|LETTER TO THE EDITOR
|Year : 2015 | Volume
| Issue : 2 | Page : 234-235
Ameloblastic carcinoma: An effort to abridge this diagnostic challenge!
S Routray1, S Majumdar2, N Swain3
1 Department of Oral Pathology and Microbiology, Institute of Dental sciences, Bhubaneswar, Odisha, India
2 Department of Oral Pathology and Microbiology, GITAM Dental College and Hospital, Gandhinagar Campus, Rushikonda, Visakhapatanam, India
3 Department of Oral Pathology and Microbiology, M.G.M Dental College and Hospital, Navi Mumbai, Maharastra, India
|Date of Web Publication||5-Feb-2016|
Department of Oral Pathology and Microbiology, Institute of Dental sciences, Bhubaneswar, Odisha
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Routray S, Majumdar S, Swain N. Ameloblastic carcinoma: An effort to abridge this diagnostic challenge!. Indian J Cancer 2015;52:234-5
World Health Organization classification in 2005 defined; ameloblastomas in which there is histologic evidence of malignancy in the primary tumor or the recurrent tumor, regardless of whether it has metastasized should be termed as ameloblastic carcinomas (AC). But the parameters mandatory to distinguish how extensive a feature should be to diagnose a case as AC, is still oblivious. A medline search for reported cases of AC between 1984-2011, interestingly showed a total one hundred twenty three cases; suggestive of the scanty matter available to draw any conclusive parameters for diagnosis. Hence our main aim is to highlight the points associated with this entity for simplifying the diagnosis. The clinical, radiographic and histological details of our institution cases are also presented along with the discussion in [Table 1].
|Table 1: Tabular representation of clinical and pathological features of the 3 cases|
Click here to view
Hall et al. suggested four clinical criteria for diagnosis of AC; rapid growth, propensity to perforate the cortex, pain and paresthesia, that are distinct from their benign counterpart. They also specified the histopathological parameters such as the presence of sheets, islands or trabeculae of epithelium, the absence of stellate reticulum-like structures and round to spindled epithelial cells with little or no differentiation toward the columnar cell morphology of ameloblastoma positive for malignant transformation. Gnepp emphasized that dysplastic cytopathological features along with ameloblastic differentiation should be mandatory to give a conclusive diagnosis. In a recent review from the year 2005 till -2011, 31 cases were reported which mostly represented the secondary variant of AC. The authors stated that tumors with plexiform pattern, hyperchromatism, mitosis and necrosis as features were associated with a higher ratio of recurrence and death and that tumors with clear cells appeared to correlate with recurrence and mortality.
Among all the reviewed cases in literature till present time, 27% of ameloblastic carcinoma was misdiagnosed as benign counterpart at first hispathological diagnosis. Similarly in our cases, the radiographic appearance of the lesion and histopathological features were consistent with that of an ameloblastoma in incisional biopsy report. On excisional biopsy, the patient's tissue sample of Case 3 showed:
- Pleomorphism and high mitotic activity of irregularly arranged epithelial cells in cords and nests with acute inflammation [Figure 1]
- Tall columnar cells showing high pleomorphism with nuclear atypia and mitotic activity [Figure 2]
- Among the nests and cords of ameloblastic differentiated cells areas of squamous metaplasia with keratin pearl formation was also observed [Figure 3].
|Figure 1: Ameloblastic differentiated cells arranged in lining or cords with pleomorphism|
Click here to view
|Figure 2: Inflammatory component with marked cellular atypia of ameloblastic lining|
Click here to view
|Figure 3: Areas of squamous metaplasia and keratin pearling midst of ameloblastic lining epithelium|
Click here to view
All the above features were suggestive of malignancy correlative of AC, though in our cases we did not observe necrosis or vascular invasion as reported in some earlier cases. Therefore we would strongly recommend for a pathologist, a more comprehensive review of every bit tissue specimen received (incisional and excisional) so as to avoid least possibility of evading a proper diagnosis. Further investigations like immunohistochemistry (IHC) should be conducted without any prejudice to rule out AC. IHC markers like α-smooth muscle actin (α-SMA), CK18, parenchymal MMP-2, stromal MMP-9, and Ki-67 can be useful in diagnosis of AC.
For a surgeon, surgical resection with 10-15 mm margin free of tumour as recommended consistently. Particularly in the maxilla, extent of the resection may be limited related to adjacent important anatomical structures. Adjuvant radiotherapy in patients with positive resection margins, multiple positive lymph nodes, extracapsular spread, perineural invasion, and in patients where salvage surgery would be inefficient. Regular follow-up and CT or MRI controls should be significantly followed among clinicians due to their tendency to reccur. To prevent late recurrences, longtime follow up should be mandatory.
| » References|| |
Barnes L, Eveson J, Reichart P, Sidransky D. Pathology and genetics of tumors of the head and neck. Lyon, France: International Agency for Research on Cancer (IARC) Press; 2005. p. 286-95.
Hall JM, Weathers DR, Unni KK. Ameloblastic carcinoma: An analysis of 14 cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;103:799-807.
Gnepp DR. Diagnostic Surgical Pathology of the Head and Neck. 2nd
ed. Saunders Elsevier; 2009. p. 809-10.
Casaroto AR, Toledo GL, Filho JL, Soares CT, Capelari MM, Lara VS. Ameloblastic carcinoma, primary type: Case report, immunohistochemical analysis and literature review. Anticancer Res 2012;32:1515-25.
Yoon HJ, Jo BC, Shin WJ, Cho YA, Lee JI, Hong SP, et al
. Comparative immunohistochemical study of ameloblastoma and ameloblastic carcinoma. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;112:767-76.
Zwahlen RA, Grätz KW. Maxillary ameloblastomas: A review of the literature and of a 15-year database. J Craniomaxillofac Surg 2002;30:273-9.
[Figure 1], [Figure 2], [Figure 3]