|Year : 2016 | Volume
| Issue : 1 | Page : 61-65
Acanthomatous ameloblastoma: A rare presentation
Ramaswamy Pachigolla, Raga Geethika Velugubantla, Sai Kiran Chennoju, Swathi Erva
Department of Oral Medicine and Radiology, St. Joseph Dental College, Eluru, Andhra Pradesh, India
|Date of Web Publication||8-Sep-2016|
Raga Geethika Velugubantla
St. Joseph Dental College, Eluru, Andhra Pradesh
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Ameloblastoma is the most frequent odontogenic tumor arising from dental epithelium. It is characterized by its histological resemblance to the enamel organ of the developing tooth germ; but enamel formation is not observed. Acanthomatous ameloblastoma is considered an aggressive odontogenic tumor characterized by irregular verrucous masses adjacent to the tooth, consisting of sheets of keratinizing odontogenic epithelium. Here we are reporting a case of 35-year-old male with swelling on left body of the mandible region which was diagnosed as acanthomatous ameloblastoma based on clinical, radiographic and histopathological features.
Keywords: Acanthomatous ameloblastoma, histopathological, keratinizing, odontogenic
|How to cite this article:|
Pachigolla R, Velugubantla RG, Chennoju SK, Erva S. Acanthomatous ameloblastoma: A rare presentation. J Indian Acad Oral Med Radiol 2016;28:61-5
|How to cite this URL:|
Pachigolla R, Velugubantla RG, Chennoju SK, Erva S. Acanthomatous ameloblastoma: A rare presentation. J Indian Acad Oral Med Radiol [serial online] 2016 [cited 2020 Jan 24];28:61-5. Available from: http://www.jiaomr.in/text.asp?2016/28/1/61/189993
| Introduction|| |
Ameloblastoma is a neoplasm of odontogenic epithelium, especially of enamel organ type tissue that has not undergone differentiation to the point of hard tissue formation. It has been postulated that the epithelium of origin is derived from one of the following sources: (1) cell rests of the enamel organ, (2) epithelium of odontogenic cysts, (3) disturbances of the developing enamel organ, (4) basal cells of the surface epithelium, or (5) heterotropic epithelium in other parts of the body. Ameloblastoma is classified according to WHO and the International Agency for Research on Cancer, 2003 as a benign tumor with odontogenic epithelium, mature fibrous stroma and without odontogenic ectomesenchyme. It is further classified into: Solid/multicystic, extraosseous/peripheral, desmoplastic and unicystic. The multicystic ameloblastoma has histological variants including follicular, plexiform, acanthomatous, granular cell, desmoplastic and basal cell types. Here, we are reporting a case of 35-year-old male patient with swelling on left body of the mandible region.
| Case Report|| |
A 35-year-old male patient reported with swelling over the left lower third of the face since 2 years. The swelling was initially small, gradual in onset and became aggressive in growth since 6 months. It was also associated with mild, intermittent pain that aggravated while eating and relieved on taking medication since 6 months. No secondary associated symptoms were noted. Two years back, he had undergone extraction in left posterior mandible region in relation to 37 and root canal treatment in relation to 36. Medical, family, and personal histories were non-contributing.
Extraoral examination revealed a single diffuse swelling of the left lower third of the face [Figure 1]. It was 5 × 2 cm in size, which extended from the right parasymphyseal region, crossing the midline to 2 cm in front of the left angle of mandible anteroposteriorly and 2 cm below the left ala–tragus line to the lower border of the mandible superoinferiorly. The edges appeared indistinct; skin over the swelling appeared tense and glossy, without any change in color. On palpation, the swelling was non-tender and firm to hard in consistency. No local rise in temperature was noted. Intraorally, single diffuse swelling was present that extended from distal side of 42 to distal side of 36, which was 5 × 2 cm in size [Figure 2]. Vestibular obliteration with lobulations was noted. Edges were indistinct. A missing lower left second molar tooth due to extraction was noted. On palpation, the swelling was non-tender and firm to hard in consistency. Based on the history and clinical features, a keratocystic odontogenic tumor was provisionally diagnosed. Ameloblastoma and central giant cell granuloma were considered as differential diagnoses.
Radiological investigations were performed and a mandibular occlusal radiograph revealed a large multilocular radiolucency mesial to left third molar with buccal cortical plate expansion. A well-defined increased radiolucency in the left premolar region and a multilocular radiolucency with honeycomb pattern present anteriorly were also observed [Figure 3]. Panoramic radiography showed a large multilocular radiolucency on the left side of the mandible, 0.5 cm mesial to the left third molar, extending anteriorly up to mesial side of right canine region. Coronal radiopacity involving enamel, dentine and pulp in relation to 36 was seen [Figure 4]. Axial and coronal CT of mandible showed osteolytic lesion that extended from distal side of 43 to mesial side of 38, crossing the midline. The internal structure showed a varying radiodensity comprising of hypodense area in the body of mandible and anteriorly hyperdense areas representing honeycomb pattern, which was surrounded by a buccal cortical bone [Figure 5] and [Figure 6].
|Figure 3: Occlusal radiograph showing multilocular radiolucency with honeycomb pattern anteriorly|
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|Figure 6: Coronal CT showing osteolytic lesion with honeycomb pattern anteriorly|
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The patient was subjected to surgery under general anesthesia. Lower lip split incision was performed [Figure 7]. Transmucosal incision was done from 36 to 43 region. Pathological site was exposed and the tumor was surgically enucleated along with curettage of the site including removal of 31, 32, 33, 34, 35, 36, 41, 42, 43 [Figure 8]. Bone wax was applied and hemostasis attained. Drain was placed and suturing was done layer by layer. Antibiotics, analgesics and anti-inflammatory drugs were given postoperatively.
The excised specimen was sent for histopathological examination [Figure 9]. Examination of hematoxylin and eosin stained sections showed islands of epithelium resembling enamel organ in a mature fibrous connective tissue stroma. The islands of epithelium were peripherally lined by a single layer of tall columnar ameloblast-like cells with reverse polarity. The central core of epithelial islands showed loosely arranged angular cells resembling stellate reticulum. Most of them showed squamous metaplasia associated with keratin formation. Few of the islands showed cells with nuclear pleomorphism and hyperchromatism with sheet-like proliferation of spindle cells [Figure 10]. Based on these findings, a final diagnosis of acanthomatous ameloblastoma was considered.
Wound healing was uneventful and the sutures were removed on the 7th postoperative day. Patient was reviewed after 6 months for clinical and radiographic assessment. During follow-up, there were no signs of inflammation, infection or recurrence of the tumor clinically. Radiographically, there was a large radiolucent area in the surgical site representing a surgical scar [Figure 11].
| Discussion|| |
Ameloblastoma is the most frequent odontogenic tumor arising from dental epithelium. It is characterized by its histological resemblance to the enamel organ of the developing tooth germ; but enamel formation is not observed. Ameloblastoma accounts for about 1% of all tumors of the jaw mainly encountered during third to fifth decades of life. About 80% of all cases occur in mandible, of which 70% cases are seen in the ramus.
Ameloblastomas are defined as benign, locally invasive, clinically malignant, slow-growing tumors, rarely associated with paresthesia and pain. However, many lesions are detected incidentally on radiographic studies in asymptomatic patients., The potential sources for this tumor are the cell rests of the enamel organ (cell rests of Malassez and cell rests of Serres), epithelial odontogenic cysts (dentigerous cysts), basal cells of the surface epithelium of the jaws and heterotrophic epithelium in other parts of the body.
Literatures reveals that follicular ameloblastoma is the most prevalent histological variant (64.9%), followed by the plexiform (13.0%), desmoplastic (5.2%) and acanthomatous (3.9%) varieties. In acanthomatous ameloblastoma, the cells occupying the position of the stellate reticulum undergo squamous metaplasia and keratin formation within the island of tumor. Moreover, recurrent tumors are more aggressive and anaplastic than the primary tumor, and have a biological behavior similar to that of squamous cell carcinoma.
No single standard type of therapy can be advocated. Rather, each case should be judged on its own merits. The stronghold of treatment is surgery with wide resection. If possible, conservative treatment such as enucleation and curettage can be done. Many authors suggest removal of margins 1.5–2 cm beyond the radiological limit to eliminate all microcysts. The present case was treated conservatively by enucleation along with curettage. Many studies suggest that treatment is an important prognostic factor, implicating the cause for recurrence. Follow-up is essential as most recurrences present within the first 5 years; however, some have been observed more than 10 years after the initial treatment.
| Conclusion|| |
Ameloblastomas are uncommon benign odontogenic neoplasms that rarely become malignant. To conclude, the definitive diagnosis is based on its histopathological variants which cannot be distinguished clinically and appropriate treatment planning should be provided.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11]