Annals of African Medicine

: 2015  |  Volume : 14  |  Issue : 1  |  Page : 65--68

Acanthomatous ameloblastoma of mandible crossing the midline: A rare case report

Neha Bansal1, Soheyl Sheikh2, Richa Bansal3, Robin Sabharwal4, Aanchal Gupta5, Ankit Goyal5, Nitika Kainth6,  
1 Departments of Oral Medicine and Radiology, Surendera Dental College and Research Institute, Sri Ganganagar, Rajasthan, India
2 MM College of Dental Sciences and Research, Mullana, Ambala, Haryana, India
3 Departments of Oral Pathology and Microbiology, Seema Dental College and Research Institute, Rishikesh, Uttarakhand, India
4 Bhojia Dental College and Hospital, Baddi, Himachal Pradesh, India
5 Department of Oral Medicine and Radiology, Kalka Dental College and Hospital, Meerut, India
6 Private Practitioner, Max Hospital, Noida, Uttar Pradesh, India

Correspondence Address:
Robin Sabharwal
Department of Oral Pathology and Microbiology, Bhojia Dental College and Hospital, Baddi, Himachal Pradesh


Ameloblastoma is the most common aggressive benign odontogenic tumor of the jaws. Ameloblastoma is a benign epithelial odontogenic tumor that typically arises in the mandible or maxilla or, rarely, in the immediate adjacent soft tissues. A clinical, radiographic and histopathological report is presented of a case of acanthomatous ameloblastoma in relation to molar in the left mandible of a 30-year-old healthy male. The histopathological examination of the removed specimen revealed the histopathological pattern of an acanthomatous ameloblastoma. The radiographic appearance of the lesion showed the presence of multilocular radiolucencies, which were crossing the midline, which is rarely found in ameloblastoma. Due to its rarity and lack of data, we take this opportunity to present a world first case of acanthomatous ameloblastoma which was crossing the midline.

How to cite this article:
Bansal N, Sheikh S, Bansal R, Sabharwal R, Gupta A, Goyal A, Kainth N. Acanthomatous ameloblastoma of mandible crossing the midline: A rare case report.Ann Afr Med 2015;14:65-68

How to cite this URL:
Bansal N, Sheikh S, Bansal R, Sabharwal R, Gupta A, Goyal A, Kainth N. Acanthomatous ameloblastoma of mandible crossing the midline: A rare case report. Ann Afr Med [serial online] 2015 [cited 2020 Sep 27 ];14:65-68
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Ameloblastoma is a benign epithelial odontogenic tumor that typically arises in the mandible or maxilla or, rarely, in the immediate adjacent soft tissues. [1] It arises from dental embryonic remnants possibly from the epithelial lining of an odontogenic cyst; dental lamina or enamel organ; stratified squamous epithelium of the oral cavity; or displaced epithelial remnants. [2] Ameloblastoma is reported to constitute about 1-3% of tumors and cysts of the jaws. [1] The peak incidence occurs in the third and fourth decades of life, they are uncommon in the second decade and exceedingly rare in children under the age of 10. [3] The vast majority of ameloblastomas occur in the posterior mandible (80-85%) with the remainder of tumors presenting in the maxilla. Histologically, ameloblastoma is of six types-follicular, plexiform, granular, basal, desmoplastic and acanthomatous. [4] Ameloblastoma is a locally destructive tumor with a propensity for recurrence if not entirely excised.

We report a rare case of acanthomatous ameloblastoma occurring in the left posterior mandible and crossing the midline involving the right side of jaw. It is of concern that this acanthomatous ameloblastoma crossing the midline, which is rarest entity and never found as a lesion in human but it was seen in the case report of dogs as a canine acanthomatous ameloblastoma.

 Case Report

The present case report is about a 30-year-old male patient, a shop keeper by profession presented to the Department of Oral Medicine and Radiology with a chief complaint of painless, gradually progressive swelling in the left posterior side of mandible for 6 months. The present history revealed that the swelling was slowly growing over a period of 6 months and was not associated with pain, tenderness or discharge. The swelling was associated with numbness of lower lip.

Intraoral examination showed a well-circumscribed swelling on both buccal and lingual aspect, extending from lower mesial of second premolar to distal second molar, obliterating both labial and lingual sulcus [Figure 1]. On palpation, the swelling was bony hard, nonpulsatile, noncompressible and nontender in nature. No lymphadenopathy or fistulae were present. Past history and medical history were unremarkable and nonsignificant.{Figure 1}

On radiographic investigations, intraoral periapical radiograph revealed multilocular radiolucencies in region of 35, 36, 37 [Figure 2]. A series of intraoral periapical radiographs with respect to 31, 32, 33, 34, 35, 36, 37, 38, 41, 42, 43 were made and that revealed multilocular radiolucencies extending and crossing the midline [Figure 3]. Significant root resorption was seen in relation to 31, 32, 33 and 34. Further investigations were carried out, which included panoramic radiography and noncontrast computed tomography (CT).{Figure 2}{Figure 3}

Panoramic radiograph revealed multilocular radiolucencies extending from the region of 37 to 42. However, the lower border of mandible was spared [Figure 4]. Occlusal radiograph revealed typical soap bubble appearance along with buccal and lingual plate expansion. CT scan revealed lobulated, predominantly lytic, expansile, multiloculated lesion involving the mandibular alveolus on the left side in relation to lower left incisors, canine and premolar reaching up to symphysis and causing widening of mandibular alveolus with thinning and erosion of both buccal and lingual surfaces. The lesion was seen extending up to adjacent soft tissue on buccal surface [Figure 5] and [Figure 6].{Figure 4}{Figure 5}{Figure 6}

On aspiration, straw colored fluid was extracted which was inconclusive of diagnosis. Hence the patient was sent for incisional biopsy since the growth was of larger size. The histopathological examination revealed numerous follicles of tumor cells in connective tissue stroma. At the periphery, follicle was lined by single layer of tall columnar ameloblast like cells with reverse polarity. In center island showed loosely arranged polygonal or angular cells resembling stellate reticulum. Many follicles showed squamous metaplasia. Some follicle showed cystic degeneration of central stellate reticulum like cells.

Thus, on clinical, radiographical and histopathological findings, final diagnosis was given of acanthomatous ameloblastoma and the patient was sent to Department of Oral and Maxillofacial Surgery for complete excision. An informed and written consent about anesthesia and surgical procedure was obtained. Patient was operated general anesthesia and hemimandibulactomy was carried out leaving sufficient margins [Figure 6]. All involved teeth were removed along with the lesion[Figure 7]. Post operative OPG was done [Figure 8]{Figure 7}{Figure 8}


Ameloblastoma is a benign epithelial odontogenic tumor but is often aggressive and destructive, with the capacity to attain great size, erode bone and invade adjacent structures. Although the term ameloblastoma was coined by Churchill in 1933, the first detailed description of this lesion was by Falkson in 1879. [5],[6] It is the most common odontogenic tumor although it represents only about 1% of tumors and cysts of the jaws and 11% of the odontogenic tumors. In the mandible (80% of ameloblastomas), 70% are located in the area of the molars or the ascending ramus, 20% in the premolar region and 10% in the anterior region. [7],[8],[9],[10] On an average 10-15% of ameloblastomas are associated with a nonerupted tooth. The study by Adebiyi et al. reported that most of the solid lesions belonged to the follicular type (70.4%), plexiform (14.1%) and acanthomatous (4.2%). [11]

In this case, acanthomatous type of ameloblastoma found in the molar region of the mandible and it was not associated with a nonerupted tooth.

Ameloblastoma appears equal frequency between sexes, although a higher frequency in females than in males has been described. [5],[6] Acanthomatous ameloblastoma mostly occurs in older patients rather than younger ones. The mean age of occurrence (±standard deviation) was 61.3 ± 1.2 range 60-62 years with a peak incidence in the 7 th decade of life. [8] However, in our case, the patient was male and was in third decade of his life. [11]

The acanthomatous ameloblastoma exhibits varying degrees of squamous metaplasia and even keratinization of the stellate reticulum portion of the tumor islands; however, peripheral palisading is maintained and no cytologic features of malignancy are found. The so-called kerato-ameloblastoma is a rare variant of ameloblastoma that contains prominent keratinizing cysts that may cause some alarm and distract the pathologist from the otherwise ameloblastomatous feature. [2]

"Radiographically, ameloblastoma shows a typical soap bubble" appearance when the radiolucent loculations are large and as being "honeycombed" when the lobulations area small. In our case study, the radiographic appearance of the lesion was consistent with that of an ameloblastoma except for the presence of multilocular radiolucencies extending and spreading widely crossing the midline, which is rarely found in ameloblastoma.

Clinically, ameloblastomic carcinomas are more aggressive than most typical ameloblastomas. Perforation of the cortical plate, extension into surrounding soft tissue, numerous recurrent lesions and metastasis, usually to cervical lymph nodes, can be associated with ameloblastic carcinomas and hence it should be considered as the differential diagnosis. [12]


The present case has some interesting findings distinguished it from other reported cases of ameloblastoma. First, this is a case of acanthomatous ameloblastoma which is an extremely rare variant. Second, radiographically seen the lesion is crossing the midline which is never been in literature. Third, the size of the lesion is extremely small. Finally, it is usually found in the age of old age years, but in this case, the age was only 30 years.


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