[Morphologic classification of choroidal invasion of retinoblastoma].

In order to inquire into standard for morphologic classification of choroidal invasion of retinoblastoma and to study the tumor clinic--pathologic further under the integrated scale, the changes of retinal pigment epithelium, Bruch's membrane and choroid on the histopathological sectins of 297 cases of primary enucleated eyes of retinoblastoma were retrospectively observed under the light microscopy. The choroidal invasion was morphologically divided into four stages: Stage 1, only retinal pigment epithelium involved, the Bruch's membrane was intact; Stage 2, the Bruch's membrane was destroyed and the choroidal capillaris was not infiltrated; Stage 3, choroial capillary and middle blood vessel layer in small limits were infiltrated; Stage 4, invasion involved in choroid in great limits and involvement of sclera existed simultaneously. This classification (also called pigment epithel--choroid stage, PEC--stage) reflected both infiltrated procedure of tumor cells and preventive mechanism in eye and morphological criterion half--quantitatively. It can be used as a united standard to compare the infiltration degree of retinoblastoma among different individuals and different studies.