ONLINE ONLY - CASE REPORT
|Year : 2022 | Volume
| Issue : 2 | Page : 291
An unusual case report of basal cell ameloblastoma and a detailed review of literature
Kirti Buva1, Ajinkya Deshmukh2, Pratibha Kavle1, Anish Gupta3
1 Oral Pathology and Microbiology, Bharati Vidyapeeth (Deemed to be University) Pune, Navi Mumbai, Maharashtra, India
2 Oral Pathology and Microbiology, Preclinical Research Centre, Navi Mumbai, Maharashtra, India
3 People's Dental Academy, People's University Bhopal, Madhya Pradesh, India
|Date of Submission||20-Feb-2022|
|Date of Decision||24-Apr-2022|
|Date of Acceptance||09-May-2022|
|Date of Web Publication||28-Jun-2022|
Bharti Vidyapeeth Deemed to be University Dental College and Hospital, Navi Mumbai, Maharashtra
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Ameloblastoma is an odontogenic tumour derived from the remnants of odontogenic epithelium. Ameloblastoma shows versatile clinical and histological variants. Basal cell ameloblastoma is a rare variant among all histopathological variants of ameloblastoma. We present a case of a 25-year-old male patient with painless swelling on the lower left side of the face for 1 year, which had gradually increased in size and histologically showed features of basal cell ameloblastoma. The aim of the present paper is to understand this rare variant of ameloblastoma and review the literature.
Keywords: Ameloblastoma, basal cell variant, odontogenic tumor
|How to cite this article:|
Buva K, Deshmukh A, Kavle P, Gupta A. An unusual case report of basal cell ameloblastoma and a detailed review of literature. J Oral Maxillofac Pathol 2022;26:291
|How to cite this URL:|
Buva K, Deshmukh A, Kavle P, Gupta A. An unusual case report of basal cell ameloblastoma and a detailed review of literature. J Oral Maxillofac Pathol [serial online] 2022 [cited 2022 Aug 12];26:291. Available from: https://www.jomfp.in/text.asp?2022/26/2/291/348766
| Introduction|| |
Ameloblastoma is stated to be the second most common locally aggressive tumour among all odontogenic tumors. They may arise from odontogenic epithelium like cell rest of Malassez or cell rests of Serre, heterotopic epithelium in the pituitary gland, odontogenic cysts such as dentigerous cyst, odontomas and basal cells of the surface epithelium of the jaws. Ameloblastoma comprises 2%–3% of all pathologies of the jaw. Ameloblastoma most commonly occurs in the mandible than the maxilla, the ratio being 5:1. The average age of occurrence reported is about 38.9 years.
In the recent classification of the World Health Organization (WHO) 2017, ameloblastoma has been classified clinically as conventional, unicystic and peripheral variant, whereas histopathologically under conventional, it has been further classified as follicular and plexiform (being most common) and others (granular, basal cell variant, acanthomatous, clear cell variant etc.) To avoid any misperception, 'solid or multicystic amelobalstoma' term has been omitted as it was confused with unicystic. The desmoplastic variant is considered only a histopathologic variant than a clinical entity. Granular cell ameloblastoma, clear cell variant of ameloblastoma and basal cell variant of ameloblastoma are considered rare variants. Moreover, as the basal cell variant of ameloblstoma is an odontogenic variant (benign), it may share a similar pathological picture as basal cell carcinoma (BCC) or basaloid squamous cell carcinoma (BSCC) (malignant). As published data on basal cell variant of ameloblastoma is scarce, it is difficult to understand certain molecular pathology and diagnosis. In the present paper, we present the basal cell variant – a rare histopathological variant of ameloblastoma along with a detailed review of the literature.
| Case Report|| |
A 25-year-old male patient with a complaint of swelling in the left posterior part of the mandible for the last 1 year was referred by a surgeon. There was no relevant medical, dental, family or habit history of the patient. Extraoral findings were remarkable, and facial asymmetry was evident. The overlying skin was normal, and no signs of trauma or pus discharge were seen. Clinical examination suggested non-mobile, non-fluctuant diffuse and hard swelling extending from the inner canthus of the eye to the lower border of the mandible. [Figure 1] and [Figure 2] Intraorally, the buccal sulcus was obliterated. Radiographical findings seen in an orthopantomography were suggestive of diffuse radiolucency involving the body of the mandible and angle of the mandible, thinning of the inferior border of the mandible was seen, and the right-side mandible was normal. [Figure 3] Computed tomography showed expansion of cortical plates with well-demarcated borders. The medial and lateral borders showed homogenous density throughout. [Figure 4]. The provisional diagnosis was an odontogenic tumor or odontogenic keratocyst. An incisional biopsy was taken, and hematoxylin and eosin–stained section was reported as ameloblatoma by a general pathologist.
|Figure 1: Clinical photograph showing diffuse swelling at the left posterior mandible from the inner canthus of the eye involving the inferior border of the mandible. (Anterior View)|
Click here to view
|Figure 2: Clinical photograph showing diffuse swelling at the left posterior mandible from the inner canthus of the eye involving the inferior border of the mandible. (Inferior view)|
Click here to view
|Figure 3: Orthopantomography showing diffuse radiolucency involving the body of the mandible and angle of the mandible, thinning of the inferior border of the mandible.|
Click here to view
|Figure 4: Computed tomography showing an expansion of cortical plates with well-demarcated borders. The medial and lateral borders show throughout homogenous density.|
Click here to view
Under general anesthesia, the patient underwent a partial mandibulectomy extending from the premolar region to the neck of the mandible. The excisional tissue was referred for histopathological reporting. The excisional biopsy report was the same as the provisional diagnosis. The slide was referred to a private laboratory for a second opinion where we received hematoxylin and eosin–stained slide. The slide showed numerous follicles and islands containing basaloid cells in mature fibrous connective tissue stroma. At the periphery of the follicles, cuboidal to tall columnar cells were seen with hyperchromatic nuclei, and no reverse polarity of nuclei was seen. Cells in the center were basaloid. There was a lack of stellate reticulum-like cells in the center. Few cystic spaces were evident in the follicles. Overall, the picture was suggestive of the basal cell ameloblastoma. [Figure 5], [Figure 6] and [Figure 7] The patient was followed up for 1 and 1/2 years, and there was no recurrence.
|Figure 6: 10 × view showing basaloid cells in a follicle lacking reverse polarity of nuclei. The centre of the follicle is filled with hyperchromatic basaloid cells lacking stellate reticulum-like cells in the center.|
Click here to view
| Discussion|| |
Ameloblastoma was known as 'Admantinoma', the term 'Ameloblastoma' was coined by Churchill in 1933. It is a benign odontogenic tumor arising from odontogenic epithelium which is aggressive in nature. The first detailed report published was by Falkson 1879. Literature suggests that about 80% of ameloblastoma cases are seen in the mandible and 20% in the maxilla. Basal cell variant of ameloblastoma is also more commonly seen in the mandible. Most cases reported are in the 4th decade. Various hybrid variants of ameloblastoma are reported in the literature. Basal cell ameloblastoma (BCA) is the rarest, it comprises only 2% of all histopathological variants of conventional ameloblastoma with only 28 cases reported till date. Hence, it is difficult to understand nature and clinicopathological relation. We did a PubMed and google scholar database search for basal cell variant of ameloblastoma [Table 1].,,,,,,,,,,,,,,, We found that most of the reported cases of BCA were seen in the 3rd to 5th decade, and the maxilla to mandible ratio reported was 1:1.2 with no gender predilection.
|Table 1: Reported cases of basal cell variant of ameloblastoma with age, gender and location details|
Click here to view
Histopathologically, the tumour essentially consists of follicles and strands of basaloid cells. Cells at the periphery show hyperchromatic nuclei. The central cells of the islands or follicles are devoid of stellate reticulum-like cells and instead show basaloid cells only. These features were evident in our case too. [Figure 7] There is no columnar cell layer and palisading nuclei like other variants of ameloblastoma. Some cases might show cystic degeneration. Alterations in the peripheral cell nuclei can be seen., Histopathologically, differential diagnosis can be intraoral basal cell carcinoma and basal cell adenoma., Immunohistological (IHC) studies have been conducted on variants of ameloblastoma including six cases of BCA. Cytokines were consistent with all variants of ameloblastoma, but an elevation of p53 and ki-67 was evident in the basal cell variant. Two cases showed BRAF gene mutation. Further studies on histopathological and immunohistochemical features of basal cell ameloblastoma are needed to understand its resemblance with basal cell carcinoma (BCC), as one is benign, and another is malignant with a concern of metastasis. Jawad and Abdullah conducted a study on basal cell variant of ameloblastoma and basal cell carcinoma using a panel of markers, and they found MMP-2 is higher in basal cell ameloblastoma whereas p53 and MMP-9 were increased in basal cell carcinoma. Due to the scarcity of data, the exact nature of BCA cannott be predicted.
Sandra et al. conducted a study using immunohistochemical (IHC) markers, monoclonal anti-proliferating cell nuclear antigen and Ki-67 in all variants of ameloblastoma, they stated that in BCA these two labeling indices were highest than that of other variants of Ameloblastoma. Sridhar et al. reported a case of BCA with a detailed review, they mentioned that it is needed to differentiate BCA, intraosseous adenoid cystic carcinoma, BCC and basal squamous cell carcinoma (BSCC). Hence, the expression of IHC markers in BCA are lack of CK7, CK8, CK10, CK18, CK20, EMA and positivity for MNF116, AE1/AE3, KL1,34, EL12.Whereas Ghattamaneni et al. stated that CK19, amelogenin or enamelin can be used for differentiating BCA, BCC, and BSCC. They used CK19 IHC marker and found that it shows a diffuse positivity in BCA. We searched for papers where IHC markers in BCA were studied. [Table 2],,,,,
|Table 2: Immunohistochemical markers positive in Basal cell ameloblastoma|
Click here to view
Treatment modalities of BCA are controversial due to the nature of ameloblastoma, which is benign but still aggressive. Enucleation, curettage, cautery, laser, chemotherapy, radiotherapy, and marginal, composite sectional resection are considered conservative treatment modalities. Curettage and enucleation show the highest recurrence rates that is 55%–90%. Radical resections having 1 cm resected margins show 0%–15% recurrence rate and is considered the best modality till date. Exclusive treatment modalities for the basal cell variant are no different than conventional; however, the prognosis may be controversial due to the lack of reported cases.
| Conclusion|| |
Basal cell ameloblastoma is a rare variant of ameloblastoma. Its histopathological picture resembles basal cell carcinoma. Hence, the diagnosis must be given considering clinical, radiographical, histopathological and by using IHC markers. In the present paper, we have tried to explain this rare entity with its review of the literature. This is an endeavour to report a case for a better understanding of its histopathological and immunohistochemical nature and treatment modalities.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Chae M, Smoll N, Hunter-Smith D, Rozen W. Establishing the natural history and growth rate of ameloblastoma with implications for management: Systematic review and meta-analysis. PLoS One 2015;10:e0117241.
Shakya H, Khare V, Pardhe N, Mathur E, Chouhan M. Basal cell ameloblastoma of mandible: A rare case report with review. Case Rep Dent 2013;2013:1-4.
Small I, Waldron C. Ameloblastomas of the jaws. Oral Surg Oral Med Oral Pathol 1955;8:281-97.
Cadavid A, Araujo J, Coutinho-Camillo C, Bologna S, Junior C, Lourenço S. Ameloblastomas: Current aspects of the new WHO classification in an analysis of 136 cases. Surg Exp Pathol 2019;2:17.
Rajendran R. Cyst andtumors of odontogenic origin. In: Rajendran R, Sivapathasundharam B, editors. Shafers Text Book of Oral Pathology. 7th
ed. New Delhi: Elsevier Publishers; 2012. p. 259-316.
Lucas RB. Pathology of Tumours of the Oral Tissues. 4th
ed. Edinburgh: Churchill Livingstone; 1984. p. 31-59.
Saify F, Sharma N. Basal cell ameloblastoma: A rare case report and review of literature. Oral Maxillofac Pathol J 2010;1:1-7.
Kaur M, Bhat N. Aggressive basal cell ameloblastoma: A rare diagnostic enigma. Int J Curr Adv Res 2020;9:21529-31
Kazakydasan S, Zamhari A, Achol L. Basal cell ameloblastoma in a paediatric patient: A case report and review of oral basal cell tumours. Oral Surg 2019;12:248-54.
Matsuo R, Fujiwara K, Ohyama S, Nakagawa H, Goto M, Katsuki T. Basal cell ameloblastoma of the maxilla. Japanese J Oral Maxillofacial Surg1988;34:2257-61.
Iordanidis S, Makos C, Dimitrakopoulos J, Kariki H. Ameloblastoma of the maxilla. Case report. Aust Dent J 1999;44:51-5.
Hirota M, Aoki S, Kawabe R, Fujita K. Desmoplastic ameloblastoma featuring basal cell ameloblastoma: A case report. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005;99:160-4.
Adebiyi KE, Ugboko VI, Omoniyi-Esan GO, Ndukwe KC, Oginni FO. Clinicopathological analysis of histological variants of ameloblastoma in a suburban Nigerian population. Head Face Med 2006;2:42.
Giraddi GB, Anusha AS. Basal cell ameloblastoma–review of literature with report of three cases. J Oral Biol Craniofac Res 2012;2:53-6.
Pendyala SK, Srinivasan B, Kondreddy K, Kumaresan R, Venkatachalapathi S. Basal cell ameloblastoma: Report of a rare case with review of literature. Indian J Mednodent Allied Sci 2014;2:75.
Kumar PS, Balamanikanda S, Kameswari K, Kumaresan R, Venkatachalapathi S. Basal cell ameloblastoma: Report of a rare case with review of literature. Indian J Mednodent Allied Sci 2014;2:759.
Sridhar M, Bhaskar Reddy L, Kharat S, Mahesh B, Gandi L, Mahendra A, et al
. Basal cell ameloblastoma: A rare histological variant of an uncommon tumor. Niger J Surg 2015;21:66.
] [Full text]
Virmani N, Dabholkar J. Giant multiloculated ameloblastoma of the mandible: A case report and review of literature. Int J Otorhinolaryngol Head Neck Surg 2016;2:91.
Ghattamaneni S, Nallamala S, Guttikonda V. Unicystic ameloblastoma in conjunction with peripheral ameloblastoma: A unique case report presenting with diverse histological patterns. J Oral Maxillofac Pathol 2017;21:267-72.
] [Full text]
Kosanwat T, Poomsawat S, Juengsomjit R. Ameloblastic carcinoma ex ameloblastoma of the maxilla. J Oral Maxillofac Pathol 2019;23:58-62.
] [Full text]
Lee ST, Udayakumar SI, Kwon TG, Shin HI, Choi SY. Ameloblastoma secondary to third molar extraction and sagittal split ramus osteotomy: A case report. Kor J Oral Maxillofac Pathol2018;42:39-43.
You Z, Sun L, Yan X, Zhang J, Du J, Li T, et al
. Clinicopathologic study on a rare variant of ameloblastoma with basal cell features. Oral Dis 2019;25:788-95.
Abrishami M, Mojafari P, Mirhashemi M, Moghaddam R, Abbaszadeh H. Combined keratocystic odontogenic tumor and basal cell ameloblastoma: A rare case report. J Maz Univ Med Sci 2021;31:188-93.
Kameyama Y, Takehana S, Mizohata M, Nonobe K, Hara M, Kawai T, et al
. A clinicopathological study of ameloblastomas. Int J Oral Maxillofac Surg 1987;16:706-12.
Bajpai M, Pardhe N. An Insight into the Histopathology of Oral Neoplasms with Basaloid Morphology and a Working Classification. Philipp J Pathol 2017;2:20-4.
Sandra F, Mitsuyasu T, Nakamura N, Shiratsuchi Y, Ohishi M. Immunohistochemical evaluation of PCNA and Ki-67 in ameloblastoma. Oral Oncol 2001;37:193-8.
Ghandhi D, Ayoub AF, Pogrel MA, MacDonald G, Brocklebank LM,
Moos KF. Ameloblastoma: A surgeon's dilemma. J Oral Maxillofac Surg 2006;64:1010-4.
Kreppel M, Zöller J. Ameloblastoma-clinical, radiological, and therapeutic findings. Oral Dis 2018;24:63-6.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]
[Table 1], [Table 2]