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Year : 2014  |  Volume : 57  |  Issue : 2  |  Page : 290-293
Adenomatoid odontogenic tumor with clear cell changes

1 Department of Oral Pathology and Microbiology, Institute of Dental Sciences, Bhubaneswar, Odisha, India
2 Department of Oral Pathology and Microbiology, M. G. M. Dental College and Hospital, Navi Mumbai, Maharastra, India
3 Department of Dentistry, Y. C. M Hospital, Pimpri, Pune, Maharastra, India

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Date of Web Publication19-Jun-2014


Adenomatoid odontogenic tumor (AOT) has a limited biological profile and been an attention-grabbing tumor for a century for its origin. Though described earlier, it was widely accepted after Harbitz from Norway reported about this uncommon benign tumor in 1915. There has been a long debate as whether this tumor is a hamartoma or a neoplasm. Here, we present a case of AOT in a 20-year-old female with details of clinical, radiological and histological features along with clear cell changes, signifying AOT to be more aggressive in nature than assessed from earlier literature. Thus, we did an extensive search of PubMed literature on AOT with all its histopathological features associated until date to find the report of clear cell changes yet.

Keywords: Adenomatoid odontogenic tumor, clear cell changes, hamartoma, neoplasm

How to cite this article:
Mohanty N, Routray S, Swain N, Ingale Y. Adenomatoid odontogenic tumor with clear cell changes. Indian J Pathol Microbiol 2014;57:290-3

How to cite this URL:
Mohanty N, Routray S, Swain N, Ingale Y. Adenomatoid odontogenic tumor with clear cell changes. Indian J Pathol Microbiol [serial online] 2014 [cited 2023 Sep 26];57:290-3. Available from:

   Introduction Top

Historical background of "adenomatoid odontogenic tumor (AOT)" verifies it to be termed as "pseudoadenoameloblastinoma," "cystic adamantoma," "adamantinoma of the maxilla," etc. over the years. Staphne in 1948 first recognized AOT as a distinct pathological entity. [1] The term "AOT" came into acceptance in the World Health Organization (WHO) classification of odontogenic tumors in 1971 proposed by Philipsen and Birn. Ide et al., has proposed a more expanded and revised history of AOT in their recent paper making it a complete review. [2] The WHO definition of AOT is "a tumor composed of odontogenic epithelium presenting a variety of histoarchitectural patterns, embedded in a mature connective tissue stroma, and characterized by slow but progressive growth." [3] The AOT accounts for 2.2-7.1% of odontogenic tumors, which affects predominantly the jaws of female adolescents especially maxilla. [4]

Relevant literature for AOT cases was identified by searching PubMed (Medline) database. The word "AOT" yielded 264 results out of which many reported cases mentioned about some distinct feature associated with AOT, may it be of clinical, radiographical or histopathological relevance. Hence, we the authors take the opportunity to report a case with a new distinct finding of pathological relevance and review of literature with the same.

   Case report Top

A 20-year-old female patient was referred to our outpatient department for evaluation of an asymptomatic swelling in left maxilla that was present since 3 months. Her medical history was otherwise non-contributory to the chief complain. Clinically, the area was grossly deformed though skin over the lesion appeared normal. There was no sensory deficit or nasal discharge observed. Intraoral examination revealed expansion of both buccal and palatal cortical plates of the left maxilla from deciduous canine to third molar region with intact overlying mucosa. Panoramic radiograph showed a unilocular radiolucency extending from distal root surface of 21 up to maxillary tuberosity region with impacted 23. Root displacement of 22 and resorption of roots of retained 63, 24, and 25, 26, 27, 28 were also evident [Figure 1]a]. Magnetic resonance imaging scan showed a hyper-radiolucency of 6 cm × 4 cm having comparatively clear demarcation with encroachment of maxillary sinus and erosion of the lateral wall of nose [Figure 1]b]. Odontogenic lesions, especially the radicular cyst, odontogenic keratocyst, ameloblastoma, AOT, ameloblastic fibroma, myxoma, and glandular odontogenic cyst were high on our differential diagnosis as this lesion was noted in the tooth-bearing area of the jaws. Complete extirpation of the lesion was done and submitted for histopathological examination [Figure 2]a].
Figure 1: (a) Panaromic view of the lesion showing radiolucency in left maxilla area showing resorption of roots. (b) Magnetic resonance imaging scan of the lesion shows well demarcated radiolucency and encroachment of maxillary sinus along with erosion of lateral wall of nose

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Macroscopically, the specimen appeared as a solid mass with dimensions of approximately 4.5 cm × 3.5 cm × 4.0 cm with a smooth surface and associated with a well-developed canine crown portion, circumscribed by cyst [Figure 2]b].
Figure 2: (a) Intra-operative picture showing procedure of enucleation of the capsular mass. (b) Gross specimen received by the histopathologist for processing

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Microscopically, the lesional tissue contained a cystic cavity with variable-sized solid nodules of columnar cells of odontogenic epithelium forming nests and rosette like structures [Figure 3]a]. Between the epithelial cells and in the center of the rosette-like configurations, eosinophilic amorphous material "tumor droplets" was present. The duct-like spaces were also seen and were lined by a single row of columnar epithelial cells, with the nuclei polarized away from luminal surface. Connective tissue was fibrocellular with areas of hyalinization. In some areas of this solid nodule like areas, clear cell changes were found which has yet not been reported as a common histopathological feature in AOT [Figure 3]b]. Periodic acid-Schiff (PAS) stain was done and the clear cell origin was confirmed [Figure 4].
Figure 3: (a) H and E view of solid tumor islands arranged in rosette pattern in some areas at ×4 magnification. (b) H and E view of areas with clear cell changes seen under ×10 magnification

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Figure 4: Periodic acid-Schiff stain showed positivity for clear cells

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   Discussion Top

AOT is a common odontogenic tumor, most often diagnosed in the second decade of life, has more predilections for women and anterior maxilla. According to Philipsen and Reichart, the AOT appears in three clinico-topographic variants: Follicular, extra-follicular and peripheral. The follicular and extra-follicular variants are both intra bony and account for approximately 96% of all AOTs of which 71% are of the follicular type. [5] The radiographic findings of AOT has differential diagnosis of other odontogenic lesions such as dentigerous cysts, calcifying odontogenic cysts, calcifying odontogenic tumors, ameloblastomas, odontogenic keratocysts and periapical disease whereas all variants of AOT show identical histolopathological features. AOT has been reported to occur along with many types of cysts and neoplasms including dentigerous cyst, calcifying odontogenic cyst, odontoma, and ameloblastoma. [6] Immunohistochemically, the classical AOT phenotype is characterized by positive staining with cytokeratin 5 (CK5), CK17 and CK19 and is negative for CK4, CK10, CK13 and CK18. Recently, Crivelini et al. detected the expression of CK14 in AOT adding a new insight to its origin indicating the reduced dental epithelium. [7]

The controversy as to whether AOT represents hamartoma-like odontomas or a true neoplasm still persists. [8],[9],[10] Recently, Marx and Stern, in their book argued, this lesion to be a cyst rather than a tumor or hamartoma. They described AOT as a cyst that has hamartomatous intraluminal proliferation of epithelial cells derived from Hertwig epithelial root sheath. Calcifications seen in the histopathological picture are thought to be root dentin induced by root sheath epithelium. [11] Interestingly, we noticed the presence of pigmented cells in AOT during reviewing the literature, where racial pigmentation probably plays an important role. [1],[8],[9],[10],[11],[12] So an extensive review of literature in the last decade did reveal a lot of diverse histologic features in AOT, considering it to be either hybrid lesions or arising along with other lesions [Table 1]. [13],[18],[19],[20],[21],[22] As earlier reviewed by Mutalik et al., of various histopathological patterns in AOT (about 20 in number), inclusive of features seen in their case such as calcifications representing CEOT like areas, hyalinization, dentinoid like areas, etc., but clear cell changes was still not reported. [23] In the present case, the most distinct feature found was clear cell changes in the lesional tissue. Clear cell change can be an indication of the process of cellular degeneration or its odontogenic epithelial origin (diastase digestion PAS positive glycogen content). We did not find any literature earlier reporting AOT with clear cell changes making our case as the first to be reported. As already clear cell change has been associated to aggressive behavior of the lesion, AOT could be considered as a neoplasm after this finding.
Table 1: Review of AO T reported cases with unique histological findings in last decade

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Despite the ongoing debate on nomenclature, origin of AOT and its diversified histopathological nature, conservative surgical enucleation is the treatment modality of choice as its well established benign course and easy separation of the lesion from its bony crypt because of its thick capsule. [4],[5],[6],[7],[8],[9],[10] In the present case, though the defect was quite extensive, the surgeons followed the usual protocol of enucleation and closed the defect with bone regeneration graft material. Patient follow-up was done for a year which showed radiopaque areas in gradual follow-up with OPG confirming the reduction in bony defect.

   Conclusion Top

Interestingly, the present case had unusual clinical and radiological findings features in contrast to most normal types of AOT supporting its neoplastic behavior. Firstly, in addition to large size with encroachment of maxillary sinus and lateral wall of nose, rapid growth indicates its aggressive behavior. Secondly, the lesion was associated with resorption of multiple teeth which is quite uncommon in AOT as very few similar cases have been reported. Thus, based on clinical findings of the present case indicating aggressive biological behavior, we support the hypothesis suggesting AOT as a neoplasm rather than cyst or hamartoma. Due to the clear cell changes observed, the patient was under customary follow-up for aggressive tendency or recurrence. To conclude though AOT might be under the scanner of controversies, the treatment irrespective of its size and origin remains the same and can be attributed to its capsular nature, but newer techniques considering its histopathological behavior shall be also well thought-out.

   References Top

1.Handschel JG, Depprich RA, Zimmermann AC, Braunstein S, Kübler NR. Adenomatoid odontogenic tumor of the mandible: Review of the literature and report of a rare case. Head Face Med 2005;1:3.  Back to cited text no. 1
2.Ide F, Muramatsu T, Ito Y, Kikuchi K, Miyazaki Y, Saito I, et al. An expanded and revised early history of the adenomatoid odontogenic tumor. Oral Surg Oral Med Oral Pathol Oral Radiol 2013;115:646-51.  Back to cited text no. 2
3.Barnes L, Eveson JW, Reichart P, Sidransky D, editors. World Health Organization Classification, Tumours Pathology and Genetics, Head and Neck Tumours. Lyon, France: IARC Press; 2005.  Back to cited text no. 3
4.Philipsen HP, Reichart PA, Zhang KH, Nikai H, Yu QX. Adenomatoid odontogenic tumor: Biologic profile based on 499 cases. J Oral Pathol Med 1991;20:149-58.  Back to cited text no. 4
5.Philipsen HP, Reichart PA. Adenomatoid odontogenic tumour: Facts and figures. Oral Oncol 1999;35:125-31.  Back to cited text no. 5
6.Rick GM. Adenomatoid odontogenic tumor. Oral Maxillofac Surg Clin North Am 2004;16:333-54.  Back to cited text no. 6
7.Crivelini MM, de Araújo VC, de Sousa SO, de Araújo NS. Cytokeratins in epithelia of odontogenic neoplasms. Oral Dis 2003;9:1-6.  Back to cited text no. 7
8.Tjioe KC, Oliveira DT, Poleti ML, Ferreira O, Sant'Anna E, Gonçales ES. Adenomatoid odontogenic tumour displacing multiple teeth in an adolescent. Open J Stomatol 2012;2:146-8.  Back to cited text no. 8
9.Garg D, Palaskar S, Shetty VP, Bhushan A. Adenomatoid odontogenic tumor - hamartoma or true neoplasm: A case report. J Oral Sci 2009;51:155-9.  Back to cited text no. 9
10.Buchner A, David R, Carpenter W, Leider A. Pigmented lateral periodontal cyst and other pigmented odontogenic lesions. Oral Dis 1996;2:299-302.  Back to cited text no. 10
11.Marx RE, Stern D. Oral and Maxillofacial Pathology. A Rationale for Diagnosis and Treatment. Vol. II. Illinois: Quintessence Publishing Co., Inc.; 2012. p. 639-42.  Back to cited text no. 11
12.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. 12
13.Jivan V, Altini M, Meer S, Mahomed F. Adenomatoid odontogenic tumor (AOT) originating in a unicystic ameloblastoma: A case report. Head Neck Pathol 2007;1:146-9.  Back to cited text no. 13
14.Santos JN, Lima FO, Romério P, Souza VF. Adenomatoid odontogenic tumor: An unusual case exhibiting cribriform aspect. Quintessence Int 2008;39:777-81.  Back to cited text no. 14
15.Cudney N, Persico J, Cordell KG, D'Silva NJ. Adenomatoid odontogenic tumor developing in association with an odontoma: Report of a case. Quintessence Int 2008;39:693-7.  Back to cited text no. 15
16.Martínez A, Mosqueda-Taylor A, Marchesani FJ, Brethauer U, Spencer ML. Adenomatoid odontogenic tumor concomitant with cystic complex odontoma: Case report. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;108:e25-9.  Back to cited text no. 16
17.Phillips MD, Closmann JJ, Baus MR, Torske KR, Williams SB. Hybrid odontogenic tumor with features of ameloblastic fibro-odontoma, calcifying odontogenic cyst, and adenomatoid odontogenic tumor: A case report and review of the literature. J Oral Maxillofac Surg 2010;68:470-4.  Back to cited text no. 17
18.Soares EC, Costa FW, Neto IC, Bezerra TP, do Socorro Vidal Patrocínio RM, Alves AP. Rare hybrid odontogenic tumor in a 2-year-old child. J Craniofac Surg 2011;22:554-8.  Back to cited text no. 18
19.Prakash AR, Reddy PS, Rajanikanth, Bavle RM. Concomitant occurrence of cemento-ossifying fibroma and adenomatoid odontogenic tumor with bilateral impacted permanent canines in the mandible. Indian J Dent Res 2012;23:434-5.  Back to cited text no. 19
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20.Agarwal A, Giri KY, Alam S. The interrelationship of adenomatoid odontogenic tumour and dentigerous cyst: A report of a rare case and review of the literature. Case Rep Pathol 2012;2012:358609.  Back to cited text no. 20
21.Laheji A, Sakharde S, Chidambaram S, Gondhalekar RR, Shankar U, Radhika A. Adenoameloblastoma: A dilemma in diagnosis. J Contemp Dent Pract 2012;13:925-9.  Back to cited text no. 21
22.Li BB, Xie XY, Jia SN. Adenomatoid odontogenic tumor with fibro-osseous reaction in the surrounding tissue. J Craniofac Surg 2013;24:e100-1.  Back to cited text no. 22
23.Mutalik VS, Shreshtha A, Mutalik SS, Radhakrishnan R. Adenomatoid odontogenic tumor: A unique report with histological diversity. J Oral Maxillofac Pathol 2012;16:118-21.  Back to cited text no. 23
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Correspondence Address:
Samapika Routray
Department of Oral Pathology & Microbiology, Institute of Dental Sciences, SOA University, Sector-8, Kalinga Nagar, Ghatikia, Bhubaneswar - 751 003, Odisha
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0377-4929.134721

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  [Figure 1], [Figure 2], [Figure 3], [Figure 4]

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