Most common second malignancy in patients with femoral retinoblastoma is

Patients with family retinoblastoma are at greatly increased risk of developing Osteosarcoma and and some other soft tissue sarcoma.. Alteration in RB pathway, involving INK proteins, cyclin D dependent kinases, and RB family proteins which are present in normal cells lead on to tumor suppressor gene. And associated somatic tissue mutation cause increased risk of other tumors. Refer robbins 9/e 299