination showed proliferation of hyperparakeratotic stratified squamous cyst lining epithelium and down-growth of broad and bulbous epithelial ridges with pushing border invasion into the fibrous cystic wall. A verrucous carcinoma arising from an infected dentigerous cyst was diagnosed. There was no recurrence of the tumor 5 months after surgery.

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

PURPOSE

To review the literature on primary intraosseous squamous cell carcinoma (PIOSCC) associated with odontogenic cyst.

METHODS

All well-documented cases of PIOSCC published between 1938 and 2010 were collected. Only cases of PIOSCC arising from the lining of an odontogenic cyst, including the keratocystic odontogenic tumor, were selected. Age, sex, signs and symptoms, affected jaw, cyst type, treatment, histopathology, and outcome were recorded.

RESULTS

The mean age was 60.2 years (range 1.3-90). There were 80 (69%) men and 36 (31%) women. Mass and pain were the most common presenting symptoms. The mandible was affected in 92 (79%) patients and the maxilla in 24 (21%). It was a residual/radicular cyst in 70 (60%) patients and a dentigerous cyst or a keratocystic odontogenic tumor in the remaining 40%. The histopathology was well-differentiated SCC in 53 (46%) patients and moderately differentiated SCC in 47 (40%) patients. Fifty-three (46%) patients were treated with surgery alone and 44 (38%) with surgery and radiotherapy. Fifty-eight (62%) patients survived 2 years and 36 (38%) survived 5 years.

CONCLUSION

PIOSCC has a predilection for men (M/F ratio of 2.22:1), affects mainly adults in their 6-8th decades, occurs most frequently (79%) in the mandible, and is associated mainly with a residual/radicular cyst. Histologically, the well-to-moderately differentiated SCC was the most common. Surgery alone or combined therapy of surgery and radiation was the most common approach. The prognosis is 62% surviving 2 years and 38% 5 years.

Epithelial expression of SHH signaling pathway in odontogenic tumors

Sonic hedgehog (SHH) signaling pathway plays a critical role in tooth development. Recent studies indicate that SHH signaling pathway activation occurs both in the odontogenic cyst and ameloblastoma. However, the association of SHH pathway with other subtypes of odontogenic tumor is not well documented. The objective of this paper is to investigate the protein distribution of SHH and its receptor PTC, SMO and transcription factor GLI1 in various odontogenic tumors. Odontogenic tumor tissues including 34 epithelial derived, 24 epithelial-mesenchymal derived, and 26 mesenchymal derived were examined by immunohistochemistry for SHH, PTC, SMO and GLI1. Immunoreactivity for SHH, PTC, SMO and GLI1 was detected in both epithelial derived odontogenic tumors and epithelial-mesenchymal derived odontogenic tumors with or without dental hard tissue formation. Mesenchymal derived odontogenic tumors showed no positive staining except for the focal epithelial cells in island or cord forms within the central portion of the tumor. The protein expression of SHH signaling pathway in malignant odontogenic tumors was no stronger than that in benign tumors. Each of the genes in the pathway was expressed in similar patterns in the same tumor subtype. SHH, PTC, SMO and GLI1 were detected more in the cytoplasm of the epithelial cells than in stromal cells. Immunoreactivity for GLI1 was also detected in the base membrane of the tumor cells. The findings suggest SHH, PTC, SMO and GLI1 protein are predominantly located in epithelial components in various odontogenic tumors and might participate in the proliferation of epithelial components of odontogenic tumors.

Analysis of ameloblastomas by comparative genomic hybridization and fluorescence in situ hybridization

In order to characterize the chromosomal alterations in ameloblastomas, a combination of comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH) techniques was performed on 9 tumors. Chromosomal alterations including a gain at 1q and losses at 1pter, 10q, and 22q could be detected by CGH only in 1 tumor. Interphase FISH analysis, using centromeric probes for chromosomes 1, 10, and 22 as well as region-specific probes for 1p36 and 10q26, revealed the most frequent alterations to exist in the tumor with the abnormal CGH profile. These alterations included marked to slight increases of monosomic cells for chromosome 10 (91.5%), 10q26 (35.8%), 1p36 (24.4%), and chromosome 22 (18.8%), as well as significant elevations of trisomic cells for chromosome 1 (41.2%). Moreover, FISH analysis revealed a frequent loss of chromosome 22 in all tumors examined, except for one lesion, indicating that loss of the entire or a part of this chromosome is a common event in ameloblastomas, possibly being a predisposing factor to ameloblastoma tumorigenesis.

Zirconium oxide: analysis of MG63 osteoblast-like cell response by means of a microarray technology

Zirconium oxide ceramics have outstanding mechanical properties, a high biocompatibility and a high resistance to scratching. Expression profiling by DNA microarray is a molecular technology that allows the analysis of gene expression in a cell system. By using DNA microarrays containing 19,200 genes, we identified in osteoblast-like cells line (MG-63) cultured on zirconium oxide discs (Cercon, Degussa Dental, Hanau, Germany) several genes whose expression was significantly up or down-regulated. The differentially expressed genes cover a broad range of functional activities: (a) immunity, (b) vesicular transport and (c) cell cycle regulation. It was also possible to detect some genes whose function is unknown. The data reported are, to our knowledge, the first genetic portrait of a zirconium oxide surface. They can be relevant to better understand the molecular mechanism of biocompatibility and as a model for comparing other materials.