Histological examination
Sections from the left and right ocular tumors showed a picture of small round cell tumor with high mitotic activity and tumor necrosis. The tumor cells possessed neuroendocrine immunophenotype (NSE and synaptophysin positivity). Diagnosis of Rb was established.
The sections from the left orbital and left tibia/femoral tumors revealed chondroblastic and osteoblastic osteosarcoma, respectively, with high grade, bizarre tumor cells proliferation and osteioid production. The former sample also showed excess amount of malignant cartilaginous component. The lung tumour showed classical osteoblastic osteosarcoma indicating the metastatic nature from the lower leg. Key histological features are shown in Figure 1 .