Abstract
Purpose:
Feline ocular post-traumatic sarcomas (FOPTS) are malignant intraocular neoplasms that are frequently associated with a history of ocular trauma and chronic inflammation. However, the tumorigenesis of FOPTS is unknown. In this study, we evaluated the possible association between the epithelial mesenchymal transition (EMT) of lens epithelial cells (LEC) and the tumorigenesis of FOPTS.
Methods:
The database of the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) was searched and records of FOPTS spindle cell variant were examined. FOPTS spindle cell variant were divided into 4 categories: Spindle cell metaplasia (No tumor but LECs have proliferated), Early FOPTS (LECs were extending beyond the lens capsule), Full FOPTS (Fully developed tumors which have spread entirely around the eye), and Extensive FOPTS (Fully developed tumors extend beyond the sclera). 17 cases from each category were examined immunohistochemical phenotypes. Immunohistochemistry were performed to detect expression of Pancytokeratin (P-CK: AE1/AE3), Vimentin, α-SMA, S100A4, and Ki-67. We also compared the number of P-CK and α-SMA positive case of the inside and outside the lens capsule.
Results:
In all cases, tumor cells were positive for Vimentin and S100A4. The number of P-CK positive cases gradually decreased with tumor progression. On the other hand, the number of α-SMA positive cases gradually increased with tumor progression. Ki-67 labeling index also gradually increased with tumor progression. In cases of early FOPTS intracapsular LECs were more frequently P-CK positive than extracapsular LECs and extracapsular LECs were more frequently α-SMA positive than intracapsular LECs. However, there was no significant difference between the number of P-CK and α-SMA positive cells of the inside and outside the lens capsule in Full FOPTS.
Conclusions:
In FOPTS, EMT phenomenon was enhanced with the category progression. Our immunohistochemical findings were suggested that lens epithelial cells might associate with tumorigenesis of FOPTS.