Immunohistochemical expression of Cyclooxygenase 2 reflects the proliferative activity in the epithelium of odontogenic lesions

Purpose: Odontogenic cysts and tumors comprise a major component of lesions of the oral and maxillofacial region. The pathogenesis of these lesions involves the interaction between the odontogenic epithelium and the ectomesenchyme. However, the clinical behavior of these biological entities is unpredictable. The aim of this study was to evaluate the role of Cyclooxygenase 2 (COX-2) in the pathogenesis and prognostication of odontogenic lesions.Material and method: : In this study formalin-fixed paraffin-embedded tissue section of Odontogenic Keratocyst (n=10) Dentigerous cyst (n=10), Radicular cyst (n=10) and unicystic ameloblastoma (n=10) were immunohistochemically stained with COX-2 (NCL2-COX-2- 4H12) and with Ki 67 (Ki-67 GM001) using standard staining protocols. The cytoplasmic expression of COX-2 in all the lesions was semi-quantitatively assessed. The pattern of expression of COX-2 among the different odontogenic lesions was statistical analyzed using the ANOVA test and the chi-square test.Results: All the 40 odontogenic lesions that were evaluated expressed COX-2 immunohistochemically. A high number of odontogenic epithelial cells expressed COX-2 in most of the odontogenic keratocyst, radicular cyst and unicystic ameloblastomas. The expression of COX-2 was significantly (p=0.036) higher in Unicystic Ameloblastomas and Radicular cyst compared to that of Odontogenic Keratocyst and the dentigerous cyst.Conclusion: The recognition that expression of COX-2 by odontogenic epithelial cells may indeed shed a new light on the biological mechanisms involved in the development of these benign yet aggressive lesions of the jaws. An insight into the molecular interactions occurring in the odontogenic epithelium will aid in better management of these lesions.

Peripheral Odontogenic Fibroma- Case Series of a Rare Benign Tumor

Peripheral odontogenic fibroma (POdF) is a rare benign odontogenic tumor of ectomesenchymal origin which is composed of fibrous connective tissue containing islands, strands or cords of odontogenic epithelium. The lesion is more common among females, commonly seen between the second to fourth decades of life, mostly affecting the anterior region of mandible. Clinically, it may present similar characteristics with other more common gingival lesions such as pyogenic granuloma, peripheral ossifying fibroma and peripheral giant cell granuloma. So, histopathological examination is required for accurate diagnosis. We present here three rare clinical cases of peripheral odontogenic fibroma and their management by complete excision of the lesion with good postoperative outcomes.

Odontoma cístico ceratinizado e calcificante. Apresentação de dois casos

The authors presents two cases of cystic odontoma with aberrant keratinization (ghost cells) and areas of mineralization of the odontogenic epithelium.

Unicystic Ameloblastoma of Mandible: A Case Report

Ameloblastoma is a neoplasm that originates from odontogenic epithelium. It is the second most common neoplasm of the oral cavity. Unicystic ameloblastomas refer to those cystic lesions that show clinical, radiographic, or gross features of a jaw cyst, but on histologic examination show a typical ameloblastomatous epithelium lining part of the cyst cavity, with or without luminal and/ or mural growth. Even though the lesion is not that aggressive as the solid ameloblastoma, an accurate diagnosis should be made. This lesion needs to be treated more aggressively than any other periapical lesions.

Erupting Compound Odontome - A Case Report

Odontomas are asymptomatic, benign odontogenic tumours comprised of dental tissue. Most of the cases usually get detected on routine radiographic evaluation. Odontoma can be classified according to morphology in two different variants, compound odontoma showing anatomic similarity or miniature version of the tooth and complex odontoma having irregular masses with different type of dental tissues. Early detection of such type of silent lesion is mandatory to rule out certain silent but aggressive pathologies. Here, we present a case of erupting compound odontoma of maxillary area in 15-year-old male patient. Development of tooth is a result of complicated interaction between ectodermal and ecto mesenchymal tissue. Sometimes the remnants of such tissues are left behind in the jaw after development and eruption of tooth, which can become a source of development of odontogenic lesions later on.1 As revealed by World Health Organization (WHO), Odontogenic tumours can be classified in three different categories according to their histopathological form.2 1. Odontogenic tumours which develop from odontogenic epithelium without involvement of odontogenic ectomesenchyme, 2. Odontogenic tumours which develop from odontogenic epithelium with involvement of odontogenic ectomesenchyme, with or without formation of dental hard tissue and 3. Odontogenic tumours which develop from odontogenic ectomesenchyme with or without involvement of odontogenic epithelium.2 For such lesions “Odontoma” word was initially given by Paul Broca in 1866, who revealed the term as tumour occurred by the overgrowth of entire dental tissue. The growth of absolutely differentiated epithelial cells as functional ameloblast and mesenchymal cells as functional odontoblast can give rise to a different developmental anomaly coined as Odontomas.3 According to their behaviour and composition, odontomas can be considered as malformations or hamartomas rather than a true neoplasm. 4,5,6 In 2005, World Health Organization (WHO) classified two variants of odontomas, 1. Compound odontomas, which typically appears as unilocular lesions containing multiple radiopaque, tiny tooth like structures commonly known as denticles; and 2. Complex odontomas, which is comprised of an irregular mass of soft and hard dental tissues.

Massive Ameloblastoma and Reconstruction with Free Fibular Graft

Aims: To report a case of massive ameloblastoma in mandible with wide excision and reconstruction with free vascularized fibular graft and titanium plate. Case Description: A 49- year-old male patient complained right facial mass since 5 years ago. Patient underwent right hemimandibulectomy with general anesthesia and pathologic examination revealed folliculare ameloblastoma. The large defect after resection reconstructed with free fibular graft. Fibula was osteotomised and resembled with mandible shape and reconstructed by plate with intact pedicle. Care was taken to protect the periosteal branch of the peroneal artery before performing an osteotomy. Shaping of the resected fibula was done according to the preoperative template. A titanium miniplate with locking screws was used to secure the osteotomized fibula and the mandible. To secure the airway, we performed tracheostomy. Followup after operation, patient still got a defect facial asymmetry in right mandible. Discussion: Ameloblastoma is histologically benign but locally aggressive tumor originating from odontogenic epithelium. After hemimandibulectomy, reconstruction continued with microvascular free fibular graft and titanium plate. Osteotomies were performed with the pedicle still attached. Conclusions: Free vascularized fibular graft with titanium plate is preferrably reconstruction option for large defect after wide excision of mandibular ameloblastoma.

PERIPHERAL ODONTOGENIC FIBROMA: MIMICKING GINGIVAL SQUAMOUS CELL CARCINOMA: A RARE CASE REPORT AND REVIEW OF LITERATURE

In neoplasms Peripheral Odontogenic Tumors(POT) are one of the rare to occur on gingiva, among them, Peripheral Odontogenic Fibroma (POdF) is the most common. A plethora of lesions sharing similar clinical features, makes the diagnosis difcult. POdF is a benign, slow-growing, smooth, exophytic, painless lesion but it may show diverse clinical presentation as erythematous, lobulated, rapidly growing mass which might be tender on palpation overlapping the features with various inammatory gingival conditions to even a gingival squamous cell carcinoma.This results into diagnostic enigma. Histopathologoical examination plays a vital role in these type of cases. Discussed here is a case of POdF mimicking gingival squamous cell carcinoma. Histopathological investigation showed presence of odontogenic epithelium and dystrophic calcication which are the pathognomonic features of POdF. After surgical removal,POdF is seen to recur but, the exact recurrence rate cannot be estimated due to scarcity of reported cases.

Treatment of a BRAF V600E Positive Ameloblastoma in a Pediatric Patient with MEK Inhibitor Monotherapy

Ameloblastomas are uncommon tumors of the odontogenic epithelium standardly treated with radical resection. Recent studies of the genetic landscape of ameloblastoma have revealed the frequent presence of the BRAF V600E mutation, suggesting a possible role for targeted chemotherapy. We present the case of a primary mandibular ameloblastoma found in a 13-year-old female with confirmed BRAF V600E mutation. Prior to invasive surgical intervention she was treated for 8 weeks with the MEK inhibitor trametinib, but her tumor demonstrated little radiographic, clinical, or histologic response. Previous case reports have shown ameloblastoma in adult patients to be responsive to other agents targeting the MAPK pathway. Our observations in the presented case demonstrate the need for further research into the utility of targeted chemotherapy in ameloblastoma treatment.

Dentigerous cyst arising from a denticle in a primary teeth- a rare case report with brief review of literature

Odontogenic cysts are derived from odontogenic epithelium which may develop before or after the formation of tooth. Most of these are developmental in origin. While dentigerous cysts are common odontogenic cysts that are related to the crown of the impacted tooth and known to arise from reduced enamel epithelium.

Adenomatoid Odontogenic Tumour - The Master of Disguise

Adenomatoid odontogenic tumour, truly coined as one of the masters of disguise of orofacial pathologies, was first reported in the literature by Steen Lands.1 Philipson and Brin used the terminology adenomatoid odontogenic tumour for this pathology with its commonly accepted abbreviation AOT.2 Later on, adenomatoid odontogenic tumour (AOT) name was accepted by the World Health Organization (WHO) in 1971. In 2005, WHO revealed the histological variants of the adenomatoid odontogenic tumour and classified it as a tumour comprised of odontogenic epithelium showing various patterns in histopathologic view within a mature connective tissue stroma.3 It is seldom noticed neoplasm which comprises only 3 % of all the odontogenic tumours. It was commonly found in the maxilla with female predilection and mostly in association with impacted canines.4-6 Adenomatoid odontogenic tumour is an odontogenic epithelial tumour usually seen in females in their second decade of life. The tumour is slow growing in nature which eventually results in painless expansion of jaw. The maxilla is commonly affected than mandible. Being benign in nature, most of the AOT cases usually got treated with conservative surgical enucleation but the greater size of tumour can leave behind an oro-facial defect. To prevent such type of incident, it is important to diagnose them early and treat accordingly. Herewith, we are presenting a case report of adenomatoid odontogenic tumour of mandible in a male patient.