International Journal of Otorhinolaryngology and Head and Neck Surgery Soorya Rao R et al. Int J Otorhinolaryngol Head Neck Surg. 2017 Jan;3(1):140-143 http://www.ijorl.com pISSN 2454-5929 | eISSN 2454-5937
DOI: http://dx.doi.org/10.18203/issn.2454-5929.ijohns20164818
Case Report
Adenomatoid odontogenic tumour in the maxilla: a rare benign tumour
in an uncommon site
Soorya Rao R.*, Ravi K. S.
Department of Otorhinolaryngology and Head and Neck Surgery, Adichunchanagiri Institute of Medical Sciences BG nagara. Bellur cross, Nagamangala Taluk, Mandya District, Karnataka, India Received: 19 November 2016 Accepted: 24 December 2016 *Correspondence: Dr. Soorya Rao R, E-mail: sooryarao14@gmail.com Copyright: © the author(s), publisher and licensee Medip Academy. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT We report a case of adenomatoid odontogenic tumor (AOT) in the maxilla in a boy aged 17 years. AOT is an odontogenic tumour arising from the enamel or dental lamina. AOT is rare and it represents 3–7% of all odontogenic tumors. This lesion affects young girls and is associated with an impacted tooth, usually canine. This case is presented to highlight the presentation of the tumour in a male patient and in an uncommon site, the left upper 1st molar. Differentiating this benign tumor from other lesions is difficult before surgical management and histopathological examination is important in accurate diagnosis. Keywords: Adenomatoid odontogenic tumor, 1st molar, Follicular type
INTRODUCTION
Adenomatoid odontogenic tumour (AOT) is a rare benign neoplasm of odontogenic epithelial origin. Philipsen and Birn proposed the name Adenomatoid odontogenic tumor, a term that was adopted by the first edition of the World Health Organization classification of odontogenic tumors in 1971.1,2 It is a relatively uncommon, benign and slow growing tumour.3 AOT accounts for 3-7% of all the odontogenic tumours.4 It is usually found in young patients, especially in the second decade of life.5 Females are more often affected than males. AOT commonly occurs in the maxilla especially in the anterior part of the jaw than the posterior part.2 The current WHO classification of odontogenic tumors defines AOT as being composed of odontogenic epithelium in a variety of histo-architectural patterns, embedded in a mature connective tissue stroma and characterized by slow but progressive growth.1 Adenomatoid odontogenic tumor can be associated with an impacted tooth. The origin of the tumour remains controversial but according to the
envelopmental theory they originate from the odontogenic epithelium of a dentigerous cyst.6
CASE REPORT
A 17 year old boy presented with a painless swelling on the left side of face for the last 6 months which was progressively increasing in size for the past 2 months. There was no history of trauma, pain or discharge from the lesion. He also had complaints of ipsilateral and persistent nasal obstruction for 2 months.
The swelling was of size 4 × 3 cm, on the left infra orbital and malar region and was hard in consistency. The swelling extended from the lower part of left naso-labial fold to middle of zygomatic arch horizontally and from the inferior orbital margin to the level of line of nares vertically. The mass had elevated the dorsum of the nose and medialised the lateral wall on the ipsilateral side leading to nasal obstruction. The swelling was hard and smooth with no local rise of temperature. It was not
International Journal of Otorhinolaryngology and Head and Neck Surgery | January-March 2017 | Vol 3 | Issue 1 Page 140
Soorya Rao R et al. Int J Otorhinolaryngol Head Neck Surg. 2017 Jan;3(1):140-143
tender. Skin over the swelling was normal and pinchable with no punctums or scars. The margins of the swelling were ill defined. Examination of the oral cavity showed no abnormalities.
Figure 1: Preoperative picture of the patient.
Figure 2: CT scan showing radiolucent lesion.
Figure 3: Operative procedure. a) Caldwell Luc incision b) mucoperiostel flap elevation c) infraorbital nerve ide d) anterior wall of maxillary sinus opened e)
releasing attachment on all sides f) cyst curetted out
Radiography showed a unilocular cystic, mass in the left superior alveolar margin encroaching the maxillary sinus with an unerupted 1st molar tooth within. The margins were well defined and osteosclerotic. A 3.7 × 2.5 cm sized radiolucent lesion containing a tooth within noted arising from the left anterolateral superior alveolar margin encroaching into the left maxillary sinus. There was resultant mass effect over the left nasal cavity with partial obliteration of anterior naris and anterior part of inferior meatus and soft tissue bulge caused by the lesion in the left maxillary region.
The surgical treatment given was enucleation of the cyst and curettage under general anaesthesia through a Caldwell Luc approach. The cyst was removed in toto from the maxillary sinus along with the teeth within.
The gross specimen was a single globular tissue mass of size 4×3×1.5 cm. It was grey brown in colour and a tooth was seen embedded in the soft tissue mass. The cut section showed firm solid areas in between.
Figure 4: Cut section of the specimen.
Histopathological examination showed a well circumscribed benign epithelial tumor with strands, sheets, whorls & ductular patterns around ductular lumina and tumor cells which were round to oval with scanty cytoplasm, uniform nuclei and bland chromatin. Epithelial tumor cells surrounded by polyhedral to spindle shaped cells, scattered homogenous hyaline material and calcified deposits, congested blood vessels & areas of stromal hemorrhage were seen confirming the diagnosis of adenomatoid odontogenic tumour. The follow-up examination after one year revealed no local recurrence.
Figure 5: Histopathological examination. a) circumscribed tumour, b) cells in ductular pattern,
c) Scant cytoplasm, bland chromatin.
after removal of cyst g) cavity h) gross specimen.
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Soorya Rao R et al. Int J Otorhinolaryngol Head Neck Surg. 2017 Jan;3(1):140-143
Figure 6: Postoperative photograph. DISCUSSION
The AOT is a benign non-invasive rare odontogenic tumour, showing slow growth which causes jaw swelling.12 There is a slight female over male predilection which is almost 2:1 and it appears most often in the second decade of life.13 WHO has described the histo- logic features of the tumour as follows, “a tumor of odontogenic epithelium with duct like structures and with varying degree of inductive changes 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 is generally believed that the lesion is not a neoplasm.”14,15
Our patient presented in the second decade of his life which is very characteristic of this tumour. The tumors are usually unilocular and 1.5 to 3 cm in size, but larger multilocular lesions has been reported.6 It is debatably thought to be a hamartoma or benign neoplasm. It is seen twice more commonly in maxilla7 than mandible and 40% are related to the crowns of unerupted maxillary canine teeth. In our case the patient was a male and impacted tooth was an upper molar which is rare.
AOT can occur as intraosseous and peripheral forms. Intraosseous AOT may be radiographically divided into 2 types- follicular (pericoronal) and extrafollicular (extracoronal) types.8 This type is usually discovered during routine radiographic examination.5 The extra- osseous (peripheral/gingival) type of AOT is rarely detected radiographically, but there may be slight erosion of the underlying alveolar bone cortex.2,8
The tumour here, presented as intraosseous, follicular type lesion which is the commonest type characterised by tumor manifests as a well-defined unilocular radiolucency surrounding the crown and partly the root of an unerupted tooth.
The clinical features and radiological findings are more or less the same for different slow lesions affecting the area. A differential diagnosis of dentigerous cyst, odontogenic keratocyst, ameloblastoma, odontogenic myxoma was considered. The cut section can be used to
assess the contents. It is mucoid in myxomas, paste like in odontogenic keratocyst and dentine in odontomas. In this case, differentiation is mainly based on histology especially the nature of epithelium.
The most striking pattern is various sizes of solid nodules of columnar or cuboidal epithelial cells forming nests or rosette-like structures with minimal stromal connective tissue. Between these characteristic eosinophilic amorphous material is found. Within the cellular areas tubular or duct-like appearance, nodules of polyhedral, eosinophilic epithelial cells with squamous appearances, pools of amorphous amyloid-like material and masses of calcified material are also seen.
Immunohistochemical studies of the lesion suggest expression of keratin and vimentin in the tumour cells at the periphery of the ductal, tubular or whorled structures.9,10 This type is often mistaken clinically as dentigerous cyst or odontogenic keratocyst because of the predominant cystic appearance here.11 Conservative surgical treatment is enucleation and curettage. It is curative and recurrence even after incomplete removal is rare.
CONCLUSION
Adenomatoid odontogenic tumour (AOT) is a benign odontogenic jaw lesion. The occurence of tumour in male patient from the upper first molar is noted. CT scan is mandatory for the diagnosis of such lesions which can easily be mistaken for a dentigerous cyst or odontogenic keratocyst. Definitive diagnosis is mostly postoperative after histopathological diagnosis. The treatment given in this case, enucleation and curettage is satisfactory and recurrence is rare.
Funding: No funding sources Conflict of interest: None declared Ethical approval: Not required
REFERENCES
1. Philipsen HP, Reichart PA, Siar CH, Ng KH, Lau SH, Zhang X. An updated clinical and epidemiological profile of the Adenomatoid odontogenic tumour: a collaborative retrospective study. J Oral Pathol Med. 2007;36:383-93. 2. Swasdison S, Dhanuthai K, Jainkittivong A, Philipsen HP. Adenomatoidodontogenic tumors: an analysis of 67 cases in a Thai population. OOOOE. 2008;105:210-5. 3. Toida M, Hyodo I, Okuda T, Tatematsu N. Adenomatoid Odontogenic Tumor: report of two cases and survey of 126 cases in Japan. J Oral Maxillofacial Surgery. 1990;48:404–8. 4. White SC, Phaorah MJ. Principles and Interpretation. 5th edition. St Louis: Mosby; 2004: 431–433.
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5. Shetty K, Vastardis S, GianniniP. Management of an unusually large adenomatoid odontogenic tumor. Oral Oncology Extra. 2005;41:316–8. 6. Philipsen HP, Samman N, Ormiston IW, Wu PC, Reichart PA. Variants of the adenomatoid odontogenic tumor with a note on tumor origin. J Oral Pathol Med. 1992;21:348–52. 7. Nonaka CF, de Souza LB, Quinderé LB. Adenomatoid odontogenic tumour associated with dentigerous cyst--unusual case report. Rev Bras Otorrinolaringol (Engl Ed). 2007;73(1):129–31. 8. Philipsen HP, Reichart PA. Adenomatoid odontogenic tumour: facts and figures. OralOncol. 1998;35:125–31. 9. Praveen Kumar M, Ranganathan T. Adenomatoid odontogenic tumor associated with calcifying epithelial odontogenic tumor. Int J Oral Max Sur. 1986;15(4):469-73. 10. Tatemoto Y, Tanaka T, Okada Y, Mori M. Adenomatoid odontogenictumor: co-expression of keratin and vimentin. Virchows Arch A Pathol Anat Histopathol. 1988;413(4):341–7.
11. Vasconcelos BC, Frota R, Cardoso AB, Porto GG, Carneiro SC. Adenomatoid-odontogenic tumor. Braz J Otorhinolaryngol. 2008;74(2):315. 12. Nigam S, Gupta SK, Chaturvedi KU. Adenomatoid odontogenic tumor - A rare cause of jaw swelling. Braz Dent J. 2005;16:251–3. 13. Ajagbe HA, Daramola JO, Junaid TA, Ajagbe AO. Adenomatoid odontogenic tumor in a black African population: report of thirteen cases. J Oral Maxillo fac Surg. 1985;43:683–7. 14. Rashmi G, Santosh G, Harshavardhan S, Praveen KM. Adenomatoid odontogenic tumor. Indian J Dental Advan. 2009;1(1):67-72. 15. Kramer, Ivor R.H, Pindborg JJ, Shear M. WHO international histological classification of tumours. Histology typing of odontogenic tumor. 2nd ed. Berlin: springer vering; 1992.
Cite this article as: Soorya Rao R, Ravi KS. Adenomatoid odontogenic tumour in the maxilla: a rare benign tumour in an uncommon site. Int J Otorhinolaryngol Head Neck Surg 2017;3:140-3.
International Journal of Otorhinolaryngology and Head and Neck Surgery | January-March 2017 | Vol 3 | Issue 1 Page 143