Some current concepts on the pathology of ameloblastomas

Unicystic ameloblastoma appeared as a massive multilocular entity: A case report with long-term follow-up

INTRODUCTION

Unicystic ameloblastomas are a rare variant of ameloblastomas, which are characterized by slow growth and being relatively locally aggressive, with the main site of origin being the posterior portion of the mandible, it also refers to those cystic lesions that show clinical, radiographic, or gross features of a jaw cyst.

PRESENTATION OF CASE

A 27-year-old female patient presented with a chief complaint of extensive mass of mandible along with severe swelling and numbness of right lips and chin. The oral examination revealed a swelling in the molar region of the right mandible with buccal plate expansion. The radiographic and histopathologic features were consistent with the diagnosis of unicystic ameloblastoma. Consequently, the lesion was surgically removed, and no clinical or radiological recurrence was detected during 5 years post-operative follow-up.

DISCUSSION

While previous reports of unicystic ameloblastoma in the posterior portion of the jaw showed favorable prognosis lesions appeared as a unilocular entity, this case reports multilocular appearance and aggressive behavior of expansive unicystic ameloblastoma. Furthermore, while some studies linked the unilocular appearance of unicystic ameloblastoma to impacted tooth, our case suggests a possible traumatic link of preexisting lesion into multilocular unicystic ameloblastoma related to impacted tooth.

CONCLUSIONS

This case presents a rare multilocular unicystic ameloblastoma appearance, notably with impacted tooth involvement. It also indicates the potential transformation of solid ameloblastoma into unicystic ameloblastom.

Analysis of the 100 most cited articles on ameloblastoma

OBJECTIVES

An increasing number of articles are published each year. The aim of this is to provide a list of the 100 most cited articles on the subject of ameloblastoma.

METHODS

A bibliographic search was performed on Google Scholar (GS), Microsoft Academic (MA), and Dimensions for ameloblastoma. A ranking was created in order of citation density. Graphical representations of keywords and authorship were created with VOSviewer. Statistical analysis was performed and only results with a 95% confidence interval were considered significant.

RESULTS

A helpful list of top 100 articles was developed to help professionals in a variety of ways. Some curiosities are discussed about this scientometric analysis in ameloblastoma articles.

CONCLUSIONS

A useful list of the top 100 most cited articles on ameloblastoma has been provided. Bibliometric and altmetric analysis using Google Scholar, Microsoft Academic, and Dimensions is a free and excellent tool, not only as a citation manager but also as a study reference.

Fibular Free Flap and Iliac Crest Free Flap Mandibular Reconstruction In Patients With Mandibular Ameloblastomas

ABSTRACT

Ameloblastoma (AM) is the most common, locally aggressive odontogenic tumor. It comprises about 1% of all head and neck neoplasms. It occurs mainly in young adults in their 3rd and 4th decade of life. It localizes in the mandible in about 80% of the cases. According to the 2017 WHO classification, 4 types of ameloblastoma can be distinguished: ameloblastoma (previously referred to as solid/multicystic-SMA; the "conventional type" AM), unicystic (AM-UA), extraosseous/peripheral (AM-PA), and malignant/metastatic (AM-MA). Solid, multicystic is the most common type. It is characteristic for its aggressiveness and high risk of recurrence. Radical resection with consecutive reconstruction is the treatment of choice of mandibular ameloblastomas.In this study, the authors present their experience in the surgical treatment of mandibular ameloblastomas with vascularized free flap reconstructions. They discuss new technological possibilities that could improve the precision of the reconstructive procedure and therefore result in the better aesthetic outcome.The retrospective study of a group of 21 patients suffering from mandibular ameloblastoma who underwent segmental mandibulectomy with simultaneous microvascular free flap reconstruction was conducted. A thorough clinical analysis with various aspects was performed. Tumors resected before 2017 were double checked patomorphologically and assigned to the corrected subtype group.Seven patients were admitted to the department due to recurrent ameloblastoma. The most common localization of the tumor was the mandibular body (n = 6) and body with ramus of the mandible (n = 6). A total amount of 10 iliac crest free flaps and 12 fibular free flaps were performed. Complications were reported in 4 patients. A purulent oro-cutaneus fistula occurred in 3patients. There was a flap failure in each reconstructive group. The virtual surgical planning with intraoperative cone-beam computed tomography was used in 3 patients. Dentition implantation was conducted in 4 patients (3 simultaneously, 1 postponed). The mean follow-up was 5 years and 8 months.Radical resection that covers radical segmental mandibulectomy with immediate microvascular free flap reconstruction is a first-line and only effective treatment of mandibular ameloblastomas, that eliminates the risk of recurrence. The extent of surgical margins seems not to influence the recurrence rate, yet further investigation with statistical analysis should be performed. The choice of the adequate free flap must be adapted to dimensions and localization of the tumor and to each patient individually.New technologies such as virtual surgical planning with 3D models and intraoperativecone-beam computed tomography can make the reconstruction more accurate, improving patient's quality of life.

Association of clinicopathological factors and treatment modalities in the recurrence of ameloblastoma: Analysis of 624 cases

BACKGROUND

Ameloblastoma is an odontogenic tumour exhibiting locally invasive behaviour and high recurrence rate after treatment. Conventional ameloblastoma is reportedly been more aggressive showing infiltrative growth patterns and a tendency for recurrence. This is a retrospective study performed to analyse the relationship between clinicopathological characteristics and treatment modalities in the recurrence of ameloblastoma.

METHODS

624 cases of ameloblastoma comprising of 519 non-recurrent ameloblastoma and 105 recurrent ameloblastoma from two main diagnostic centres in Malaysia and Sri Lanka were included. The demographic data, clinical characteristics, histopathological data, treatment modality and episodes of recurrence were extracted and analysed.

RESULTS

The mean age for recurrent ameloblastoma was 37.23 with a peak occurrence in the third decade of life. Recurrent ameloblastoma was marginally female predominant with male to female ratio of 1:1.3. Mandible was the commonest site for the recurrence with a predilection for more than two segments of left mandible followed by left posterior mandible. Follicular (58.1%) histopathological variant was the most reported type to recur followed by plexiform (17.1%). 49.5% of recurrent cases were treated with conservative approach. 65.7% of recurrent cases demonstrated a single episode of recurrence. Mixed (follicular and plexiform) histopathological variants showed the longest average years (11.5 years) for the single episode of recurrence. Plexiform ameloblastoma treated with conservative approach recurred in the shortest follow-up period. The recurrence of ameloblastoma was significantly associated with age group, sub-site of occurrence and histopathological variants (p<0.05).

CONCLUSION

This study showed that age, sub-site of occurrence and histopathological variants are significant factors responsible for the recurrence of ameloblastoma.

Presentation, Diagnostic Imaging, and Clinical Outcome of Conventional Ameloblastoma in Dogs

A noninductive tumor of odontogenic epithelium occurs within the tooth bearing regions of the jaw in dogs and fits the conventional definition of ameloblastoma, which is distinct from, and less common than, canine acanthomatous ameloblastoma. In order to clarify the clinical and radiological features of this uncommon odontogenic tumor in dogs, we performed a retrospective study of 20 dogs that were diagnosed between 2007 and 2015. Follow-up information was obtained for 17 of 20 dogs. The study group of dogs showed no apparent age, breed, or gender predilection. Conventional ameloblastoma is typically slow growing, well demarcated, and locally destructive. Tumors most commonly occurred as a mass or focal bony swelling within the maxilla (13/20) or mandible (7/20). Based on cases with available diagnostic imaging, as either dental radiographs or computed tomographic images, the tumors were usually intraosseous and caused mixed lytic/proliferative bone changes. Nevertheless, conventional ameloblastomas did not aggressively infiltrate adjacent tissues and recurrence was not observed within the study group, even in patients with narrow surgical margins or treatment by cyst enucleation.

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.

Reconstruction of Deep Circumflex Iliac Artery Free Flap for Multiple Recurrent Ameloblastoma in Mandible

Ameloblastoma is the most common odontogenic tumor of epithelial origin. These tumors are benign in nature but have a high rate of recurrence and possible malignant development when treated inadequately. However, recurrent ameloblastomas in bone grafts are rare. This article presents a rare case of a multiple recurrent ameloblastoma, with the last recurrence in a nonvascularized free iliac bone graft of the mandible, reconstructed with vascularized deep circumflex iliac artery free flap for the surgical defect. Furthermore, an updated review of the literature on recurrent ameloblastomas affecting the bone graft is provided.

Peripheral ameloblastoma with neoplastic osseous invasion versus peripheral intraosseous ameloblastoma: A challenging diagnosis

Peripheral ameloblastoma, a soft-tissue analogue of intraosseous ameloblastoma, is a rare odontogenic tumor with histologic characteristics of ameloblastoma. In contrast to conventional ameloblastoma, peripheral ameloblastomas are considered as innocuous lesions which usually do not show invasion of the underlying structures. Rarely, intraosseous ameloblastoma which penetrates the alveolar bone can fuse with the overlying oral epithelium and eventually manifest as an exophytic peripheral lesion. Such lesions which mimic peripheral ameloblastoma both clinically and microscopically are termed as peripheral intraosseous ameloblastoma. As per the existing criteria, soft-tissue ameloblastomas showing bone invasion are strictly excluded from the category of peripheral ameloblastoma and are considered as peripheral intraosseous ameloblastoma. We report a rare case of extraosseous ameloblastoma with clear origin from the superficial epithelium showing the presence of a few odontogenic islands in the underlying bone suggestive of a neoplastic osseous invasion. This paper discusses the diagnostic challenges associated with peripherally occurring ameloblastomas and stresses the need for accurate diagnosis in deciding the treatment modalities.

Conservative surgical treatment for ameloblastoma: a report of three cases

Ameloblastoma treatment varies based on the clinical, histopathologic, and radiographic characteristics. Aggressive surgical treatments, such as marginal or segmental resection, have traditionally been implemented, but some conservative surgical methods are also being introduced, including decompression, enucleation, or curettage. The aim of the present study was to evaluate the possibility of applying these conservative surgical treatments to ameloblastoma and to analyze the prognosis of the procedures and their healing aspects. Among all patients who visited our clinic (Department of Oral and Maxillofacial Surgery, Kyung Hee University Dental Hospital at Gangdong) from 2009 to 2017, three who had undergone conservative surgery were recruited. One of these three patients underwent both excision of the lesion and an iliac bone graft during the same procedure. In the other two patients, due to the size of the lesion, decompression was performed to reduce the size of the lesion, and then conservative surgical treatments followed. As shown in the cases of this study, patients were only treated with conservative surgical methods, such as decompression or enucleation. During the follow-up period, there were no recurrences. In conclusion, the use of conservative surgical treatment in ameloblastoma can be a reliable, safe, and successful method.

Peripheral keratoameloblastoma: A novel case report

Keratoameloblastoma is an exceptionally rare subtype of ameloblastoma that has been reported <20 times previously in the literature. All present as intraosseous lesions. We report an unusual case of keratoameloblastoma localized in the palate without involving palatal bone, thus presenting as a peripheral lesion. To the best knowledge of the authors, no case of peripheral keratoameloblastoma has been reported in the English literature till now, probably rendering this case to be the first one. Therefore, the purpose of this article is to present a rare and the first case of peripheral keratoameloblastoma with histopathological features of this tumor.

Ameloblastoma: A retrospective analysis of 31 cases

Aims and objective

To evaluate the surgical treatment given and do a regular follow up to study the recurrence rate and complications of ameloblastoma in our institution.

Materials and methods

A total of 31 cases of various subtypes of ameloblastoma, treated with different modalities, in the Department of OMFS, were recalled for a follow up & radiographs were taken along with the clinical examination for any recurrence or complications such as fracture/exposure of the reconstruction plate, loosening of the screw, infection of the graft, any draining sinus/signs of infection.

Results

Two of our patients had fractured reconstruction plate, one patient developed infection, one patient complained of screw exposure and two other patients had infection of the iliac graft.

Conclusion

We conclude that an adequate resection with a safe margin could be a treatment option and can be undertaken depending on the extent, location of the lesion and histopathologic variant.

Odontogenic Cysts and Neoplasms

This article reviews a myriad of common and uncommon odontogenic cysts and tumors. The clinical presentation, gross and microscopic features, differential diagnosis, prognosis, and diagnostic pitfalls are addressed for inflammatory cysts (periapical cyst, mandibular infected buccal cyst/paradental cyst), developmental cysts (dentigerous, lateral periodontal, glandular odontogenic, orthokeratinized odontogenic cyst), benign tumors (keratocystic odontogenic tumor, ameloblastoma, adenomatoid odontogenic tumor, calcifying epithelial odontogenic tumor, ameloblastic fibroma and fibroodontoma, odontoma, squamous odontogenic tumor, calcifying cystic odontogenic tumor, primordial odontogenic tumor, central odontogenic fibroma, and odontogenic myxomas), and malignant tumors (clear cell odontogenic carcinoma, ameloblastic carcinoma, ameloblastic fibrosarcoma).

A Conservative Approach to a Peripheral Ameloblastoma

Peripheral Ameloblastoma (PA) is the rarest variant of ameloblastoma. It differs from the other subtypes of ameloblastoma in its localization: it arises in the soft tissues of the oral cavity coating the tooth bearing bones. Generally, it manifests nonaggressive behavior and it can be treated with complete removal by local conservative excision. In this study we report a case of PA of the maxilla in a 78-year-old female patient and we describe the four different histopathological patterns revealed by histological examination. After local excision and diagnosis, we planned a long term follow-up: in one year no recurrence had been reported. The choice of treatment is illustrated in Discussion.

Argument for the conservative management of mandibular ameloblastomas

Ameloblastoma is a rare, benign, odontogenic tumour that affects the mandible more commonly than the maxilla. Solid or multicytic variants are often resected and the defects reconstructed with a free flap. To establish the outcome after enucleation and application of Carnoy's solution, irrespective of histological subtype, we used the hospital's histology database to identify all the patients treated between 2001 and 2014 by one surgeon. Variables included patients' characteristics, histological subtype, radiological appearance, follow-up period, and incidence of recurrence. A total of 27 patients (13 male) were included, mean age 41 years (range 12-79). Fifteen (56%) had solid multicystic lesions, and there was an overall predominance of the follicular or plexiform variant, or both. Of the 23 preoperative radiographs that were available, 17 lesions were unicystic, 5 multilobular and scalloped with no septa, and one had aggressive features of multilocularity and a poorly defined peripheral margin. The mean duration of follow up was 38 months (range 3-156). Three patients had recurrence at 20, 27, and 35 months postoperatively, and each had repeat enucleation and application of Carnoy's solution. Reconstruction was not necessary, and to date none has recurred. This study shows the potential benefits of conservative surgery and sterilisation of the cystic cavity with Carnoy's solution. Recurrence is low, and with vigilant surveillance, similar repeat procedures have been effective when necessary. A longer follow-up period and larger numbers of patients are now needed to corroborate these findings.

A Rare Simultaneous Occurrence of Odontogenic Keratocyst and Unicystic Ameloblastoma in Mandible: A Case Report

Odontogenic Keratocyst (OKC) and Ameloblastomas are slow growing benign odontogenic lesions that primarily occur in the molar region of the mandible. Clinically and radiographically both ameloblastoma, especially the Unicystic ameloblastoma and OKC are indistinguishable due to the similar location of occurrence and the age of patients. It is very rare for these lesions to arise simultaneously in a patient's jaw. The co-occurrence of Ameloblastomas with odontogenic cysts or other odontogenic lesions (histologically in a single lesion)have already been described as combined or hybrid lesions. There are very few reported cases in the English literature for simultaneous occurrence of Unicystic Ameloblastoma and OKC as completely distinct lesions. Here we present such a rare case of the simultaneous occurrence of OKC and ameloblastoma in the posterior region of the mandible of a 22-year-old male in close relation.

Ameloblastomatous Change in Radicular Cyst of The Jaw in a Nigerian Population

OBJECTIVE

To determine the incidence, age, gender, jaw-sites and subtypes of radicular cyst, and to determine the incidence of ameloblastomatous change in radicular cyst in a Nigerian population.

METHOD

A 10-year retrospective analysis of all diagnosed orofacial lesions in the Department of Oral Pathology and Medicine, University of Benin Teaching Hospital, Benin City, Nigeria.

RESULTS

From the 785 diagnosed orofacial lesions within the study period; there were 54 (6.9%) cases of radicular cysts of the jaws. The peak age group was the 3(rd) decade (n=23, 42.6%) with a mean age of 31 ± 1.7 years. There were 29 (53.7%) males and 25 (46.3%) females, giving a ratio of 1.2:1. The mandible was the commonest jaw-site (n=32, 59.3%). There were 12 (22.2%) cases of periapical cyst which were significantly associated with anterior maxillary site (n=8, 14.8%) [p=0.001]. Seven (13.0%) cases of cystic ameloblastoma were diagnosed among the radicular cysts, with a predilection of the lesions for 3(rd) and 4(th) decades of life (n=6, 11.1%), and posterior mandible (n=5, 9.3%).

CONCLUSION

This study showed a low incidence of radicular cyst of the jaw among orofacial lesions and a relatively higher incidence of ameloblastomatous change in radicular cyst compared to previous reports. Immuno-histochemical examination is recommended to differentiate radicular cyst with ameloblastomatous-like change from cystic ameloblastoma arising from radicular cyst.

Clear cell odontogenic carcinoma: report of 7 new cases and systematic review of the current knowledge

OBJECTIVE

The goal of this study is to describe 7 cases of clear cell odontogenic carcinoma among a Brazilian population and compare these data with a systematic review of the English-language literature.

STUDY DESIGN

Descriptive statististics were used to compare the clinicopathologic data gathered retrospectively with those compiled from a review. Tumor sections were immunostained for Ki-67, p16, p53, and cytokeratins (CKs) 7, 8, 14, 18, and 19. Log-rank tests were performed for survival analysis.

RESULTS

Most cases occurred in the posterior mandible (5/7, 71.4%), and recurrence was diagnosed in all treated patients. Metastatic disease occurred in 2 patients (28.6%). Tumors were focally positive for CKs 7, 8, 14, and 18 and diffusely positive for CK19, p53, and p16. The mean number of Ki-67-positive cells was 35.2 cells/high-power field. Our systematic review provided evidence that tumor size (P = .046), histologic pattern (P = .034), regional metastasis (P = .001), distant metastasis (P = .001), and local recurrence (P = .05) were of significant prognostic value.

CONCLUSIONS

This study has contributed to improved characterization of clear cell odontogenic carcinoma, which is an aggressive odontogenic malignant neoplasm diagnosed mainly in the posterior mandible of middle-aged women and typically at an advanced stage. Radical surgical procedures remain the gold standard treatment.

Ameloblastoma: demographic data and treatment outcomes from Melbourne, Australia

BACKGROUND

There is a lack of published data on the demographics and treatment outcomes of ameloblastomas treated in Australia. Our objective was to collect this data and compare the findings to other international studies.

METHODS

A retrospective study of 42 patients with ameloblastoma was conducted at The Royal Melbourne Hospital, Australia. Data on the demographic features, management techniques (ablative and reconstructive), and outcomes were collected and analysed.

RESULTS

The majority of tumours were solid/multicystic (81%) and occurred most commonly in the mandible (80.5%). Unicystic ameloblastomas affected a younger age group, with Type 3 being the most common subtype. Overall, the recurrence rate for solid/multicystic ameloblastomas was 14.7%; however, radical surgery was found to have a significantly lower recurrence rate when compared to conservative management (p=0.015), with a mean of 51 months follow-up. Results indicated that vascularized free-flaps had fewer postoperative complications than non-vascularized bone grafts; however, the differences did not reach statistical significance.

CONCLUSIONS

This is the largest clinicopathological study regarding ameloblastoma management from Australia, and our results support the current literature in recommending radical surgery for the treatment of solid/multicystic and Type 3 unicystic tumours.

Establishing the natural history and growth rate of ameloblastoma with implications for management: systematic review and meta-analysis

Background

Ameloblastoma is the second most common odontogenic tumor, known to be slow-growing, persistent, and locally aggressive. Recent data suggests that ameloblastoma is best treated with wide resection and adequate margins. Following primary excision, bony reconstruction is often necessary for a functional and aesthetically satisfactory outcome, making early diagnosis paramount. Despite earlier diagnosis potentially limiting the extent of resection and reconstruction, an understanding of the growth rate and natural history of ameloblastoma has been notably lacking from the literature.

Method

A systematic review of the literature was conducted by reviewing relevant articles from PubMed and Web of Science databases. Each article’s level of evidence was formally appraised according to the Centre of Evidence Based Medicine (CEBM), with data from each utilized in a meta-analysis of growth rates for ameloblastoma.

Results

Literature regarding the natural history of ameloblastoma is limited since the tumor is immediately acted upon at its initial detection, unless the patient voluntarily refuses a surgical intervention. From the limited data, it is derived that the highest estimated growth rate is associated with solid, multicystic type and the lowest rate with peripheral ameloblastomas. After meta-analysis, the calculated mean specific grow rate is 87.84% per year.

Conclusion

The growth rate of ameloblastoma has been demonstrated, offering prognostic and management information, particularly in cases where a delay in management is envisaged.

Recurrent Ameloblastoma in the Free Fibula Flap: Review of Literature and an Unusual Case Report

Ameloblastoma is the second most common odontogenic tumor of the oral cavity with the primary site being the mandible. The ratio of maxillomandibular involvement however is 5:1 in favor of the mandible. The most common complaint is a painless swelling over the mandibular area. Despite its benign nature, ameloblastoma has a high local recurrence rate, with the most recurrences seen within 5 years after operation. Biopsy and radiological evaluation may be helpful in differentiating the subtypes of ameloblastoma. Differentiation is important because some subtypes are more aggressive than the others. Preoperative planning may be done according to this classification, which can help decrease the recurrence rate. In our case, a 26-year-old female patient with recurrent ameloblastoma which developed on the fibular flap is presented. The free fibular flap and the left parasymphyseal part of the mandible were totally excised. Ameloblastoma was confirmed on pathological examination. We reconstructed the left mandibular site with a reconstruction plate and recurrence was not seen during follow up period.

Origin of ameloblastoma from Basal cells of the oral epithelium- establishing the relation using neuroectodermal markers

BACKGROUND AND OBJECTIVES

Basal cell layer of the oral epithelium has been rightfully regarded as a potential source of odontogenic tumours and cysts, but, without substantial evidence. Also, whether the basal cell layer retains within it, some properties of ectomesenchyme, which was imbibed during the early embryogenesis and hence its neuroectodermal relation, is not known. Here, an attempt is made to establish the hidden neuroectodermal potential of the oral epithelium, especially the basal layer, by observing the expression of known neuroectodermal markers, NSE (Neuron Specific Enolase), Synaptophysin and CD99. The expression of the same markers has also been studied in Ameloblastoma, connecting it with oral epithelium, in turn establishing basal cell layer as a potential source of Ameloblastoma.

MATERIALS AND METHODS

Sections of formalin fixed, paraffin embedded tissue samples of 20 cases of Ameloblastoma and 10 cases of Normal Retromolar mucosa, were stained immunohistochemically with NSE, Synaptophysin, CD99 and also with CK-19 and evaluated for positive expression.

RESULTS

Positive reaction was obtained in all the cases of Ameloblastoma and NRM (Normal Retromolar mucosa) with NSE, all the cases of Ameloblastoma and eight cases of NRM with Synaptophysin and in six cases of Ameloblastoma and NRM with CD99. The staining was diffuse and more marked in case of NSE than Synaptophysin and CD99. CK19 staining done to assure that the tissue antigenicity was maintained was positive in all the samples.

INTERPRETATION AND CONCLUSION

A strong relationship between the neuroectoderm, Ameloblastoma and the basal layer of the oral epithelium is established by the study. It favours the hypothesis that the basal cell layer of oral mucosa may be the sought out culprit in most cases of the Ameloblastomas, especially those occurring in the non-tooth bearing area. This would call for the need to incorporate additional therapy in the form of mucosal striping along with the conventional treatment.

Ameloblastic carcinoma: A clinicopathologic dilemma - Report of two cases with total review of literature from 1984 to 2012

Ameloblastic carcinoma (AC) is a rare primary odontogenic tumor that has histological features of both ameloblastoma and carcinoma. A total number of 92 case reports speak about its rare incidence, affecting mostly the mandible as a locally destructive lesion. The maxilla is affected even more rarely as only 35 cases have been reported until 2012 in scientific literature. The clinical course of AC is generally aggressive, with extensive local bone destruction. The most common clinical features include swelling, pain, trismus, significant bone resorption with tooth mobility, dysphonia and intraoral fistula. We report two cases of AC with aggressive behavior.

Extraosseous ameloblastoma of maxillary gingiva- a case report

Amelobasltoma is a benign neoplasm of the jaw bones that originate from the odontogenic epithelium. They are more common on the mandible than the maxilla. Rarely such tumours arise outside these bones, when they are termed extraosseous or peripheral ameloblastoma. We report a case of extraosseous ameloblastoma in a 30 year old woman, who presented with a painless lesion on the upper gingiva. The lesion was excised completely and the histopathology was suggestive of extraosseous ameloblastoma.

Primary treatment of mandibular ameloblastoma with segmental resection and free fibula reconstruction: achieving satisfactory outcomes with low implant-prosthetic rehabilitation uptake

Ameloblastoma is a locally aggressive and disfiguring oral cavity tumour and surgical management is the mainstay of treatment. The ideal management of ameloblastoma should minimise recurrence, restore function and appearance and present minimal donor site morbidity. Conservative management is associated with minimal downtime but high recurrence rates. By contrast, segmental mandibulectomy with appropriate margins have much lower recurrence rates but presents the challenge of reconstruction. Osseointegrated (OI) implants and permanent dental prosthesis, while ideal, are not always available. We conducted a retrospective review on 30 consecutive patients at our centre with unicystic and multicystic ameloblastoma who were treated with segmental mandibular resection and free fibula flap reconstruction. Only three patients underwent OI implant insertion, with 40% of the patients not receiving any form of dental rehabilitation. We performed a functional and aesthetic outcome survey to determine patient satisfaction with this form of treatment. At an average follow-up of 5 years, there were no recurrences of tumour in our population. Of the 26 patients who responded to the survey, 96% of the patients reported that they were satisfied with their appearance, 88% reported an absolutely normal diet and 93% of the patients reported no problems with donor site function. Overall, we found that low uptake of dental rehabilitation did not adversely affect patient satisfaction and outcomes.

Diagnostic dilemma of unicystic ameloblastoma: novel parameters to differentiate unicystic ameloblastoma from common odontogenic cysts

AIM

Diagnostic criteria that have been specified for unicystic ameloblastomas (UAs) are not always helpful to differentiate these cystic tumors from common odontogenic cysts. The aim of this study therefore was to identify additional histopathological features (other than the features considered for the diagnosis of UA at present) that would be helpful to differentiate UA from odontogenic cysts.

METHODS

One hundred histopathologically confirmed unicystic ameloblastomas and 20 cases each of radicular, inflamed dentigerous and non-inflamed dentigerous cysts were selected. Histopathological features of the UAs that are not used as diagnostic criteria at present were identified.

RESULTS

Hyperplastic arcading epithelial proliferations with stellate-reticulum-like and vacuolated cells were always seen associated with inflammation in odontogenic cysts, while in UA plexiform-like areas were also seen without inflammation (P < 0.001). In addition, a spiky rete pattern was observed in non-inflamed UA while this pattern was observed only in inflamed odontogenic cysts. Furthermore, spiky retes together with subepithelial hyalinization were usually observed in UAs while only subepithelial hyalinization was observed in non-inflamed dentigerous cysts.

CONCLUSIONS

Combinations of histopathological features were identified to differentiate non-inflamed UA from common odontogenic cysts. However, presence of inflammatory changes in UA precludes the use of features identified in the present study for diagnostic purposes.

Ameloblastomas: clinical-histopathological evaluation of 85 cases with emphasis on squamous metaplasia and keratinization aspects

OBJECTIVES

Ameloblastoma is a benign odontogenic neoplasm with an origin reputed to reactivation of odontogenic structures. Histological classification is based on microscopic features and architectural distribution of neoplastic cells. The importance of squamous metaplasia and keratinization has been disputed in ameloblastomas. Clinical and histopathological aspects were evaluated of 85 ameloblastomas, with attention to keratinization and squamous metaplasia features.

STUDY DESIGN

Clinical-demographical information of 85 ameloblastomas were gleaned from the medical records. Microscopic analysis of all cases was carried out with emphasis on keratinization aspects of each tumor.

RESULTS

Most ameloblastomas (54.12%) were diagnosed in males with a mean age of 37 years. Fifty-six patients were Caucasians (65.88%) and the mandible was affected in 68 (89.4%) cases. Most cases analyzed presented areas of squamous metaplasia/keratinization. Recurrence was detected in 16 cases; this was not related to keratinization aspects of the tumor.

CONCLUSIONS

Keratinization is a common feature in ameloblastomas with no impact in tumor behavior.

A review of literature on ameloblastoma in children and adolescents and a rare case report of ameloblastoma in a 3-year-old child

A rare case report of a plexiform unicystic ameloblastoma in a 3-year-old girl stimulated us to conduct a review of literature to understand the correlation of this tumor with various factors such as that of age, sex, histopathological correlation, and its incidence rates pertaining to children and adolescent population. This is a case report of ameloblastoma in a 3-year-old patient, along with a literature review of ameloblastoma in relation to age. A computerized literature search using Medline was conducted for published articles on treatment of ameloblastoma. MeSH phrases used in search were ameloblastoma AND age; ameloblastoma AND children. The search was restricted to published articles from 1970 to 2010, as the histological features were not clearly defined until 1st edition of WHO histological classification of odontogenic tumors of 1971, search parameter was also set to select literatures under English language only. An additional systematic hand search was also conducted simultaneously to identify other published articles, considering similar parameters as used for Medline search. Most of search result yielded literatures in which primary importance were given to treatment patterns and prognosis of intervention, there were not much specific article or meta analysis which reviewed on the affected age range of ameloblastoma exclusively. We reviewed the identified literatures with patients' age, case numbers, incidence, sex, location, and histopathology. The statistical data collected were exported to SPSS 16.0 for windows software which performed a descriptive analysis giving an average mean age of 14.1 years (range from 4 to 20); with maximum mean age being 16.0 and minimum mean age being 10.8 with standard deviation of 1.60. Majority of lesions 91.86% (327 of 356) were found between the age group of 11 and 20 years, only 8.14% (29 of 356) were below the age of 10 years. This rare case report highlights occurrence of plexiform unicystic ameloblastoma in maxilla of a 3-year-old girl, which is very much incongruent with the various review of literature on ameloblastoma in children and adolescents. We have emphasized the significance of patient's age and histopathological pattern of the tumor as it has its influence on the treatment plan. However, there is much of research needed with focus in respect to age, histological pattern, and treatment outcomes.

Hybrid peripheral ameloblastoma of cheek mucosa

An unusual case of large buccal tumour has been described. The lesion was clinically compatible with a squamous cell carcinoma, but it had pathological features of an ameloblastoma arising in the soft tissues. Only few cases of extragingival peripheral ameloblastoma were found in a review of the literature. Possible origins of these tumours are still debatable.

Mandibular resection via mandibular-lip L flap for the treatment of extensive multicystic Ameloblastoma

Ameloblastoma is a benign odontogenic tumor accounting for 1% of all tumors of the maxilla and mandibula. The mandibula is committed in 85% of the cases. The tumor is locally invasive, able to infiltrate bone marrow spaces, without radiographic or macroscopic evidence. High recurrence rates are associated with different surgical techniques, which range from simple tumoral enucleation to extensive resections. The authors report a case of a 26-year old female patient with an 8-year history of progressive, non-tender, swelling of the left mandibular region. The intraoral examination showed that the floor of mouth was raised on the left side by a bulging along the bottom of the left mandibular vestibule as well as the lingual region. Over this area, there were ulcerated areas in the alveolar region of the molars and mucosal fenestration in the alveolar and lingual regions were present. A panoramic radiography revealed a multicystic lesion, resembling the soap-bubble shape endosseous lesion. The computed tomography revealed an expandable multicystic lesion compromising both mandibular cortices. The patient underwent a biopsy, which revealed the diagnosis of a multicystic variant of Ameloblastoma, with plexiform pattern, treated with left mandibular resection and immediate installation of a customized prosthesis. After a year of follow-up, no evidence of the tumor relapse was evidenced.

Papilliferous keratoameloblastoma: an extremely rare case report

Odontogenic tumors develop in the jaw bones from the odontogenic tissue-oral epithelium in tooth germ, enamel organ, dental papilla, reduced enamel epithelium, remnants of Hertwig's root sheath or dental lamina, and so forth. Hence, a bewildering variety of tumors are encountered in the maxilla and mandible. Ameloblastoma is the second most common odontogenic neoplasm after odontomes, and it has numerous clinical and histologic variants. We report a very rare histologic variant: the papilliferous keratoameloblastoma which is the fifth reported case in the English literature.

Graft necrosis occurred after iliac crest reconstruction after mandibular segmental resection of ameloblastoma

Ameloblastoma is an uncommon benign odontogenic neoplasm of the maxillofacial region constituting less than 1% of tumors of the oral cavity. Ameloblastomas have been categorized broadly into 3 biologic variants: cystic (unicystic), solid, and peripheral. Unicystic ameloblastoma is a rare and less aggressive variant of ameloblastoma. The aim of this report is to describe a case of cystic ameloblastoma treated with segmental resection and iliac graft reconstruction. The possible reasons of graft failure seen in our patient at the early stage of the healing were also discussed.

Co-expression of Ki-67 and p53 protein in ameloblastoma and keratocystic odontogenic tumor

OBJECTIVES

The purpose of this study was to evaluate the cell proliferation and p53 protein expression in ameloblastomas (ABs), keratocystic odontogenic tumor (KCOT) and dentigerous cyst (DC).

METHOD

The immunohistochemistry were carried out for Ki-67 and p53 protein expression by using MIB-1 clone and DO-7 clone, respectively, in ABs (n = 23), KCOT (n = 32), DC (n = 30), normal oral mucosa (NOM) (n = 12) and fetal oral mucosa (FOM) (n = 10).

RESULTS

Both the Ki-67 LI Labeling index (LI) and p53 LI was significantly higher in ABs than KCOT, DC, NOM and FOM. The Ki-67 LI and p53 LI was significantly higher in KCOT as compared to DC. Ki-67 LI and p53 LI was observed in descending order in ABs, KOCT, FOM, NOM and DC. There was significant correlation between Ki-67 expression and p53 expression in ABs, KCOT, DC and NOM. The densely stained p53 positive cells were noted higher in ABs than KCOT. The very few densely p53 positive cells were noted in DC, NOM and FOM.

CONCLUSION

The results suggest that the p53 protein expression does not necessarily imply an association with malignant disease and/or p53 gene mutation, but a tendency to be expressed in an increasing quantitative and qualitative manner, as the biologic behavior of odontogenic cyst or tumors becomes more aggressive. p53 over-expression may promote cell proliferation in odontogenic lesions. Thus, it can be stipulated that Ki-67 and p53 protein expression can be used as a prognostic marker in odontogenic lesions.

The onset of a peripheral ameloblastoma

Incipient odontogenic tumors often display intermediate features between two or more lesions leading to diagnosis dilemma. We report the onset of a peripheral ameloblastoma fortuitously found subjacent to a nondysplastic leukoplakia in the region of missing 38 teeth of a 52-year-old man. The aim of this paper is the discussion of the microscopical features observed in the case reported which allowed the establishment of the final diagnosis of an early peripheral ameloblastoma.

Peripheral ameloblastoma: a case report and review of literature

Peripheral ameloblastoma, a rare and unusual variant of odontogenic tumour, comprises about 2–10% of all ameloblastomas. The extraosseous location is the peculiar feature of this type of tumour, which is otherwise similar to the classical ameloblastoma. This paper describes a case of peripheral ameloblastoma in a 67-year-old female affecting the lingual alveolar mucosa of the mandibular 32–34 region which was clinically diagnosed as pyogenic granuloma. This paper becomes important due to availability of all data, makeing it a well-documented case.