Journal of Indian Academy of Oral Medicine and Radiology

CASE REPORT
Year
: 2018  |  Volume : 30  |  Issue : 2  |  Page : 185--188

Adenomatoid odontogenic tumor in mandible: A rare case


Syeda Shadab Farha1, Sonia Sodhi1, Sneha Patil2, Suraj Tambe3,  
1 Department of Oral Medicine and Radiology, CSMSS Dental College and Hospital, Aurangabad, India
2 Department of Oral Medicine and Radiology, Rural Dental College and Hospital, Loni, Maharashtra, India
3 Department of Prosthodontics, Rural Dental College and Hospital, Loni, Maharashtra, India

Correspondence Address:
Dr. Sneha Patil
33, Ashray Rameshwar Nagar, Gangapur Road, Nashik - 422 013, Maharashtra
India

Abstract

Adenomatoid odontogenic tumor is a benign (hamartomatous), noninvasive lesion with slow but progressive growth. It develops from the dental lamina or its remnants. There are two variants of this tumor: Central and Peripheral. Central variant further get classified as follicular and extrafollicular on the basis of its association with the unerrupted tooth. Clinically this tumor has resemblance with other odontogenic lesions like dentigerous cysts, ameloblastoma etc. Thus histopathological examination is an important aid to confirm its diagnosis. Here we report a rare case of follicular type of Adenomatoid odontogenic tumor associated with impacted mandibular premolar.



How to cite this article:
Farha SS, Sodhi S, Patil S, Tambe S. Adenomatoid odontogenic tumor in mandible: A rare case.J Indian Acad Oral Med Radiol 2018;30:185-188


How to cite this URL:
Farha SS, Sodhi S, Patil S, Tambe S. Adenomatoid odontogenic tumor in mandible: A rare case. J Indian Acad Oral Med Radiol [serial online] 2018 [cited 2022 Jan 26 ];30:185-188
Available from: https://www.jiaomr.in/text.asp?2018/30/2/185/236721


Full Text



 Introduction



The adenomatoid odontogenic tumor (AOT) is an uncommon odontogenic tumor with limited growth potential that arises from dental lamina or its remnants. It accounts only for 2.2–7.1% of all odontogenic tumors.[1] In 1969, Philipsen and Birn were the first who proposed a review on AOT, which was later included in the first classification of “Histological typing of odontogenic tumor” by World Health Organization (WHO) in 1971.[2] Philipsen et al. further categorized this tumor into three variants: follicular, extrafollicular, and peripheral on the basis of its clinical and radiographic appearance. Follicular variant (73%) is a central lesion that is associated with the unerupted tooth, while extrafollicular variant (24%) does not have connection with the embedded or unerupted tooth and peripheral variant (3%) occurs primarily in the gingival tissue of tooth-bearing areas.[3] All the three variants have similar histological appearance as they have common origin. This tumor is most commonly seen in young individuals (second to third decade), with female predilection (F:M = 2:1) most commonly affecting anterior maxilla.[3]

Here, we report a rare case of follicular type of AOT in a 19-year-old male patient in mandibular premolar region illustrating clinical, radiographical, and histological behavior of this tumor.

 Case Report



A 19-year-old male patient reported to Department of Oral Medicine and Radiology with a chief complaint of pain and swelling over right side of lower jaw since 1 month. Patient had no systemic diseases nor used any medication. There was no history of trauma, pain, discharge, lymphadenopathy, or any other symptoms related to the lesion. On extraoral examination, a well-defined swelling was evident over right parasymphysis region and extending to body of mandible measuring about 2 × 4 cm; superiorly the swelling extended till the level of corner of mouth to the lower border of mandible inferiorly and anteriorly about 1 cm from the midline to about 3 cm in front of the angle of mandible posteriorly [Figure 1] and [Figure 2]. The skin over the swelling appeared normal. The swelling was tender on palpation, hard in consistency, noncompressible, nondepressible, and immobile with no discharge was elicited. There was no paresthesia over mental region. Intraorally, the patient presented a painless, slowly increasing swelling in the mandibular right posterior region. Mucosa overlying the swelling was normal. The swelling was bony hard and non-tender on palpation. A mild buccolingual expansion was seen on the mandibular posterior alveolus in 43 to 46 region. There was missing first premolar with over-retained deciduous first molar in the same region [Figure 3].{Figure 1}{Figure 2}{Figure 3}

On the basis of the clinical findings along with the past records, provisional diagnosis of dentigerous cyst was made. Benign tumors such as ameloblastoma, calcifying epithelial odontogenic tumor, keratinizing cystic odontogenic tumor, and calcifying cystic odontogenic tumor can be considered in differential diagnosis. Patient already had lateral oblique radiograph and orthopantomograph as he visited to some dental hospital before. Lateral oblique view and orthopantomograph revealed presence of single, well-defined radiolucency with sclerotic border surrounding crown of the unerupted tooth in relation to 44. Root resorption was evident with 84, 45 and mesial root of 46. Slight divergent seen with the root of 45 [Figure 4]a and [Figure 4]b. Further, we advised Cone beam computed tomography (CBCT) for more details. CBCT showed single, well-defined mediolateral radiolucency of size 28.7 and supero-inferior diameter of 29.1 mm. Also, there was marked buccolingual expansion approximately of size 26.3 mm [Figure 5].{Figure 4}{Figure 5}

Histopathological examination was also carried out to confirm the diagnosis. Fine-needle aspiration yielded no fluid, whereas microscopy revealed multisized solid nodules of cuboidal and columnar epithelial cells forming nests or rosette-like structure with minimal stromal connective tissue and spindle-shaped cells in the spaces between the epithelial nodules, which are encapsulated with a thick, inflamed fibrous capsule. Ameloblast-like epithelial cells forming duct-like structures, eosinophilic amorphous tumor droplets among the epithelial cells, Liesegang ring formation, and eosinophilic amorphous amyloid-like deposits were observed [Figure 6]. Thus, the histopathological diagnosis of AOT was obtained.{Figure 6}

Surgical excision of the lesion was carried out [Figure 7] and the patient was kept under regular follow-up every month [Figure 8]. The patient has not shown any signs of recurrence in the 6 months follow-up period after surgery.{Figure 7}{Figure 8}

 Discussion



AOT is a rare benign, nonaggressive neoplasm of epithelial origin. It constitutes about 2–3% of all odontogenic tumors. According to 1992 WHO classification, it is defined as: “A tumor of odontogenic epithelium with duct like structures and with varying degrees of inductive change in the connective tissue. The tumor may be partly cystic, and in some cases the solid lesion may be present only as masses in the wall of a large cyst. It has been generally believed that the lesion is not a neoplasm.”[4] It has high female predilection in the age range of 20–30 years. Anterior maxilla is considered to be the most common site of occurrence in association with the impacted canine, but in our case the lesion is associated with impacted mandibular first premolar. AOT is also called “two-thirds tumor,” because two-thirds occur in young females, two-thirds of these cases occur in the maxilla, two-thirds of these tumors are associated with unerupted teeth, and two-thirds occur in canines.[5]

The lesions usually present as an asymptomatic swelling with cortical expansion. It is relatively small in size not exceeding 1–3 cm in diameter, as seen in this case. The teeth involved are generally impacted, and the adjacent teeth may show displacement of the teeth.

It can be found on routine radiographic examination or computed tomography. Newer imaging modalities such as CBCT can be more useful than the plain film radiography as these techniques are successful in revealing the spatial relationships of the lesion with adjacent anatomical structures. The follicular variant presents as a unilocular, well-defined radiolucency around, above, or superimposed on unerupted tooth, and that often resembles a cystic lesion such as dentigerous cyst, benign tumors such as ameloblastoma (unicystic variant), calcifying epithelial odontogenic tumor, keratinizing cystic odontogenic tumor, and calcifying cystic odontogenic tumor, which can be considered in differential diagnosis.[6] Ameloblastoma is more prevalent in mandibular molar and ramus region, whereas AOT is frequently present in canine premolar region of the jaw. Keratinizing cystic odontogenic tumor shows minimum bone expansion compared to other odontogenic lesions such as ameloblastoma, AOTs, dentigerous cysts, etc. Calcifying epithelial odontogenic tumors and calcifying cystic odontogenic tumor show evidence of calcifications within the tumors, which gives mixed radiolucent-radiopaque radiographically.[7] Case presented here shows single, well-defined radiolucency with sclerotic border enveloping impacted premolar, which was diagnosed clinically as a dentigerous cyst. Root resorption is rarely associated with AOT, whereas it is evident in this particular case.[8] Approximately 78% of AOT shows calcified deposits as discrete foci within radiolucency but in our case, there was no evidence of calcifications.[3]

According to WHO, it is a tumor of odontogenic epithelium with duct-like structures and with varying degrees of inductive changes in the connective tissue. Histological examination is must to differentiate AOT from other odontogenic lesions. All three variants of AOT have similar histological pattern. The tumor may appear partially cystic or as masses in the wall of a large cyst. It is composed of spindle-shaped or polygonal cells that form sheets and whorled masses in connective tissue stroma. The characteristic duct-like structures that are lined by a single row of columnar epithelium with polarized nuclei are present.[9] Most of the AOTs also show eosinophilic, uncalcified, and amorphous material known as “tumor droplets” as seen in this presented case.[3]

Various treatment modalities such as marsupialization or decompression, surgical enucleation, and curettage are recommended to remove the tumor surgically. But conservative surgical approach is preferred due to nonaggressive nature of this tumor. Thus surgical enucleation and curettage is the most preferred treatment modality.[10] In this case also, the lesion was removed by surgical enucleation along with disimpaction of the impacted premolar.

Patient has been kept on periodic follow-up since 6 months after the surgery with no evidence of recurrence in post operative panoramic radiograph [Figure 9]. The recurrence rate is as low as 0.2%, which is lower than other odontogenic tumors such as ameloblastoma. Thus, the prognosis is excellent when completely removed.[11]{Figure 9}

From this case report we conclude that the AOT should be considered as under differential diagnosis whenever clinician encounter swelling associated with over-retained deciduous tooth and/or unerupted permanent tooth irrespective of its location.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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