Late solitary skeletal metastasis to the patella from retinoblastoma.

Isolate metastasis to the patella is rare. A young girl treated with bilateral enucleation for retinoblastoma, reported 9 years later with solitary patellar metastasis. Treatment options for distant metastasis from retinoblastoma are not well defined but include combinations of chemotherapy, radiotherapy and surgery. Late skeletal metastasis from retinoblastoma should be differentiated from second primary bone malignancies, with immunohistochemistry, cytogenetic and electron microscopic features, as the prognosis and management are different.