Case Reports

Ameloblastoma: Cytopathologic profile of 12 cases and literature review ABSTRACT Background: Fine-needle aspiration cytology (FNAC) has been used as a diagnostic tool in evaluating suspected lesions. It shows a high diagnostic accuracy for diagnosing salivary gland lesions. Aim: The aim of this study was to highlight FNAC as an effective diagnostic tool in the presumptive diagnosis of ameloblastoma. Materials and Methods: A total of 12 cases of ameloblastoma sampled by FNAC retrieved from the archives of the Oral Pathology Department were retrospectively studied. The smears were alcohol-fixed and stained with hematoxylin and eosin. All the 12 cases of FNAC had subsequent corresponding surgical incisional biopsy or excision specimens. Results: Cytologically, seven cases were diagnosed as benign odontogenic tumor more in favor of ameloblastoma. All the 12 fine-needle aspiration cases were given a histopathologic work-up and diagnosed as ameloblastomas. Of these, the seven cytologically diagnosed benign odontogenic lesions were also confirmed to be ameloblastoma by both incisional biopsy as well as surgical excision. Conclusion: It was deduced from the above results that FNAC helps potentially in diagnosing ameloblastoma. Key words: Ameloblastoma; fine needle aspiration cytology; odontogenic tumors

Introduction Ameloblastoma is the most common epithelial odontogenic tumor, comprising 1% of tumors and cysts arising in the jaws.[1] Available literature on ameloblastoma of the jaw reports with an average age of patients is 36 years. In developing countries, ameloblastomas occur in younger patients. Men and women are equally affected. Women are 4 years younger than men when ameloblastomas first occur, and the tumors appear to be larger in females. Dominant clinical symptoms such as painless swelling and slow growth are noncharacteristic. The ratio of ameloblastoma of the mandible to the maxilla is Access this article online Quick Response Code Website: www.jcytol.org

DOI: 10.4103/0970-9371.145652

5:1. Ameloblastomas of the mandible occur 12 years earlier than the maxilla. Ameloblastomas occur most frequently in the molar region of the mandible. In Blacks, ameloblastomas occur more frequently in the anterior region of the jaws. Radiologically, 50% of the ameloblastomas appear as multilocular radiolucent lesions with a sharp delineation. Histologically, one-third is plexiform, one-third follicular; other variants such as acanthomatous ameloblastomas occur in older patients. Two percent of ameloblastomas are peripheral tumors. Unicystic ameloblastomas occurring in younger patients have been found in 6%. [2] Cystic ameloblastomas occur with a wide age range but at a slightly lower mean age than solid lesions. There is very strong predilection for the mandible, and there appears to be no gender difference. Lesions frequently become large, destructive, and multilocular.[3] Fine-needle aspiration biopsy (FNAB) is a technique in which a fine needle is introduced into a mass, cellular material is aspirated, and a cytological diagnosis is rendered. It separates reactive and inflammatory processes that do not require surgical intervention from neoplasia and benign from malignant tumors. FNAB lends

Vidyadevi Chandavarkar, K Uma1, Mithilesh Mishra, R Sangeetha1, Radhika Gupta2, Ritika Sharma Departments of Oral Pathology and 2Periodontology, School of Dental Sciences, Sharda University, Greater Noida, Uttar Pradesh, Department of Oral Pathology, KLE, Bengaluru, Karnataka, India

1

Address for correspondence: Dr. Vidyadevi Chandavarkar, Department of Oral Pathology, School of Dental Sciences, Sharda University, Greater Noida, Uttar Pradesh, India. E-mail: [email protected]

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itself to the diagnosis of palpable head and neck masses, in particular, those that persist following antibiotic treatment.[4] The prudent use of these techniques can be cost-effective and negate the need for more invasive diagnostic procedures. FNAB represents a cost-effective and rapid technique for the assessment of nodules and masses within the head and neck.[5] FNAB provides accurate diagnosis of most salivary gland lesions and contributes to conservative management in many patients with nonneoplastic conditions.[6] A survey of studies on fine needle aspiration cytology (FNAC) shows a high diagnostic accuracy for the lesions of salivary gland, thyroid, parathyroid, lymph node, skin, soft tissue, and bone. FNAC has rarely been used as a diagnostic tool in odontogenic tumors and cysts. A few reports of ameloblastoma and ameloblastic carcinoma diagnosed by FNAC have appeared in the literature. Saleh et al.[7] reported a relatively small series of FNAC of intraoral and oropharyngeal lesions, where a few ameloblastoma cases were accurately diagnosed. However, aspiration cytology studies of ameloblastoma are few and limited. In this study, we retrospectively reviewed 12 cases of ameloblastoma sampled by FNAC with particular attention to the cytological features of ameloblastoma, diagnostic accuracy and cytological-histological correlation.

Materials and Methods Our inclusion criteria were cases of ameloblastoma for which FNAC was done. Other odontogenic tumors were not included in the study. Twelve cases of intraosseous jaw swellings that were sampled by FNAC and were diagnosed as ameloblastoma on biopsy, during the period of 2003-2008 were retrieved from the archives of the Oral Pathology Department. The fine needle aspirations were performed by the head and neck surgeons with an on-site evaluation for adequacy by the pathologist. The aspirations were performed using 22-25 gauge needles connected to a 10 mL disposable plastic syringe. After localizing the mass, the aspiration needle was passed into the lesion. The smears were alcohol-fixed and stained with hematoxylin and eosin. Of the 12 fine-needle aspiration cases, all had subsequent corresponding surgical specimens, either an incisional biopsy or surgical resection specimen.

Results Cytologically, seven cases were diagnosed as benign odontogenic tumor more in favor of ameloblastoma. All the 12 fine needle aspiration cases were given a histopathologic work-up (incisional biopsy and surgical excision) and diagnosed as ameloblastomas. Of these, the seven cytologically diagnosed benign odontogenic lesions 162

were also confirmed to be ameloblastoma by both incisional biopsy as well as excision. The detailed cytomorphology of positive FNAC cases are enumerated in the table [Table 1]. The other five cases were false negative on cytopathological examination. There were eight men and four women with a male:female ratio of 2:1.They had wide age range from 8 to 62 years with an average age of 35. The posterior part of the mandible was the most common site of involvement (7 cases). Other sites included the anterior mandible, anterior maxilla and posterior maxilla.

Discussion Ameloblastoma is a tumor of odontogenic epithelium that occurs in the jaws.[8] Utilization of FNAC in the diagnosis of odontogenic tumors seems to have attracted little attention. Attention to the palisading arrangement of ameloblast like epithelial cells and digitated, stellate reticulum-like cells may lead to the diagnosis of ameloblastoma. Ameloblastomas can be aspirated easily, and the cytologic features may be sufficiently distinctive.[9] In this study, our goal was to investigate the ability of FNAC to diagnose accurately ameloblastomas, and to address the cytologic-histologic correlation. We identified 12 cases of ameloblastoma that underwent FNAC during the period of 2003-2008, from our archives. Overall, the cytologic diagnosis correlated with histologic findings with regards to ameloblastoma in 7 of 12 cases with accuracy of 58.3%. However according to Kaliamoorthy et al.[10] the sensitivity of FNAC in the diagnosis of ameloblastoma was found to be 86.6% and specificity was 100%. Table 1: Description of cytomorphology of positive FNAC cases Cases Cytomorphology Case 1 Cytological smears showed clusters of epithelial cells resembling odontogenic islands. The cells revealed palisading arrangement resembling ameloblast-like epithelial cells Case 2 Cytological smears showed tightly packed clusters of basaloid ameloblast-like epithelial cells. The cells were hyperchromatic and showed palisading arrangement Case 3 Cytological smears showed hypercellular epithelial cells present in clusters and few mesenchymal elements. The epithelial cells showed darkly stained polarized nucleus resembling ameloblast like cells Case 4 Cytological smears showed tightly packed groups of ameloblasts like epithelial cells Case 5 Cytological smears revealed clusters of ameloblasts-like epithelial cells and digitated stellate reticulum like cells Case 6 Cytopathology revealed groups of tightly packed palisaded epithelial cells resembling ameloblasts like cells. Few squamous cells were also seen Case 7 Cytopathology showed sheets of tightly packed epithelial cells showing peripheral palisading. Few mesenchymal elements were also seen FNAC: Fine needle aspiration cytology

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Chandavarkar, et al.: Cytologic profile of ameloblastoma

Figure 2: Cytological smears showing tightly packed clusters of basaloid epithelial cells (H and E, x200) Figure 1: Cytological smears showing cell clusters resembling odontogenic islands (palisading arrangement of ameloblast-like epithelial cells) (H and E, x200)

In our study, cytopathologically the positive cases showed clusters of epithelioid hyperchromatic cells resembling ameloblast-like cells [Figures 1 and 2] which were histologically confirmed as ameloblastoma. Correlating with the cytologic findings of three cases of histologically proven ameloblastoma of mandible, Radhika et al.[11] reported tightly packed clusters of basaloid epithelial cells with palisading. They also reported squamous differentiation in all cases but was marked in one case seen as larger cells with a central nucleus and abundant cytoplasm showing keratohyaline granules and whorls.Another study Mathew et al.[12] reported a distinct, two-cell population consisting of small, hyperchromatic, basaloid-type cells and scattered larger cells with more open chromatin. Occasional fragments of mesenchymal cells with more elongated nuclei and ample, clear cytoplasm were also noted. Malignant cases that metastasized showed a prominent cytologic pleomorphism, cellular crowding with molding and a high mitotic/karyorrhexis index. Two of our cases were recurrent cases, wherein fine-needle aspiration was performed, and FNAC results were positive. This suggests that in recurrence cases if fine needle aspiration results are positive then incisional biopsy can be avoided. In our study, there were no cases of ameloblastic carcinoma but there are few reported cases of cytology of recurrent ameloblastoma with malignant change.[12] FNAC smears were highly cellular and showed isolated, scattered cells, small groups of basaloid cells and polygonal squamous epithelial cells. Stellate and spindle-shaped cells were also seen in the background.[13] In our study, the five false negative cytological diagnosis may be due to low cellularity or non-representative sample of the actual lesion. It can also be technically difficult to obtain the “back-and-forth” motion in the lesion for ideal aspiration

sampling. This emphasizes the significance of correlating the cytological diagnosis with the clinical history, and if clinical suspicion exists after negative FNAC, further investigation should be carried out. Other studies had similar findings and suggested that false negative FNAC is most likely related to inadequate specimen or sampling error. FNAC of oral and oropharyngeal lesions was shown to be sensitive (93%) and specific (86%) in the study by Shah et al.[7] A review of reported series presented in 1994 found that the diagnostic sensitivity varied between 81% and 100%, specificity was 94-100% and accuracy of tumor typing were 61-80%. Most false negative diagnosis relate to cystic tumors. In summary, we have demonstrated with a relatively small series that FNAC of ameloblastoma is a valid method for the evaluation of these lesions. This technique is simple, inexpensive, convenient and comfortable to the patient, and above all, can offer a rapid and accurate diagnosis. Since sample size was small, statistical significance could not be obtained. Still, more studies have to be carried out with larger sample size.

Acknowledgment We are thankful to Dr. Kavita Rao, Head of Department, Oral Pathology, VS Dental College, Bengaluru for her valuable support and guidance during the course of the study.

REFERENCES 1.

2. 3.

Choudhury M, Dhar S, Bajaj P. Primary diagnosis of ameloblastoma by fine-needle aspiration: A report of two cases. Diagn Cytopathol 2000;23:414-6. Reichart PA, Philipsen HP, Sonner S. Ameloblastoma: Biological profile of 3677 cases. Eur J Cancer B Oral Oncol 1995;31B:86-99. Rosenstein T, Pogrel MA, Smith RA, Regezi JA. Cystic ameloblastoma: Behavior and treatment of 21 cases. J Oral Maxillofac Surg 2001; 59:1311-6.

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4.

Amedee RG, Dhurandhar NR. Fine-needle aspiration biopsy. Laryngoscope 2001;111:1551-7. 5. Layfield LJ. Fine-needle aspiration of the head and neck. Pathology (Phila). 1996;4:409-38. 6. Stewart CJ, MacKenzie K, McGarry GW, Mowat A. Fine-needle aspiration cytology of salivary gland: A review of 341 cases. Diagn Cytopathol 2000;22:139-46. 7. Saleh HA, Clayman L, Masri H. Fine needle aspiration biopsy of intraoral and oropharyngeal mass lesions. Cytojournal 2008;5:4. 8. Stamatakos MD, Houston GD, Fowler CB, Boyd E, Solanki PH. Diagnosis of ameloblastoma of the maxilla by fine needle aspiration. A case report. Acta Cytol 1995;39:817-20. 9. Günhan O. Fine needle aspiration cytology of ameloblastoma. A report of 10 cases. Acta Cytol 1996;40:967-9. 10. Kaliamoorthy S, Venkatapathy R, Babu P, Veeran V. Practical significance of utilizing fine needle aspiration cytology as an adjunct diagnostic aid

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in the preoperative presumptive diagnosis of ameloblastoma. J Cytol 2013;30:247-51. 11. Radhika S, Nijhawan R, Das A, Dey P. Ameloblastoma of the mandible: Diagnosis by fine-needle aspiration cytology. Diagn Cytopathol 1993;9:310-3. 12. Mathew S, Rappaport K, Ali SZ, Busseniers AE, Rosenthal DL. Ameloblastoma. Cytologic findings and literature review. Acta Cytol 1997;41:955-60. 13. Parate SN, Anshu, Helwatkar SB, Munshi MM. Cytology of recurrent ameloblastoma with malignant change. A case report. Acta Cytol 1999;43:1105-7. How to cite this article: Chandavarkar V, Uma K, Mishra M, Sangeetha R, Gupta R, Sharma R. Ameloblastoma: Cytopathologic profile of 12 cases and literature review. J Cytol 2014;31:161-4. Source of Support: Nil, Conflict of Interest: None declared.

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Ameloblastoma: Cytopathologic profile of 12 cases and literature review.

Fine-needle aspiration cytology (FNAC) has been used as a diagnostic tool in evaluating suspected lesions. It shows a high diagnostic accuracy for dia...
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