Article Type: Research
Received : Jan 10.2019
Accepted : Jan 19.2019
published : Jan 30.2019
Corresponding author: Dr. Cornelius Iyogun*, Department of Oral & Maxillofacial Pathology, University of Port Harcourt, Nigeria, Email: firstname.lastname@example.org
Article Type: Research
Received : Jan 10.2019
Accepted : Jan 19.2019
published : Jan 30.2019
Background:Benign epithelial odontogenic tumours are rare in children and adolescents, but can pose a significant diagnostic and therapeutic dilemma. The aim of this study was to evaluate and document the pattern of the histologically confirmed benign epithelial odontogenic tumours in University of Port Harcourt Teaching Hospital, (UPTH), Port Harcourt, Nigeria and to compare our finding with previous studies done in Nigeria and elsewhere.
Materials and Methods:This was a 10 year retrospective study from 2nd January, 2008 to 31st December, 2017 of all benign epithelial odontogenic tumours recorded in the histopathology registers and patient case notes of UPTH, Port Harcourt, Nigeria. The following variables were obtained; age, gender, laterality and histopathological subtype.
Results:Thirty two cases of benign epithelial odontogenic tumours in children and adolescents were diagnosed during the 10 year study period which represented 27.5% of the total 109 cases of tumours of oral cavity and jaws in Port Harcourt. The ages range from 7 to 18 years (mean age of 14.00, ±SD 2.54) and relative peak age of incidence occurred in the second decade with male to female ratio of 1:1.5. Mandible was the most common site of involvement and accounted for 27 cases (90%). Ameloblastoma accounted for the vast majority (26 cases, 81.3%) and adenomatoid odontogenic tumours constituted the remaining 18.8% of cases.
Conclusion:This study shows that ameloblastoma is the most prevalent benign epithelial odontogenic tumours in our setting and has a female predilection, affecting more adolescents than children. Our findings were more consistent with African reports but at variance with western world where odontoma is the most common subtype.
Key words:Odontogenic tumours, ameloblastoma, benign tumours.
Introduction: Odontogenic tumours are lesions derived from epithelial, ectomesenchymal and/or mesenchymal elements that still are, or have been, part of the tooth forming apparatus. The incidence rates vary widely across the globe largely attributed to geographical location, source of data and detection pattern[1, 2].
Ameloblastoma is a slow growing, locally invasive, epithelial odontogenic tumour of the jaws with a high rate of recurrence if not completely excised. They constituted 1% of tumors in head and neck region and around 11% of all odontogenic tumors. It usually occur over a wide age range and most cases are diagnosed between 30 and 60 years of age. They are rare in children (8.7 to 15%). There is no gender predilection and are usually asymptomatic until a swelling or facial asymmetry is observed[3, 4].
Adenomatoid odontogenic tumour is a benign slow growing neoplasm of epithelial origin composed of odontogenic epithelium in a variety of histoarcchitectural patterns, embedded in a mature connective tissue stroma. They usually accounted for 2.2 – 7.1% of all odontogenic tumours and more than two thirds are diagnosed in the 2nd decade and around 90% of cases are found before the age of 30 years, it is more common in female than male. Most of them are asymptomatic and some cases may present as a palpable bony-hard swelling with or without slight pain.
There are relatively few studies on odontogenic tumours in children and adolescents from various parts of Nigeria. The aim of this study was to evaluate and document the pattern of histologically confirmed benign odontogenic tumours in patients less than 20 years of age, and to compare our findings with those from previous series.
Materials and Methods:This was a 10 year retrospective study from 2nd January, 2008 to 31st December, 2017 of all benign epithelial odontogenictumors recorded in thehistopathology registers and patient case notes of the UPTH, Port Harcourt, Nigeria. The following variables were obtained; age, gender, laterality and histopathological subtype.
Histology slides on all benign epithelial odontogenic tumours were retrieved and reviewed by the study authors. Fresh sections were cut from archival paraffin blocks when slides could not be retrieved. All specimens had been fixed in 10% formal saline, and then routinely processed for paraffin embedding. Microtome sections were cut at 4µ and stained with haematoxylin and eosin. Diagnosis was based on World Health Organization classification of odontogenic tumours.7The data was subsequently analysed using SPSS version 20 and presented as frequency tables.
Results:A total of thirty cases of benign epithelial odontogenic tumours in children and adolescents were diagnosed during the 10 year study period which represented 27.5% of the total 109 cases of tumours of oral cavity and jaws in Port Harcourt. The overall age range was 7 to 18 years (mean age of 14.00, ±SD 2.54 years) and relative peak age of incidence occurred in the second decade with male to female ratio of 1:1.4. (Table 1) depicts the age, gender and frequency distribution of different histological subtypes of benign epithelial odontogenic tumours.
Mandible was the most common site of involvement and accounted for 27 cases (90%). Ameloblastoma accounted for the vast majority (26 cases, 86.7%); the peak age of incidence was in the second decade of life with mean age of 14 ±SD 2.77 years and male to female ratio of 1:1.4. Adenomatoid odontogenic tumours constituted the remaining 13.3% of cases, the peak age of incidence was also in the second decade of life with mean age of 13.5 ±SD 1.30 years and equal sex distribution. (Table 2) shows the anatomical site distribution of benign epithelial odontogenic tumours in children and adolescents.
Figures 1 & 2 show photomicrographs of ameloblastoma and adenomatoid odontogenic tumour respectively.
Fig 1: Ameloblastoma (H & E 20x)
Fig 2: Adenomatoid Odon Tumour (H&E 20x)
Discussion: A total of thirty cases of benign epithelial odontogenic tumours in children and adolescents were diagnosed during the 10 year study period which represented 27.5% of the total 109 cases of tumours of oral cavity and jaws in Port Harcourt. This corroborates some Nigerian reports, in Ibadan documented 25.9% and 32.7% respectively[8, 9]. While our figure was higher than 19.67% in Ghana, 9.5% in Israel, 18.4% and 19.3% in 2 separate studies in Lagos, Nigeria, it was much lower than Japanese series, 79.8% observed by Sato, 83.5% by Cohen and 84.5% by [10, 16].Thus, there appears to be no consistent pattern within and outside the country. This may be due to the varied denominators used to determine the rate; the upper limit of the age group may vary from 14 to 20 years. Another possible explanation is the differences in denominators used to obtain percentage incidence, while some used the total number of tumours observed in the population, others used the total number of jaw tumours which can affects the outcome. Related the variation to ethnic characteristics.
In this appraisal, patients age range from 7 to 18 years and peak age of incidence occurred in the second decade which is in agreement with reports from Lagos, Nigeria, Ghana and Jordan[10, 12, 20]. Several studies have shown that odontogenic tumour usually arise from remnants of dental lamina or enamel organ during tooth formation. In most permanent teeth, crown formation is completed by the age of 5 years, odontogenic tumours are thought to arise after crown formation[5, 6]. This may explain why the tumour was not seen in less than 5 years in this series.
This study found that female were more affected than male with female to male ratio of 1.3:1 which is in keeping with finding in Israel by . Reports from Nigeria, Ghana and Argentina however, documented a relatively higher male preponderance[8, 10, 17]. There is no clear explanation on this variation.
In this review, odontogenic tumours showed a striking predilection for mandible in 90% of cases, which is the main site reported in literature[10, 12, 13, 21]. However, In Jordanian study, maxilla was the preferred site in 64% of their cases.
The histological variants of odontogenic tumours in children and adolescents in this appraisal were predominantly ameloblastoma which comprised 87.5% of cases. This is in tandem with previous African reports but at variance with western world where odontoma is the most prevalent odontogenic tumour[10, 13, 22]. Several factors are likely responsible for the differences; poor access to modern dental facilities in most African communities and the fact that many private dental outfit performed surgeries without thorough investigations.
Ameloblastoma arise from remnants of odontogenic epithelium and times from gingival surface epithelium and lining of odontogenic cysts. The most common histologic types are the follicular and plexiform. The follicular pattern consists of islands of odontogenic epithelium within a fibrous stroma, while the plexiform pattern contains basal cells arranged in anastomosing strands with an inconspicuous stellate reticulum. The stroma is usually delicate with cyst-like degeneration. In this review, the peak age of incidence of ameloblastoma was in the second decade and mandible was the common site of involvement, these rhymes with other African reports[8, 12, 21]. There was slight female affectation which contrasts most other findings which documented equal gender distribution[23, 24].
Adenomatoid odontogenic tumours (AOT) are derived from complex system of dental laminae or its remnants and usually accounted for 2.2 – 7.1% of all odontogenic tumours. The characteristic histologic feature includes solid sheets of epithelial cells with scanty connective tissue stroma and duct like structures comprising a central lumen lined by columnar epithelium and usually filled with fibrillar or homogenous eosinophilic material. In this study, AOT was the next common odontogenic tumour which agrees with most African reports but at variance with findings of Northern Nigeria who documented AOT as the most common paediatric tumour of the jaws[10, 12, 25]. The equal sex distribution and higher mandibular involvement observed in this appraisal are at variance with previous series[10, 13, 19].
Our study has inherent limitations of retrospective hospitalbased reports. The study incorporated only specimens histologically analyzed at UPTH, Port Harcourt. Even though it’s the only institution at the time with such capacity, not all the specimens are likely submitted to the centre by virtue of the appended component charges that histological assessment incurred and the size of the study domain.
In conclusion, this study shows that ameloblastoma is the most prevalent benign epithelial odontogenic tumours in our setting and has a female predilection, affecting more adolescents than children. Our findings were more consistent with African reports but at variance with western world where odontoma is the most common subtype. Histology is paramount in making diagnosis of various odontogenic tumours.
1. Philipsen HP, Reichart PA. (2006) Classification of odontogenic tumours. A historical review.
J Oral Pathol Med; 35(9):525-9.
2. Sousa FB, Etges A, Corrêa L, Mesquita RA, Araújo NS. (2002) Pediatric oral lesions: a 15-year review from São Paulo,
Brazil. J ClinPediatr Dent; 26(4):413-8.
3. Reichart PA, Philipsen HP, Sonner S. (1995) Ameloblastoma: biological profile of 3677 cases. Eur J Cancer B Oral Oncol.
4. Ord RA, Blanchaert RH Jr, Nikitakis NG, Sauk JJ. (2002) Ameloblastoma in children. J Oral Maxillo-fac Surg.; 60:762–770.
5. Nomura M, Tanimoto K, Takata T, Shimosato T. (1992) Mandibular adenomatoid odontogenic tumor with unusual
clinicopathologic features. J Oral Maxillofac Surg.; 50:282–5.
6. Mohamed A, Singh AS, Raubenheimer EJ, Bouckaert MM. (2010) Adenomatoid odontogenic tumour: Review of
the literature and an analysis of 33 cases from South Africa. Int J Oral Maxillofac Surg.; 39:843–6.
7. Barnes L, Everson JW, Reichart P, Sidransky D, editors. (2005) World Health Organization classification of tumours.
Pathology and genetics of head and neck tumours. Lyon: IARC Press;. 284-327
8. Adebayo ET, Ajike SO, Adekeye EO. (2005) A review of 318 odontogenic tumors in Kaduna, Nigeria. J Oral Maxillofac Surg.;
9. Lawal AO, Adisa AO and Popoola BO. (2012) Odontogenic tumours in children and adolescents: A review of forty-eight cases.
Ann Ib Postgrad Med;11(1):7-11
10. Abdulai AE,Nuamah IK, GyasiRK.Jaw Tumours in Ghanaian Children and Adolescents – A Retrospective Study.
World Journal of Surgical, Medical and Radiation Oncology Volume 7.
11. Ulmansky M, Lustmann J, Balkin N. (1999) Tumors and tumor-like lesions of the oral cavity and related structures in
Israeli children. Int J Oral Maxillofac Surg.; 28:291–294.
12. Arotiba GT. (1996) A study of orofacial tumors in Nigerian children. J Oral Maxillofac Surg.; 54:34–38.
13. Adebayo E T, Ajike S O, Adekeye E O. (2001) Tumors and tumor-like lesions of the oral and perioral structures
of Nigerian children. Int. J. Oral Maxillofac. Surg.; 30:205–208.
14. Sato M, Tanaka N, Sato T, Amagasa T. (1997) Oral and maxillofacial tumours in children: a review.
Br J Oral Maxillofac Surg.; 35:92–95. Doi: 10.1016/S0266-4356(97)90682-3.
15. Cohen DM, Bhattacharyya I. (2004) Ameloblastic fibroma, ameloblastic fibro-odontoma, and odontoma.
Oral Maxillofac SurgClin North Am.; 16:375–84. doi: 10.1016/j.coms.2004.03.005
16. Tanaka N, Murata A, Yamaguchi A, Kohama G. (2004) Clinical features and management of oral and
maxillofacial tumors in children. Oral Surg Oral Med Oral Pathol Oral Radiol. X; 88:11–15.
17. Guerrisi M, Piloni MJ, Keszler A. (2007) Odontogenic tumors in children and adolescents. A 15-year retrospective
study in Argentina. Med Oral Patol Oral Cir Bucal; 12:E180–185.
18. Ajayi OF, Ladeinde AL, Adeyemo WL, Ogunlewe MO.(2004) Odontogenic tumors in Nigerian children and adolescents-
a retrospective study of 92 cases. World J SurgOncol. Nov 27, pp. 2–39.
19. Adebayo ET, Ajike SO, Adekeye EO. (2002) Odontogenic tumors in children and adolescents: a study of 78 Nigerian
cases. J Craniomaxillofac Surg.; 30:267–272.
20. Al-Khateeb T, AL Hadi Hamasha AA, Almasri NM. (2003) Oral and maxillofacial tumors in North Jordanian children and
adolescents: a retrospective analysis over 10 years. Int. J. Oral Maxillofac. Surg.; 32:78–83.
21. Arotiba GT, Arotiba JT, Olaitan AA, Ajayi OF. (1997) theadenomatoid odontogenic tumor: an analysis of 57 cases in
a black African population. J Oral Maxillofac Surg.; 55:146–148.
22. Jones AV, Franklin CD. (2006) an analysis of oral and maxillofacial pathology found in children over a 30-year period.
Int J Paediatr Dent; 16:19-30.
23. Tamme T, Tiigimäe J, Leibur E. (2010) Mandibular ameloblastoma: a 28-years retrospective study of the surgical
treatment results. Minerva Stomatol.; 59:637–643.
24. Sule AA, Iyogun CA and Adeyemi TE. (2016) An Audit of Histopathological pattern of Ameloblastomas in Kano,
Nigeria. Nig Dent J; 24(1):205-9.
25. Asamoa EO, Ayanlere AO, Olaitan AA, Adekeye EO. (1990) Paediatric tumors of the jaws in Northern Nigeria.
J CranioMaxillofac Surg.; 18:130–135.