Ameloblastoma in the paediatric age group is considered a rarity and it accounts for approximately 10–15% of all reported cases. This study assessed the clinical, radiological, and histopathological features of 39 cases of ameloblastoma in Indian children aged less than 18 years, seen over a 41-year period (1971–2011) in the Department of Oral Pathology, Nair Hospital Dental College, India. Out of 256 diagnosed cases of ameloblastoma, 39 (15.2%) occurred in patients ranging in age from 4.5 to 18 years (mean age 13.6 years; male-to-female ratio 2:1). All of the tumours were intraosseous, with a marked predilection for the mandible (97.4%), the body–angle–ramus being the most commonly involved site. Radiographically, 23 cases presented as unilocular radiolucency. Histologically, 20 cases presented as solid and 19 as unicystic ameloblastoma. The interesting finding of 10 solid ameloblastoma presenting as unilocular radiolucency and five cases of unicystic ameloblastoma manifesting as multilocular radiolucency suggests that solid ameloblastomas should be included in the differential diagnosis of unilocular radiolucency of the jaw in the paediatric age group.
Ameloblastoma, with rare exceptions, is a benign and slow growing but relentlessly infiltrative tumour composed of odontogenic epithelium with mature, fibrous stroma without odontogenic ectomesenchyme. Ameloblastoma represents 13–54% of all jaw tumours affecting all age groups, with a peak incidence in the third and fourth decade of life.
The tumour is considered a rarity in paediatric patients, accounting for approximately 10–15% of all reported cases of ameloblastoma. Since there is a paucity of information on the occurrence and pattern of ameloblastoma in children and young adolescents under 18 years of age in India, this article highlights the experience at our institution over the past 41 years (1971–2011). We also present a review of case series of patients with ameloblastoma in this age group. The purpose of the present study was to determine the occurrence and clinicopathological presentation of ameloblastoma in children and adolescents and to compare our findings with those reported in the relevant literature. This may contribute to a better understanding of this condition and further meta-analysis.
Materials and methods
A total of 256 histopathologically diagnosed cases of ameloblastoma were recorded in the Department of Oral Pathology, Nair Hospital Dental College, India between 1971 and 2011. The data of all patients aged under 18 years were recorded. Details of patient age, sex, location of the lesion, clinical features, radiographic appearance, histopathological features, treatment, follow-up, and recurrence were reviewed.
Sections that had been stained with haematoxylin and eosin, fixed in formalin and embedded in paraffin were also re-examined microscopically to ascertain the type of ameloblastoma – solid or unicystic. Unicystic ameloblastomas were classified as type 1, 2, or 3 using the criteria of Ackermann et al.
A Medline literature search restricted to case series of ameloblastoma affecting patients under 18 years of age for the period 1970–2013 was also done.
Out of 256 patients with ameloblastoma, 39 (15.2%) were included in the present study. There were 26 males and 13 females, giving a male-to-female ratio of 2:1 ( Table 1 ).
|Age, years||Male||Female||Total (%)|
|Total (%)||26 (66.7%)||13 (33.3%)||39|
At the time of diagnosis, age ranged from 4.5 to 18 years (mean 13.6 years); seven patients were under 11 years of age, while 32 patients were aged between 11 and 18 years. Age, sex, location of the lesion, and clinical features are summarized in Tables 1 and 2 . All lesions were intraosseous and there was a notable predilection for the mandible (97.4%); one case involved the anterior maxilla (2.6%). In the mandible, the body–angle–ramus (56.7%) was the most represented site. Although perforation of the bone was present in six patients, none of the cases showed infiltration of muscle and skin.
|Case||Age, years||Sex||Side||Location||Duration, months||Perforation and associated impacted tooth|
|1||8||M||Right||Mandibular body||ND||No impacted tooth|
|3||14||M||Crossing midline||Symphysis–parasymphysis||3||No impacted tooth|
|4||13||M||Right||Mandibular body–angle–ramus||3||No impacted tooth|
|5||4.5||M||Left||Mandibular body||ND||No impacted tooth|
|6||7||F||Crossing midline||Mandibular body||6||No impacted tooth|
|7||13||F||Right||Mandibular body||ND||No impacted tooth|
|8||13||F||Left||Mandibular body–angle–ramus||18||No impacted tooth|
|9||13||M||Left||Mandibular body–angle–ramus||6||No impacted tooth|
|10||13||F||Right||Mandibular body||6||No impacted tooth|
|12||13||M||Left||Mandibular body–angle–ramus||5||No impacted tooth|
|13||13||M||Left||Mandibular body||6||No impacted tooth|
|14||9||F||Right||Mandibular body–angle–ramus involving condyle and coronoid||ND||Perforation, no impacted tooth|
|15||14||F||Left||Symphysis–parasymphysis||2||No impacted tooth|
|16||13||M||Left||Mandibular body–angle–ramus||24||No impacted tooth|
|17||7||M||Crossing midline||Symphysis–parasymphysis||6||No impacted tooth|
|18||13||M||Left||Mandibular body||4||No impacted tooth|
|19||5||M||Left||Mandibular body–angle–ramus||ND||No impacted tooth|
|20||13||F||Right||Mandibular body–angle–ramus involving condyle and coronoid||6||45|
|21||13||F||Right||Mandibular body–angle–ramus||24||Perforation, no impacted tooth|
|23||18||M||Right||Mandibular body–angle–ramus||12||No impacted tooth|
|24||16||M||Crossing midline||Anterior maxilla||5||Perforation, no impacted tooth|
|25||18||F||Crossing midline||Symphysis–parasymphysis||18||No impacted tooth|
|26||16||M||Right||Mandibular body||12||No impacted tooth|
|27||18||M||Right||Symphysis–parasymphysis||ND||No impacted tooth|
|28||18||M||Left||Mandibular body–angle–ramus involving condyle and coronoid||6||45|
|29||17||M||Left||Mandibular body–angle–ramus||2||No impacted tooth|
|30||18||M||Right||Mandibular body||6||Perforation, no impacted tooth|
|31||16||M||ND||Mandibular body||8||No impacted tooth|
|33||17||F||Left||Mandibular body–angle–ramus||9||Perforation, no impacted tooth|
|34||18||F||Right||Mandibular body–angle–ramus||6||No impacted tooth|
|35||16||M||Right||Mandibular body–angle–ramus||2||No impacted tooth|
|36||18||F||Left||Mandibular body–angle–ramus||24||No impacted tooth|
|37||15||M||Right||Mandibular body–angle–ramus||2.5||Perforation, no impacted tooth|
|38||15||M||Left||Mandibular body–angle–ramus involving coronoid||3||37|
|39||15||M||Left||Mandibular body–angle–ramus||1.5||No impacted tooth|
Extraorally, a slow-growing swelling causing facial deformity was the most common finding. Intraorally, cortical expansion and mobility of the teeth in the affected area were the most common findings. Pain was seldom the main complaint. Three out of 39 patients experienced a loss of sensation at the lesion site. None of the patients had any demonstrable difficulty in mastication or speech. The duration of clinical symptoms prior to diagnosis varied from 2 months to 2 years. The delay was mainly due to the unwillingness of some patients to undergo surgical treatment.
Plain radiographic examinations revealed multilocular radiolucencies in 12 of the 39 cases (30.7%) and unilocular radiolucencies in 23 (59.0%); one case (2.6%) showed a mixed radio-opaque/radiolucent lesion. Radiographs were not available for three cases (7.7%). Seven cases (17.9%; two solid, five cystic) showed impacted teeth associated with the lesion (Figs 1 and 2 ).
On histopathological examination, 20 of 39 cases (51.3%) exhibited the solid variant and 19 (48.7%) showed the unicystic type of ameloblastoma. Of the 20 solid tumours, four were follicular and 16 were plexiform type. Using the histological criteria of Ackermann et al. for the 19 unicystic ameloblastomas, six were type 1, three type 2, four type 3, and three type 2 + 3 combined. For three of the cases only an incisional biopsy was received, hence histological typing was not considered. Peripheral ameloblastoma was not observed in our series.
On correlating radiographic findings with histological type, we made an interesting observation: 10 cases (10/23, 43.5%) of solid ameloblastoma presenting as a well-defined unilocular radiolucency and five cases (5/12, 41.7%) of unicystic ameloblastoma exhibiting multilocular radiolucency.
Eighteen patients (five solid, 13 unicystic) underwent conservative surgical treatment (enucleation plus peripheral ostectomy) and 15 patients (12 solid, three unicystic) underwent resection (segmental or hemi-mandibulectomy and bone graft/surgical plates). Six patients failed to attend their appointments.
Follow-up data were available for only one patient. This patient had plexiform ameloblastoma and experienced recurrence as granular cell ameloblastoma after 11 years.
In our search of the literature in Medline (1970–2013), ameloblastoma in the paediatric population was found to be rare. Relevant series are described in Table 3 .
|Daramola et al.||Keszler and Dominguez||Kahn||Chidzonga||Olaitan and Adekeye|
|Occurrence||16/70, 22.9%||8/92, 8.7%||38/311, 12.2%||20/117, 17.1%||30/206, 14.6%|
|Age range, years||5–17||4–15||7–19||11–18||NA–17|
|Common site||Symphyseal (7/16, 43.8%)||Molar–ramus (4/8, 50%)||Molar–ramus (29/36, 80.5%)||Symphyseal (7/19, 36.8%)||Body (14/30, 46.7%)|
|Treatment and recurrence|
|Conservative||4||8 (1 lost)||29 (13 lost)||–||13|
|Resection||12||–||7 (2 lost)||20||16|
|Follow-up||–||5 months to 4 years||6 months to 19 years (18 lost)||–||6 months to 9 years|
|Takahashi et al.||Ord et al.||Al-Khateeb and Ababneh||Arotiba et al.||Huang et al.|
|Occurrence||6/27, 22.2%||11/38, 28.9%||10/26, 38.5%||79/360, 21.9%||15/223, 6.7%|
|Age range, years||8–15||12–19||9–20||6–19||6–19|
|Common site||Angle–ramus (3/6, 50%)||Angle–ramus (5/11, 45.5%)||Molar–ramus (5/10, 50%)||Posterior region (31/73, 42.5%)||Body–angle–ramus (10/15, 66.7%)|
|Treatment and recurrence|
|Conservative||6||9 (1 lost)||5||18||11|
|Resection||–||2 (1 lost)||5||57||4|
|Follow-up||4.4–11.8 years||5 months to 7 years||4–13 years (1 lost)||1 month to 5 years (most lost)||2–17 years|