ASSESSMENT OF DEMOGRAPHICS AND CLINICOPATHOLOGICAL CHARACTERISTICS OF AMELOBLASTOMA – AN OBSERVATIONAL STUDY
6. Brief resume of intendedwork:
Odontogenic tumours are lesions from epithelial and/or ectomesenchymal components of developing teeth or associated structures. These tumors represent only 1% of all jaw tumors 1.
Ameloblastomaisconsidered the most unexplainable of odontogenic tumours, because of its invasive and destructive clinical features and benign histological features.2
Churchill (1937) described ameloblastoma as a tumour that is unicentric, non-functional, intermittent in growth, anatomically benign and clinically persistent3.
This odontogenictumor originates in the jaws from epithelium that is involved in the formation of teeth. Potential epithelial sources include the enamel organ, odontogenic rests (rests of Malassez,rests of Serres), reducedenamelepithelium and the epithelial lining of odontogenic cysts. The trigger or stimulus for neoplastic transformation of these epithelial residues is totally unknown5.
Their occurrence is evenly distributed between the sexes3.
They are slow-growing, locally invasive tumours that run a benign course in most cases4..
Radiographically,it present as multilocular and unilocular lesions surrounded by a radiopaque border,located primarily in the posterior mandibular segment.1
Ameloblastoma occurs in three different clinico-radiographic situations, which deserve separate consideration because of differing therapeutic considerations and prognosis4.
Conventional solid or multicystic (about 86% of all cases)
Unicystic (about 13% of all cases), and
Peripheral or extraosseous (about 1% of all cases)
Histologically, ameloblastoma occurs in several patterns, of which the follicular and plexiform are the main variants5. The follicular type can be further subdivided into a acanthomatous type, a granular type and a basal cell type. The plexiform type contains basal cells arranged in anastomosing strands with an inconspicuous stellate reticulum. The stroma is usually delicate, often with cystlike degeneration.
The unicystic ameloblastoma represents an ameloblastoma variant that on gross examination and not based on the appearance on the radiogragh, present as a cyst. Two histopathological variants are recognized, being the luminal variant and the mural variant.
The extraosseous type shows the histopathological cell type and patterns as seen in the solid/multicystictype.Inthe desmoplastic type the stromal component dominates, compressing the odontogenic epithelial components.6 Common to all subtypes is the palisading of columnar cells around epithelial nests in a pattern similar to that of ameloblasts of the enamel organ.Central to these are loosely arranged cells that mimic the stellate reticulum of the enamel organ10..
6.2 Need for the study:
This study is undertaken to analyze demographic data and clinicopathological characteristics of ameloblastoma at V S Dental College and Hospital over a period of 20years.
6.3Review of literature:
There have been studies conducted on Clinico Pathological analysis of Ameloblastoma.
The study analyzed in 70 ameloblastoma cases from the archives of the Dental School Federal University of Brazil showed 35(50%) occurrence in males and 35(50%) females. Young adults were most affected by tumors. Fifty-six(80%) of the cases occurred in jaw. The main histological subtype seen was unicystic ameloblastoma1.
The study was conducted by government teaching hospital in the southern Indian state of TamilNadu over a period of 38 years(1970-2008).A total of 489 cases of odontogenic tumors in which ameloblastoma formed the single most common tumor with 42.33% solid ameloblastoma,23.93% unicystic ameloblastoma and 1.43% peripheralameloblastoma.The most commonly affected anatomic location was posterior mandible.The patients were affected over an age range of 5-75years with amean age of 32.64years.7
The study evaluated 77 histologically diagnosed cases of ameloblastoma and found that the follicular ameloblastoma was the most common histological type (50 cases, 64.9%) followed by plexiformameloblastoma (10 cases, 13.0%). 4(5.2%) cases of desmoplstic and 3(3.9%) cases of acanthomatous ameloblastoma were seen while the basal cell variant accounted for 2 (2.6%) cases. Only 1 case of the unicystic type was seen 8.
The study reviewed all the cases of ameloblastoma seen at the Oral and Maxillo-Facial Surgery clinic, Nigeria, between 1980 and 2003 showed 207 cases of ameloblastoma and noted 198 (95.7%)were benign, and 9(4.3%) were malignant. A male-to-female ratio 1.1:1 was found. The average ages on presentation for ameloblastoma and ameloblastic carcinoma were 31.67 and 46.44 years, respectively.The lesion was found to be more common in the premolar –molar region of the mandible.The most common histological type was follicular ameloblastoma.[25.1%]9
6.4 Objectives of the study:
1.To describe demographic data of ameloblastoma.
2.To analyze clinical and pathological characteristics of ameloblastoma.
3.To assess variations in demographic data and clinicopathological observations.
7.Materials and methods:
7.1 Source of data:
Histopathologicallydiagnosed cases of ameloblastoma will be included from the archives of the Department of Oral Pathology V. S. Dental College and Hospital, Bangalore over a period of 20 years.[1996-2015]
7.2 Method of collection of data:
7.2.2. Study material:
Formalin fixed paraffin embedded blocks of histopathologicallydiagnosed cases of ameloblastoma.
7.2.3. Study Method:
1.Demographic data like age,gender, location, clinical and pathological findings will be recorded.
2.The selected paraffin embedded blocks will be subjected to histopathological examination.
Histopathologically diagnosed cases of ameloblastoma.
7.4. Exclusion criteria:
7.6. Does this study require any investigation or intervention to be conducted on patients?
7.7.Has ethical clearance been obtained from your institution?
Yet to be obtained.
8. LIST OF REFERENCES:
1.Francisco de Assis Caldas Pereira et al.Clinicopathological and demographic characteristics of ameloblastomas. 2010;25(3):250-255.
2.Geraldo MAIA CAMPOS.Ameloblastoma, a Behavioural and Histologic Paradox. Braz Dent Journal 1990;1(1);5-15.
3.Rajendran R, Sivapathasundraram B. Shafer’s textbook of oral pathology, 5th edition. Delhi: elsevier India 2008.
4. Neville B W, Dama D D, Allen C M, Bouqout J E.Oral and Maxilofacial pathology. II edition. Philadelphia: W B Saunders C.
5. Regezi J A Scuibba J, Jordan RCK :OralPathalogy – Clinical Pathological correlation IV edition , Philadelphia: W B Saun 2004,309- 322.
6. DoenjaHertog, Elisabeth Bloemena, Irene H A Artman, Isaac-der-Waal .Histopathology of ameloblastoma of the jaws. Med oral pathol Oral Cir Bucal.2012 Jan;17(1):76-82.
7.BhawnaGupta,Irulandyponniah. The pattern of odontogenic tumors in a government teaching hospital in the sounthern Indian state of Tamil Nadu.OralSurg Oral Med oral pathol oral Radiol Endod.2010;110:e32-e39..
8. Adebiyi et al :Clinicopathological analysis of histological variants of ameloblastoma in a Suburban Nigerian Population. Head and Face medicine 2006,2:42.
9. Ladeinde et al .Ameloblastoma: Analysis of 207 cases in a Nigerian teaching hospital.. Quintessence Int 2006;37:69-74.
10. Kessler HP .Intraosseousameloblastoma.OralMaxillofacialSurgClin Am2004;16:309-322.
9 .SIGNATURE OF THE CANDIDATE:
10. REMARKS OF THE GUIDE:
11.NAME AND DESIGNATION OF GUIDE/S:
Department of Oral and Maxillofacial Pathology .
V.S.Dental College and Hospital K. R.Road, Bangalore-560004