Indian Journal of Pathology and Microbiology

CASE REPORT
Year
: 2015  |  Volume : 58  |  Issue : 4  |  Page : 513--515

Spindle-cell ameloblastic carcinoma of the maxilla with adenoid cystic carcinoma-like areas: A new variant?


Hena A Ansari1, Prasenjit Sen Ray1, Nazoora Khan1, Arshad Hafiz Khan2,  
1 Department of Pathology, Jawaharlal Nehru Medical College, Aligarh Muslim University, Aligarh, Uttar Pradesh, India
2 Department of Plastic Surgery, Jawaharlal Nehru Medical College, Aligarh Muslim University, Aligarh, Uttar Pradesh, India

Correspondence Address:
Dr. Hena A Ansari
Department of Pathology, Jawaharlal Nehru Medical College, Aligarh Muslim University, Aligarh - 202 002, Uttar Pradesh
India

Abstract

Ameloblastic carcinoma is a rare aggressive malignancy of odontogenic epithelial origin. The disease has been reported to afflict people over a wide range of age group without any sex predilection. It is characterized by rapid growth and destruction of overlying bones along with involvement of adjacent soft tissues. The overall prognosis of this cancer is poor despite radical surgery and radiotherapy. Owing to the rarity of this lesion, complete data on the biological behavior and response to different treatment modalities are still lacking. The authors hereby report a case of this uncommon tumor arising from left maxilla in a 60-year-old Indian male. Histopathological examination of the tumor showed foci of spindling intermixed with large areas of tumor cells arranged in cribriform pattern and having luminal eosinophilic material which was reminiscent of adenoid cystic carcinoma. A final diagnosis was achieved after immunohistochemical study. These unusual findings prompted this case report.



How to cite this article:
Ansari HA, Ray PS, Khan N, Khan AH. Spindle-cell ameloblastic carcinoma of the maxilla with adenoid cystic carcinoma-like areas: A new variant?.Indian J Pathol Microbiol 2015;58:513-515


How to cite this URL:
Ansari HA, Ray PS, Khan N, Khan AH. Spindle-cell ameloblastic carcinoma of the maxilla with adenoid cystic carcinoma-like areas: A new variant?. Indian J Pathol Microbiol [serial online] 2015 [cited 2019 Aug 17 ];58:513-515
Available from: http://www.ijpmonline.org/text.asp?2015/58/4/513/168856


Full Text

 Introduction



Ameloblastic carcinoma is a rare aggressive malignancy of odontogenic epithelial origin. It is characterized by rapid growth and destruction of overlying bones along with involvement of adjacent soft tissues. This lesion predominantly involves the maxillofacial region with around 66% cases located in the mandible. Regional lymph node and distant metastasis have been observed.[1]

Owing to the rarity of this lesion, complete data on demography, biological behavior and treatment modalities are still lacking. The authors report an unusual case of this tumor arising from the maxilla in a 60-year-old Indian male. Histopathological examination showed focal features of ameloblastic carcinoma, having areas of spindling confluent with nests of tumor cells arranged in cribriform pattern and having luminal eosinophilic material, which was reminiscent of adenoid cystic carcinoma (ACC). Immunohistochemically, the lesion stained weakly positive for CK7 and alpha-smooth muscle actin (SMA) (focally) whereas CK19 and CD117 were negative. Thus, a final diagnosis of ameloblastic carcinoma (spindle cell variant) was offered. These unusual histopathological and immunohistochemical findings prompted this case report.

 Case Report



A 60-year-old Indian male patient presented with pain around the left side of the cheek over 4 months along with gradually increasing stuffiness of nose and difficulty in eating. This was accompanied by the appearance of swelling over the same region in past 2 months. Clinical evaluation showed a firm to hard, diffuse, tender growth involving soft tissue of the cheek overlying left maxilla, which was fixed to underlying bone. On examination of the oral cavity, perforation of the hard palate and fistulous communication with the nasal cavity was noted. Preauricular and cervical lymph nodes were not palpable, and no evidence of neurodeficit was elicited. A provisional diagnosis of malignant growth of left maxilla was made. Coincidentally the patient gave a history of tumor in his left eye which was treated in this same hospital 10 years ago. Search from the institutional archival records revealed that he had undergone the enucleation of his left eye for a tumor that was histopathologically diagnosed as sebaceous cell carcinoma arising from left upper eyelid.

Computed tomography scan of the head and neck revealed a heterogeneous tumor mass arising in the left maxillary sinus, which extended laterally into facial soft tissue with bony permeation. Medially, left sided nasal turbinates were destroyed and palatine process of maxilla was eroded by the tumor [Figure 1]a. No evidence of lymphadenopathy was observed. A left maxillectomy was performed.{Figure 1}

On gross examination, an irregular tumor measuring 6 cm × 3 cm × 2 cm was detected in the maxillary sinus extending upwards to the zygoma, with permeation through adjacent bones and soft tissue involvement. Hard palate was eroded. The tumor was partly whitish and partly variegated in appearance with multiple foci of hemorrhage and necrosis [Figure 1]b. Microscopically, sections from the tumor showed irregular nests, sheets and groups of malignant cells having small basaloid as well as oval to spindled nuclei with coarse chromatin, pleomorphism, moderate amount of eosinophilic cytoplasm and high mitotic activity (7-8/10 hpf). Peripheral palisading with reverse nuclear polarity and stellate reticulum appearance were observed in focal areas. Confluent with these areas, nests of tumor cells were also found to be arranged in cribriform pattern with luminal eosinophilic hyaline-like material, which was reminiscent of adenoid cystic carcinoma [Figure 2]. Perineural invasion, necrosis and mononuclear cell inflammation in stroma were present. Based on these, a differential diagnosis between ameloblastic carcinoma and adenoid cystic carcinomawas offered.{Figure 2}

Periodic acid-Schiff stain showed only weak variable positivity in tumour cell islands, which went against a definite diagnosis of ACC. Immunohistochemically, the tumor cells were positive for alpha SMA focally inside the cell nests but negative at the periphery of the nests. CK7 was weakly positive while CK19 was negative in tumor islands. No immunoreactivity to CD117 was noted in the ACC-like areas [Figure 3]. Thus, a final diagnosis of spindle-cell ameloblastic carcinoma was made. As surgical margins were positive for malignancy, postoperative radiotherapy was advised. However, unfortunately, the patient was lost in follow-up.{Figure 3}

 Discussion



Ameloblastic carcinoma is a rare tumor whose exact incidence is not known — The World Health Organization has defined the primary form of ameloblastic carcinoma as "a rare primary odontogenic malignancy that combines the histological features of ameloblastoma with cytological atypia, even in the absence of metastasis."[1]

The tumor can occur in two forms — primary, when it arises de novo and secondary, when it originates from preexisting ameloblastoma. The latter is also known as dedifferentiated ameloblastoma.[2]

The tumor predominantly involves the mandible (66% of cases) with a predilection for the posterior alveolar part; only 19 cases have been reported in maxilla.[1],[2],[3],[4]

Patients suffering from this tumor present with rapidly enlarging painful mass in the maxillo-facial region. Bleeding, ulceration and malocclusion of teeth can be associated. Presence of parasthesia is indicative of perineural invasion by the tumor. Perforation of cortical plates and extension into adjacent soft tissues are frequently associated.[1],[2],[3] In addition, tumors arising in maxilla can grow into the nasal cavity causing stuffiness of nose, epistaxis, trismus and dysphonia.[3],[4]

Spindle cell differentiation in ameloblastic carcinomas is considered a rare histological feature. To the best of our knowledge, only six cases have been reported to date as spindle cell ameloblastic carcinoma.[2],[5],[6],[7],[8],[9],[10],[11] Our case presented a highly unusual and striking combination of spindle cell areas, foci resembling ACC and occasional residual areas of ameloblastic epithelium.

Immunohistochemical expression of cytokeratins, namely CK 5, 7, 17, 18 and 19 have been demonstrated in human odontogenic epithelial cells and these markers can be effectively used to specify the histogenesis of ameloblastic tumors.[11] However, questions have remained on whether the expression pattern remains same in benign and malignant tumors.

Smooth muscle actin and c-kit (CD 117) can help in differentiating ameloblastic carcinomas with ACC-like areas from true adenoid cystic carcinomas of the jaw. SMA is expressed in the myoepithelial cell layer in adenoid cystic carcinoma while it is expressed within the cell islands in ameloblastic carcinomas.[12] Again, c-kit is positive in true ACCs (while it would be negative in ameloblastic carcinomas).[13]

In the context of the present case, ACC came into the differential as islands of the tumor cells were focally arranged in cribriform pattern with the luminal eosinophilic hyaline-like material. However, presence of the reversed nuclear polarity peripherally and typical stellate reticulum pattern of growth combined with the immunohistochemical profile for (CD117 and CK19 negativity, weak CK7 positivity, and focal SMA uptake in epithelial islands) turned the diagnosis in favor of ameloblastic carcinoma. We hereby propose that the spindle and ACC-like components represent a hitherto unreported hybrid variant of ameloblastic carcinoma that has a separate pattern of immunoexpression, that is, loss of normal expression profile. However, questions pertaining to whether this is a sign of de-differentiation, its association with prognosis and treatment are yet to be answered and thereby this remains a potential area of research in future.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Sciubba JJ, Eversole LR, Slootweg PJ. Odontogenic/ameloblastic carcinomas. In: Barnes L, Eveson JW, Reichart P, Sidransky D, editors. World Health Organization Classification of Tumours: Pathology and Genetics of Head and Neck Tumours. Lyon: IARC Press; 2005. p. 287-9.
2Slootweg PJ, Müller H. Malignant ameloblastoma or ameloblastic carcinoma. Oral Surg Oral Med Oral Pathol 1984;57:168-76.
3Corio RL, Goldblatt LI, Edwards PA, Hartman KS. Ameloblastic carcinoma: A clinicopathologic study and assessment of eight cases. Oral Surg Oral Med Oral Pathol 1987;64:570-6.
4Dhir K, Sciubba J, Tufano RP. Ameloblastic carcinoma of the maxilla. Oral Oncol 2003;39:736-41.
5Nagai N, Takeshita N, Nagatsuka H, Inoue M, Nishijima K, Nojima T, et al. Ameloblastic carcinoma: Case report and review. J Oral Pathol Med 1991;20:460-3.
6Infante-Cossio P, Hernandez-Guisado JM, Fernandez-Machin P, Garcia-Perla A, Rollon-Mayordomo A, Gutierrez-Perez JL. Ameloblastic carcinoma of the maxilla: A report of 3 cases. J Craniomaxillofac Surg 1998;26:159-62.
7Lau SK, Tideman H, Wu PC. Ameloblastic carcinoma of the jaws. A report of two cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1998;85:78-81.
8Kawauchi S, Hayatsu Y, Takahashi M, Furuya T, Oga A, Niwa S, et al. Spindle-cell ameloblastic carcinoma: A case report with immunohistochemical, ultrastructural, and comparative genomic hybridization analyses. Oncol Rep 2003;10:31-4.
9Ismail SB, Zain RB, Yaacob HB, Abraham MT. Ameloblastic carcinoma (spindle cell variant). Pathology 2009;41:292-5.
10Jindal C, Palaskar S, Kaur H, Shankari M. Low-grade spindle-cell ameloblastic carcinoma: Report of an unusual case with immunohistochemical findings and review of the literature. Curr Oncol 2010;17:52-7.
11Angiero F, Borloni R, Macchi M, Stefani M. Ameloblastic carcinoma of the maxillary sinus. Anticancer Res 2008;28:3847-54.
12Bello IO, Alanen K, Slootweg PJ, Salo T. Alpha-smooth muscle actin within epithelial islands is predictive of ameloblastic carcinoma. Oral Oncol 2009;45:760-5.
13Terada T. Adenoid cystic carcinoma of the oral cavity: Immunohistochemical study of four cases. Int J Clin Exp Pathol 2013;6:932-8.