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CASE REPORT
Year : 2013  |  Volume : 40  |  Issue : 1  |  Page : 52-56

Surgical management of maxillary adenomatoid odontogenic tumor in paediatric patient: A clinical report


1 Department of Oral and Maxillofacial Surgery, Kalka Dental College and Hospital, Meerut, India
2 Department of Pedodontics and Preventive Dentistry, Kalka Dental College and Hospital, Meerut, India
3 Department of Prosthodontics, Shree Bankey Bihari Dental College, Ghaziabad, Uttar Pradesh, India
4 Department of Oral Pathology, Kalka Dental College and Hospital, Meerut, India

Date of Web Publication28-Mar-2013

Correspondence Address:
Prince Kumar
Department of Prosthodontics, Shree Bankey Bihari Dental College and Research Centre, Ghaziabad - 201 302, Uttar Pradesh
India
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DOI: 10.4103/0974-5009.109710

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  Abstract 

Adenomatoid odontogenic tumor (AOT) is a rare odontogenic tumour that is frequently misdiagnosed as odontogenic cyst. It is a tumor lined by odontogenic epithelium in a variety of histoarchitectural patterns, which are embedded in a mature connective tissue stroma. It is mostly seen in young patients with a greater predilection for females. Maxillary arch is the predilection site of occurrence, most commonly associated with an unerupted maxillary canine. It presents as a symptom-free lesion and is frequently discovered during routine radiographic examination. It is seen more frequently in female than in male patients. This rare tumor resembles other odontogenic cysts and tumors such as dentigerous cyst or ameloblastoma. The treatment for AOT is conservative and the prognosis has always been good. This article discusses the surgical management of an AOT in the maxilla in paediatric patient.

Keywords: Adenomatoid odontogenic tumour, extra follicular, impacted canine


How to cite this article:
Yadav S, Tyagi S, Kumar P, Puri N. Surgical management of maxillary adenomatoid odontogenic tumor in paediatric patient: A clinical report. J Sci Soc 2013;40:52-6

How to cite this URL:
Yadav S, Tyagi S, Kumar P, Puri N. Surgical management of maxillary adenomatoid odontogenic tumor in paediatric patient: A clinical report. J Sci Soc [serial online] 2013 [cited 2014 Aug 21];40:52-6. Available from: http://www.jscisociety.com/text.asp?2013/40/1/52/109710


  Introduction Top


The Adenomatoid Odontogenic Tumor (AOT) is a rare, slow growing, benign, odontogenic epithelial tumor with characteristic clinical and histological features, which usually arise in the second or third decade. In a series of publications, it has been clarified that the adenomatoid tumor (AOT) constitutes an entity within the odontogenic tumors, clearly distinguishable from the classic intraosseous, infiltrative ameloblastoma. [1] The tumor affects females more than males in almost a two to one ratio. The maxilla is involved nearly twice as frequently as the mandible, of which the canine region is the most commonly involved region. [2],[3] It was suggested to abandon the previously used term adeno-ameloblastoma, and Philipsen and Birn introduced the above term (AOT), which was adopted by the WHO classification in 1971. [1],[4]

The benign (hamartomatous) noninvasive AOT appears in three clinicotopographic variants: (1) Follicular, (2) extrafollicular, and (3) peripheral. Follicular and extrafollicular variants are both intrabony or central tumors and account for 97% of all AOTs, of which 73% are of the follicular type. [5] The extrafollicular variant is not associated with an unerupted tooth like the follicular variant, and the well-defined, unilocular radiolucency is found between, above, or superimposed on the roots of erupted teeth. It is characteristic that the rare subvariant mimicking a periapical lesion is, in fact, located palatally (or lingually) to the "involved" tooth. [6] Sixty-nine percent of AOTs are diagnosed in the second decade of life, and more than half of the cases (53%) occur during the teenage years (13 to 19 years of age). [7]

Microscopically, AOT exhibits tubular characteristic and duct-like structures that led to the term "adenoameloblastoma," which previously used to designate this lesion. [8] In the latest edition of WHO classification of odontogenic tumors in 2005, AOT was classified into the first group of tumors (odontogenic epithelium without ectomesenchyme) instead of the second group (odontogenic epithelium with ectomesenchyme). [9] Because of the absence of ectomesenchyme in immunohistochemical staining, dysplastic dentin, AOT is now considered the result of ametaplastic process rather than epithelial-ectomesenchyme interaction. [10]


  Case Report Top


A 6.5-year-old male patient was referred to the department of maxillofacial surgery with a chief complain of swelling in the maxillary alveolar region. The medical history was non contributory. The patient was asymptomatic and in good general health. Intraoral examination disclosed a nontender expansion of the left maxilla, covered by normal mucosa [Figure 1]a, b and c. The patient had no nerve deficit or adenopathy in the face or neck. An orthopantomogram revealed the presence of a significant unilocular radiolucent area with well-defined sclerotic borders, involving an embedded upper left permanent canine and second premolar. Radiographically, the first permanent premolar was found to be missing [Figure 2].
Figure 1:

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Figure 2: Orthopantomogram

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Extraorally, the swelling was located in the maxillary region on the left side lateral to the nose just below the malar process [Figure 1]a resulting in facial asymmetry. The swelling was irregular in shape and measured approximately 3cm × 4 cm, extending superiorly up to the malar process, anteriorly up to left nasolabial fold, laterally up to malar process and inferiorly to the alveolar process involving deciduous 1 st and 2 nd deciduous molar. On palpation, the swelling was non pulsatile, non tender, non fluctuant, and bony hard in consistency. The surgery was performed under general anaesthesia. The triangular flap was designed to expose the lesion on the facial aspect of the maxilla. The bone appeared to be thinned but was intact. Below the bone, a reddish, bulky layer of a cystic tumor became evident [Figure 3] and was removed [Figure 4]. There were no apparent infiltrations of the surrounding bones [Figure 5]. The impacted permanent canine and second premolar was found to be embedded in the lesion. The deciduous 1 st and 2 nd molars were also extracted because of their association with the lesion. The oral defect was closed by primary intention [Figure 6]. Healing was uneventful. The follow-up examination after one year revealed no recurrence [Figure 7] and [Figure 8].
Figure 3: Surgical exposure of lesion

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Figure 4: Excised lesion

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Figure 5: Surgical exposure of the defect

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Tumor tissue was completely embedded in paraffin. Four-μm thick sections were cut and stained with hematoxylin-eosin, PAS (periodic acid Schiff), Giemsa, Elastica van Gieson, and Congo Red. Pathological analysis revealed cystic formation with smooth solid nodular areas adjacent to the retained tooth. Histologically, solid appearing masses revealed typical finding of AOT with peripheral narrow strands of smaller cells [Figure 9], which formed net-like proliferation and cribriform structures both at the base of nodules and between them. More superficially, two-to four-cell layer forming broad zones of fusiform cells with oval nuclei and bright cytoplasm were detected. The overall features confirmed the diagnosis of adenomatoid odontogenic tumor.
Figure 6: Primary closure of lesion

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Figure 7: Post operative intraoral view

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Figure 8: Post operative facial view

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Figure 9: Histopathological confirmation of the lesion (AOT)

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  Discussion Top


The adenomatoid odontogenic tumor (AOT) is an infrequent benign epithelial tumor, preferentially found in children and young adults. [11] Both intraosseous and extraosseous forms are distinguished. The subtyping of AOT is based on clinical and radiological findings. The follicular (intraosseous) type is by far the most frequent growth type of AOT. [11] In the case of follicular growth type, the tumor is localized around the crown of a retained tooth and additionally may cover the upper part of the dental root. In the current case, the cystlike tumor covered the tooth completely, giving access to the hard tissue after intended incision of the resection specimen. The gross macroscopic appearance of the tumor is in accordance with former definitions of the entity recommended by the WHO: The AOT may be "partly cystic and in some cases the solid lesion may be present only as masses in the wall of a large cyst", as in this case. [11],[12]

On radiographs, the intraosseous follicular variant of AOT shows a well-delineated, uni-locular radiolucency sourrounding the crown of a retained tooth, a picture indistinguishable from follicular cysts. Indeed, the radiological findings of AOT frequently share characteristics of other odontogenic lesions such as dentigerous cyst, calcifying odontogenic cyst or tumor, ameloblastoma, keratocystic odontogenic tumor, or periapical disease. [13] Minute radiopacities around the retained tooth may be found in AOT and are considered a characteristic but not pathognomonic finding. [11]

This presented report on the case of an AOT demonstrates immunohistochemical findings characterized by a cytokeratin profile resembling follicular cysts and gingival epithelium. It was in accordance with an earlier report illustrating similar immunohistochemical picture. [14] Moreover, the comparison was based on the knowledge of AOT immunoreactivity for cytokeratin subtypes, which shows some zonal differences within neoplastic nodules. In the present case, immunoreactivity was found for cytokeratins and focal coexpression of vimentin and, surprisingly, also of SMA at the base of the broad duct-like zone. Mineralized and hyaline material does not show immunohistochemical reactivity for cytokeratin, as to be expected. [15] In vitro, the coexpression of cytokeratin and vimentin of oral epithelia is well known. [16]


  Conclusion Top


Adenomatoid odontogenic tumor is a rare benign epithelial odontogenic tumor that can be treated by local excision. Expert morphological diagnosis is required to establish differential diagnosis, in particular from ameloblastoma, thus preventing extensive surgery. Immunohistochemical investigations validate cytoskeletal characteristics, which this entity shares with odontogenic cysts. The identification of α-SMA in a small population of tumor cells points to a myoepithelial differentiation of a subset of the tumor.


  Acknowledgment Top


The authors would like to express gratitude to their colleagues especially Dr. Prince Kumar, for help regarding designing and editing of the manuscript.

 
  References Top

1.Siar CH, Ng KH, Murugasu P. Adenomatoid odontogenic tumor: Gross and histological examination of 45 cases. Singapore Med J 1987;28:180-9.  Back to cited text no. 1
    
2.Sato D, Matsuzaka K, Yama M, Kakizawa T, Inoue T. Adenomatoid odontogenic tumor arising from the mandibular molar region: A case report and review of literature. Bull Tokyo Dent Coll 2004;45:223-7.  Back to cited text no. 2
    
3.Dayi E, Gürbüz G, Bilge OM, Ciftcioðlu MA. Adenomatoid odontogenic tumour (adenoameloblastoma). Case report and review of literature. Aust Dent J 1997;42:315-8.  Back to cited text no. 3
    
4.Pindborg JJ, Kramer IRH. International histological classification of tumours: No. 5. Histological typing of odontogenic tumours, jaw cysts, and allied lesions. Geneva: World Health Organization, 1971.  Back to cited text no. 4
    
5.Philipsen HP, Reichart PA, Zhang KH, Nikai H, Yu QX. Adenomatoid odontogenic tumour: Biological profile based on 499 cases. J Oral Pathol Med 1991;20:149-58.  Back to cited text no. 5
    
6.Philipsen HP, Reichart PA. Adenomatoid odontogenic tumour: Facts and figures. Oral Oncol 1999;35:125-31.  Back to cited text no. 6
    
7.Philipsen HP, Reichart PA, Nikai H. The adenomatoid odontogenic tumour (AOT): An update. J Oral Pathol Med 1997;2:55-60.  Back to cited text no. 7
    
8.Neville BW, Damm DD, Allen CM, Bouquot JE. Oral and maxillofacial pathology. In: Warldon CA, Odontogenic Cysts and Tumors. 2 nd ed, Philadelphia: WB Saunders; 2002. p. 589-642.  Back to cited text no. 8
    
9.Jing W, Xuan M, Lin Y, Wu L, Liu L, Zheng X, et al. Odontogenic tumours: A retrospective study of 1642 cases in a Chinese population. Int J Oral Maxillofac Surg 2007;36:20-5.  Back to cited text no. 9
    
10.Evans BL, Carr RF, Phillipe RJ. Adenoid ameloblastoma with dentinoid: A case report. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;98:583-8.  Back to cited text no. 10
    
11.Reichart PA, Philipsen HP. Odontogenic Tumors and Allied Lesions. London: Quintessence Publishing Co. Ltd.; 2004. p. 105-15.  Back to cited text no. 11
    
12.Kramer IRH, Pindborg JJ, Shear M. International histological classification of tumours: histological typing of odontogenic tumows. 2 nd ed. Heidelberg: Springer-Verlag, 1992.  Back to cited text no. 12
    
13.Konouchi H, Asaumi J, Yanagi Y, Hisatomi M, Kishi K. Adenomatoid odontogenic tumor: Correlation of MRI with histopathological findings. Eur J Radiol 2002;1:19-23.  Back to cited text no. 13
    
14.Philipsen HP, Srisuwan T, Reichart PA. Adenomatoid odontogenic tumor mimicking a periapical (radicular) cyst: A case report. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002;94:246-8.  Back to cited text no. 14
    
15.Leon JE, Mata GM, Fregnani ER, Carlos-Bregni R, de Almeida OP, Mosqueda-Taylor A, et al. Clinicopathological and immunohistochemical study of 39 cases of adenomatoid odontogenic tumour: A multicentric study. Oral Oncol 2005;41:835-42.  Back to cited text no. 15
    
16.Larsson A, Swartz K, Heikinheimo K. A case of multiple AOT-like jawbone lesions in a young patient: A new odontogenic entity? J Oral Pathol Med 2003;32:55-62.  Back to cited text no. 16
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9]



 

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Case Report
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