Immunohistochemical properties of ocular adenomas, adenocarcinomas and medulloepitheliomas

Abstract

A Senior Honors Thesis:Presented in partial fulfillment of the requirements for graduation with distinction in Zoology in the undergraduate college of Arts and Sciences of The Ohio State University. By Abstract:Ocular medulloepitheliomas, adenomas and adenocarcinomas share a common phenotype and originate from the cells of the ciliary epithelium. This can make it very difficult to differentiate between these tumors histopathologically. Therefore, this study focused on identifying a combination of immunological markers that might be used in the diagnosis of these tumors. These markers included AE1/AE3, CK7, CK20, and telomerase reverse transcriptase (TERT).Routine immunohistochemical staining was performed on twenty-one whole globes diagnosed with one of these tumors. The tumors that immunostained for TERT showed increasing immunoreactivity as the tumor types increased in aggressiveness. None of the tumor types were immunopositive for CK7. CK20 immunostaining was found in the adenomas but not in the adenocarcinomas or medulloepitheiomas. AE1/AE3 expression was present more consistently in the adenocarcinomas and less frequently in the adenomas. There was no AE1/AE3 expression in the medulloepitheliomas confirming their mesenchymal origin.Furthermore, CK20 and TERT show inverse expression patterns, i.e., TERT increases in expression and CK20 decreases in expression with increasing aggressiveness. These results may be important diagnostic and prognostic indicators for these tumors. (195 words)

Canine ocular neoplasia: a review

“…Mimicking normal neuroepithelium, iridociliary adenomas are immunoreactive for vimentin and neuron‐specific enolase (NSE) with variable immunopositivity for S100, glial fibrillary acidic protein (GFAP), and desmin. There is also immunoreaction to telomerase reverse transcriptase (TERT), and some neoplasms express cytokeratins …”

“…Iridociliary adenocarcinomas are immunoreactive for vimentin, NSE and TERT with variable immunopositivity for S100, cytokeratin, GFAP and desmin. Malignant iridociliary neoplasms have increased TERT expression and are more likely to express cytokeratin than benign tumors …”

Considerations about ocular neoplasia of dogs and cats

“…Immunohistochemistry showed that citokeratin AE1 and citokeratin AE3 were more consistently expressed in adenocarcinomas and less frequently in the adenomas, whereas none of the tumor types were positive for citokeratin 7. In regard to aggressiveness, an inverse expression pattern was seen to citokeratin 20 (decreased in adenocarcinomas and increased in adenomas) and telomerase reverse transcriptase (increased in adenocarcinomas and decreased in adenomas) (KLOSTERMAN et al, 2006).…”

“…Masses display different patterns of pigmentation and invasiveness, are solid or pedunculated (KLOSTERMAN et al, 2006), and usually arise from the nonpigmentated epithelium of the ciliary body (WILLIS & WILKIE, 2001). Golden Retriever and Retriever Labradors have been reported as predisposed breeds (WILLIS & WILKIE, 2001).…”

Ocular glioneuroma with medulloepitheliomatous differentiation in a goldfish (Carassius auratus)

“…This rare congenital embryonic tumor is reported in pediatric or young human patients. 1,14,19,31 Medulloepithelioma is a very rare tumor in dogs 2,8,15,26 and horses, 18 and is extremely rare in cats. 12 Isolated cases have been reported in other species, including birds 5 and llamas.…”