Central Granular Cell Odontogenic Tumor: A Literature Review of Cases Reported in the Last 71 Years with a New Case Report

Central granular cell odontogenic tumors(CGCOTs)are rare,benign,slowly growing odontogenic neoplasms.Due to their uncertain histogenesis,CGCOTs are still not included as a distinct entity in the WHO classification(2017)of odontogenic tumors.We report a case of CGCOT involving the right side of maxillary anterior region of a 39-year-old white female.Immunohistochemical staining showed that granular cells positively expressed CD68 and vimentin,and negatively expressed S-100 protein.Meanwhile,we searched Pub Med,Google Scholar,and Scopus databases to summary the clinico-pathological features of 51 reported cases of CGCOT.The results showed that the granular cells of 28.6%cases were immunopositive for vimentin and CD68,and odontogenic epithelial cells were positive immunoreactivity for cytokeratin.These findings reinforced the mesenchymal origin of granular cells and the odontogenic nature of epithelium islands.

Identification of the involvement of LOXL4 in generation of keratocystic odontogenic tumors by RNA-Seq analysis

Keratocystic odontogenic tumors （KCOT） are benign, locally aggressive intraosseous tumors of odontogenic origin. KCOT have a higher stromal microvessel density （MVD） than dentigerous cysts （DC） and normal oral mucosa. To identify genes in the stroma of KCOT involved in tumor development and progression, RNA sequencing （RNA-Seq） was performed using samples from KCOT and primary stromal fibroblasts isolated from gingival tissues. Seven candidate genes that possess a function potentially related to KCOT progression were selected and their expression levels were confirmed by quantitative PCR, immunohistochemistry and enzyme-linked immunosorbent assay. Expression of lysyl oxidase-like 4 （LOXL4）, the only candidate gene that encodes a secreted protein, was enhanced at both the mRNA and protein levels in KCOT stromal tissues and primary KCOT stromal fibroblasts compared to control tissues and primary fibroblasts （P〈0.05）. In vitro, high expression of LOXL4 could enhance proliferation and migration of the human umbilical vein endothelial cells （HUVECs）. There was a significant, positive correlation between LOXL4 protein expression and MVD in stroma of KCOT and control tissues （r=0.882）. These data suggest that abnormal expression of LOXL4 of KCOT may enhance angiogenesis in KCOT, which may help to promote the locally aggressive biological behavior of KCOT.

Clear-cell variant of calcifying epithelial odontogenic tumor (Pindborg tumor) in the mandible

We present an uncommon case （female patient aged 59 years） of the clear-cell variant of calcifying epithelial odontogenic tumor （CEOT） （also known as Pindborg tumor） in the mandible. The clinical characteristics and probable origins of the clear tumor cells of previously reported cases of clear-cell variant of intraosseous CEOT are also summarized and discussed.

Identification of Known and Novel PTCH Mutations in Both Syndromic and Non-syndromic Keratocystic Odontogenic Tumors

Aim To clarify the role of PTCH in patients with NBCCS- related and non-sydromic keratocystic odontogenic tumors. Methodology Mutation analysis was undertaken in 8 sporadic and 4 NBCCS-associated KCOTs. Results Four novel and two known mutations were identifled in 2 sporadic and 3 syndromic cases, two of which being germline mutations （c.2179delT, c.2824delC） and 4 somatic mutations （c.3162dupG, c.1362-1374dup, c.1012 C〉T, c.403C〉T）. Conclusion Our findings suggest that defects of PTCH are associated with the pathogenesis of syndromic as well as a subset of non-syndromic KCOTs.

Mixed odontogenic tumors:A review of the clinicopathological and molecular features and changes in the WHO classification

BACKGROUND Ameloblastic fibromas and ameloblastic fibrosarcomas are rare odontogenic tumors,and controversy exists in the classification of cases presenting hard-tissue production:Ameloblastic fibrodentinoma(AFD)and ameloblastic fibro-odontoma(AFO).These cases are currently considered“developing odontomas”(hamartomatous lesions).AIM To analyze the clinicopathologic features of these lesions and discuss the changes in the 2017 World Health Organization classification.METHODS An electronic literature search was performed in the PubMed/MEDLINE database.An electronic search of the English language literature was performed and last updated in September 2020 in the PubMed/MEDLINE database using the following terms:“ameloblastic fibroma”,“ameloblastic fibrodentinoma”,“ameloblastic fibro-odontoma”,“ameloblastic sarcoma”,“ameloblastic fibrosarcoma”,“ameloblastic fibrodentinosarcoma”,“ameloblastic fibroodontosarcoma”and“odontogenic carcinosarcoma”.The inclusion criteria were odontogenic tumor series,case reports and systematic reviews that provided sufficient clinical,radiological and microscopic documentation to confirm the diagnosis.RESULTS The database search strategy resulted in 947 papers.Articles focusing on other topics,articles that were not in English,duplicate articles,and articles without fulfilling the inclusion criteria were excluded.Finally,96 publications were included in this review to describe and discuss the main features of the searched entities.Several aspects of AFO and AFD,such as biological behavior,age of occurrence,amount of hard tissue,and potential for malignant transformation into odontogenic sarcomas,support the neoplastic nature in most of the reported cases.Considering the clinical,radiographic,histopathological and molecular characteristics of odontogenic lesions with hard tissue production,we suggest that these types of lesions should continue to be recognized as odontogenic tumors by maintaining the classically used terms.CONCLUSION This recommendation will be relevant for future clinical,microscopic,and molecular studies to better understand the biology of these interesting odontogenic tumors.

THE EOSINOPHILIC MATERIAL IN ADENOMATOID ODONTOGENICTUMOR ASSOCIATED WITH AMYLOID PROTEIN COMPONENT

Objective: To investigate the relation between eosinophilic materials and amyloid P (AP) component in adenomatoid odontogenic tumor (AOT). Methods: The expression of amyloid proteins and basement membrane proteins, including type IV collagen, laminin and heparin sulfate proteoglycan (HSPG), in AOT were analyzed by immunohistochemical method. Results: Most eosinophilic droplets among tumor cells and some epithelial cells showed positive stain for AP component. The immunoreactions of type IV collagen and laminin were only found in blood vessels of this tumor. The tumor cells and eosinophilic materials in duct-like structures were constantly unstained for both amyloid and basement membrane proteins. Present results suggest that the nature and composition of eosinophilic droplets may differ from the eosinophilic layer in ductlike structures. This study first demonstrated that the amyloid-like deposition in AOT is associated with AP component by immunohistochemical method. It supported that AP component may be epithelial origin since the AP immunolocalization was found in tumor cells.

Odontogenic Keratocyst Tumor: A Case Report and Literature Review

First described by Philipsen in 1956, the odontogenic keratocyst is characterized by a large squamous keratinization of its border, an aggressive growth and a high recurrent rate. It is now designated by the World Health Organization as a keratocystic odontogenic tumour (KOT). Clinically, the KOT is manifested by an asymptomatic growth. Radiographically, it appears as a well-defined uni-locular or multilocular osteolytic lesion. The diagnostic approach is based on a combined analysis of the medical history, the clinical appearance and the radiographic appearance. The diagnosis may be confirmed by the anatomical pathology report. Finally, treatment consists of surgical excision and follow up is characterized by a high rate of recurrence. The authors report a case of keratocystic odontogenic tumor of the upper jaw and review the various diagnoses, therapeutics and follow up aspects of this type of tumors.

Sclerosing odontogenic carcinoma of maxilla:A case report

BACKGROUND Sclerosing odontogenic carcinoma is a rare primary intraosseous neoplasm that was featured recently as a single entity in the World Health Organization classification of Head and Neck Tumors 2017,with only 14 cases published to date.The biological characteristics of sclerosing odontogenic carcinoma remain indistinct because of its rarity;however,it appears to be locally aggressive,with no regional or distant metastasis reported to date.CASE SUMMARY We reported a case of sclerosing odontogenic carcinoma of the maxilla in a 62-year-old woman,who presented with an indolent right palatal swelling,which progressively increased in size over 7 years.Right subtotal maxillectomy with surgical margins of approximately 1.5 cm was performed.The patient remained disease free for 4 years following the ablation surgery.Diagnostic workups,treatment,and therapeutic outcomes were discussed.CONCLUSION More cases are needed to further characterize this entity,understand its biological behavior,and justify the treatment protocols.Resection with wide margins of approximately 1.0 to 1.5 cm is proposed,while neck dissection,post-operative radiotherapy,or chemotherapy are deemed unnecessary.

Adenomatoid odontogenic tumour displacing multiple teeth in an adolescent

Adenomatoid odontogenic tumor is an unusual benign neoplasm which shares clinical and radiographic characteristics with odontogenic cystic lesions denoting a distinct behavior. This paper reports a case of a 12-year-old boy with a bony consistence tumefaction involving the area from teeth 12 to 17. Radiographically, the lesion was characterized by a well-circum- scribed unilocular radiolucent area displacing maxillary canine, first and second premolars. The final diagnosis was adenomatoid odontogenic tumour. The lesion was enucleated concomitantly with the removal of the canine tooth under general anesthesia. The patient was submitted to orthodontic treatment and has been followed-up for four years. Clinical and radiographic features are discussed in this report.

Calcifying Odontogenic Cyst of the Oral Cavity: A Clinical Case and Current Updates on the Ethiopathogenesis

Background: The calcifying odontogenic cyst (COC) is a rare pathological entity. It falls into a group of lesions with calcifications that present benign and sometime malignant tumor variants. Case Presentation: In the present study, we report on a case of intraosseous/intrasinusal COC with impacted maxillary canine and dentinoid structures odontoma-like. The clinical, radiographical, histopathological, and molecular characteristics of this pathological entity are discussed in relation also to the problems of differential diagnosis, treatment, and prognosis. Conclusion: The true COC is a rare entity in the oral cavity and represents about less than 1% of all odontogenic lesions. Careful clinical, instrumental and histological analysis must be performed for odontogenic cysts in order to accomplish the correct surgical act and to avoid recurrence.

Mandibular cementoblastoma:Case report

Cementoblastoma is a rare benign lesion that represents less than 1% of all odontogenic tumours. It’s characterized by proliferation of cementum-like tissue and in almost all cases tends to be associated with an erupted permanent tooth, most often the first mo- lar. We present an unusual case of a large cemento-blastoma that affected the right mandibular body, extending from the first premolar to the second molar, of a 19-years-old male. In this case an initial surgery was attempted under local anaesthesia, resulting in incomplete tumor removal. A second surgical procedure was performed under general anaesthesia, ensuring the complete excision of the lesion. The patient was monitored for 1 year after surgery and did not show any signs of recurrence.