The occurrence and pattern of ameloblastoma in children and adolescents: an Indian institutional study of 41 years and review of the literature

Abstract

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.

Results

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 ).

Table 1
Age and gender distribution of ameloblastoma in children and young adolescents.
Age, years Male Female Total (%)
0–10 5 2 7 (17.9%)
11–18 21 11 32 (82.1%)
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.

Table 2
Clinical findings of ameloblastoma in children and young adolescents.
Case Age, years Sex Side Location Duration, months Perforation and associated impacted tooth
1 8 M Right Mandibular body ND No impacted tooth
2 14 F Right Mandibular body–angle–ramus 3 47
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
11 11 M Left Mandibular body 1.5 36
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
22 10 M Left Mandibular body–angle–ramus 1.5 36
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
32 17 M Left Mandibular body 4 37
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
M, male; F, female; ND, no data available.

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 ).

Fig. 1
Radiographs showing (A) multilocular radiolucency in the right mandibular molar–ramus–angle region with the impacted permanent second molar (case 2, unicystic ameloblastoma), and (B) multilocular radiolucency in the left mandibular molar–angle–ramus region without an impacted tooth (case 33, solid ameloblastoma).

Fig. 2
Radiograph showing (A) unilocular radiolucency in the left mandibular molar–angle–ramus region with displacement of the permanent second molar (case 19, unicystic ameloblastoma), and (B) unilocular radiolucency in the right mandibular canine–premolar region without an impacted tooth (case 26, solid ameloblastoma).

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 .

Table 3
Literature review of case series of ameloblastoma in children and adolescents.
Author
Daramola et al. Keszler and Dominguez Kahn Chidzonga Olaitan and Adekeye
Year 1975 1986 1989 1996 1996
Cases 16 8 38 20 30
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
Sex
Male 10 4 18 10 18
Female 6 4 20 10 12
M/F ratio 1.7:1 1:1 0.9:1 1:1 1.5:1
Location
Maxilla 1 0 0 1 0
Mandible 15 8 38 19 30
Peripheral 1
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%)
Radiography
Multilocular 11 0 10 17 23
Unilocular 5 8 26 3 7
Not known 2
Impacted teeth
Multilocular NA NA NA NA NA
Unilocular NA NA NA NA NA
Histopathology
Solid NA NA 6 20 NA
Unicystic NA NA 31 NA
Treatment and recurrence
Conservative 4 8 (1 lost) 29 (13 lost) 13
Recurrence NA 3 2
Resection 12 7 (2 lost) 20 16
Recurrence NA 1 NA
No treatment 2 1
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.
Year 1998 2002 2003 2005 2007
Cases 6 11 10 79 15
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
Sex
Male 3 4 4 45 9
Female 3 7 6 34 6
M/F ratio 1:1 0.6:1 0.7:1 1.3:1 1.5:1
Location
Maxilla 0 1 0 4 1
Mandible 6 10 10 75 14
Peripheral
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%)
Radiography
Multilocular 2 NA 5 47 5
Unilocular 4 NA 5 24 10
Not known 6
Impacted teeth
Multilocular NA NA NA 8 NA
Unilocular NA NA NA 5 NA
Histopathology
Solid 6 3 4 65 7
Unicystic 8 6 12 8
Treatment and recurrence
Conservative 6 9 (1 lost) 5 18 11
Recurrence 5 4 NA 3
Resection 2 (1 lost) 5 57 4
Recurrence NA
No treatment 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
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Jan 17, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on The occurrence and pattern of ameloblastoma in children and adolescents: an Indian institutional study of 41 years and review of the literature

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