1/2. Histopathologic changes in retinoblastoma after chemoreduction.PURPOSE: To report the histologic findings in the eyes of two patients with bilateral retinoblastoma who underwent chemoreduction therapy and enucleation of one eye. methods: Clinical histories were obtained for both patients. The enucleated eyes were routinely processed and sections were stained with hematoxylin and eosin. RESULTS: The first patient underwent two cycles of carboplatin, vincristine, and etoposide, and the second patient underwent one cycle of carboplatin, vincristine, and etoposide before enucleation. The eyes of both patients exhibited a clinical type 3 regression pattern. Histopathologic examination showed a gliotic mass with interspersed calcifications in one eye and necrotic tumor adjacent to histologically intact retinoblastoma in the other eye. CONCLUSION: Chemoreduction has variable effects on retinoblastoma and the clinical type 3 regression pattern has several histologic counterparts.- - - - - - - - - - ranking = 1keywords = cycle (Clic here for more details about this article) |
2/2. Retinoinvasive malignant melanoma of the uvea.AIMS: To define a retinoinvasive phenotype of uveal melanoma based on an informative case and survey of literature. methods: A 65-year-old woman developed a circumscribed mixed cell type melanoma of the ciliary body that was locally excised. After 6 years, secondary glaucoma evolved. Three years later a ring melanoma was diagnosed and the eye was enucleated. The histopathological material was analysed by immunohistochemistry. RESULTS: A spindle cell type ring melanoma infiltrated the iris and ciliary body diffusely, and extended through the aqueous outflow channels and iridocyclectomy flap extrasclerally. The choroid was uninvolved. Instead, tumour cells spread to the vitreous and along the ciliary epithelium, adhered to the hyaloid face and retinal surface, and extensively invaded the neuroretina, the retrobulbar optic nerve, and perineural space. They were labelled for S-100 protein, vimentin, and in the neuroretina for cytokeratins 8 and 18. No evidence of systemic disease is evident 5 years after enucleation. Three identical tumours of the iris and ciliary body that extensively infiltrated the neuroretina and retrobulbar optic nerve were identified from previous literature. CONCLUSION: Retinoinvasive melanoma is a rare but distinct phenotype of uveal melanoma, different from circumscribed and most diffuse melanomas that may erode the overlying retina and infiltrate the optic nerve that do not invade non-adjacent retina. Retinoinvasive tumours tend to evolve from a ring melanoma and they grow slowly, which may favour emergence of tumour clones able to migrate, adhere to, and invade into the neuroretina, analogous to the metastatic cascade. Frequent secondary angle closure glaucoma may promote invasion into the optic nerve.- - - - - - - - - - ranking = 0.5keywords = cycle (Clic here for more details about this article) |