Odontogenic Carcinosarcoma: Clinicopathologic Features of 2 Cases

Abstract

This study reports 2 odontogenic carcinosarcomas, including the clinicopathologic and immunoprofile characteristics of these rare tumors. The first case occurred in a 22-year-old male presenting a bilobular mass involving the gingiva and bone of the premolar region of the left mandible, with paresthesia of the lower lip. Microscopic examination revealed a tumor similar to ameloblastic fibrosarcoma, with atypical mesenchymal cells; however, the odontogenic epithelium also showed atypia. In the second case, a 16-year-old female had a painless, asymptomatic, large intraosseous mandibular lesion. The patient received radiotherapy to treat a rhabdomyosarcoma of the parotid 13 years before. The tumor was composed of atypical spindle cells, positive for vimentin and smooth muscle actin, intermingled with malignant odontogenic epithelium. Both epithelial and mesenchymal components of the tumors showed high index of p53- and Ki67-positive cells. The first case was diagnosed as odontogenic carcinosarcoma possibly originated from an ameloblastic fibrosarcoma, and the second as de novo odontogenic carcinosarcoma possibly caused by previous radiotherapy.

Case Report: Odontogenic carcinosarcoma arising from premature odontoma with immunohistochemical profile

“…The proliferative index Ki-67 in our case was around 7.5% in the epithelial component and 3% in the ectomesenchymal component. This is in accordance with the work of Dos Santos et al (2018) and Soares et al (2019), who found that Ki-67 index was higher in the epithelial component than the ectomesenchymal component [4][5][6][7] .…”

“…The current case showed multiple radiopacities; may be due to the preexisting immature odontoma. atypia, and spindle cell variant of ameloblastic carcinoma, which lacks the ectomesenchymal component [2][3][4][5][6][7][8] . In the present case, there was a patchy positive expression of vimentin in the epithelial component.…”

“…In the present case, there was a patchy positive expression of vimentin in the epithelial component. This could be explained as OCS undergoes epithelial mesenchymal transition, a process in which the polarized immotile epithelial cell changes to gain the mesenchymal phenotype and indicates more aggressive behavior of the neoplasm 7,12,13 .…”

“…Regarding the clinical behavior of OCS, it is a highly aggressive highly recurrent malignant neoplasm 7 . In our case, the patient encountered recurrence of the lesion after 9 months follow up with no evident metastasis.…”

“…OCS has been added again in the 2017 edition because of the availability of cases with adequate diagnostic immunohistochemical and molecular criteria 5,6 . Owing to the scarcity of reported cases -only eleven reported cases in the English literature -OCS clinical behavior remains unexplored 7,8 . In the current work, we report a case of OCS with the detailed clinical, radiographic, histopathological and immunohistochemical description.…”