PEDT-04 SIX CASES OF RETINOBLASTOMA WITH CNS INVOLVEMENT

Although the survival rate of intraocular retinoblastoma (RB) is nearly 100%, the outcome of central nervous system (CNS) involvement or Trilateral retinoblastoma (TRb: very rare RB which associated with brain tumor) is dismal. We retrospectively reviewed our six cases of these rare tumors. Their ages at diagnosis are 0y3m-1y10m (median 1y3m) (Male 4, Female 2). Only one had RB family history. Their affected eyes were bilateral 2, unilateral 3 and no 1. Their CNS diseases were suprasellar tumor 3, pineal tumor 1 and cerebrospinal fluid (CSF) cytology positive 2. Two of the suprasellar tumor patients had spinal metastasis. Three of the six patients were TRb. One TRb patient was treated with chemotherapy and high-dose chemotherapy without radiotherapy. Although he suffered with secondary osteosarcoma seven years later, he got complete remission and alive 5 years more without any tumor recurrence. The second TRb patient was treated with chemotherapy and local radiotherapy but relapsed 20 months later. The third TRb patient was chemotherapy resistant. Two CSF positive patients had optic nerve invasion. One patient with chiasm invasion died 11 months later because of treatment resistance. The other patient with optic nerve invasion before optic canal had no CNS tumor nor CSF involvement at diagnosis. Chemotherapy before enucleation was given to avoid dissemination. However, CSF cytology became positive after enucleation and remained even with intensified chemotherapy. Finally, he got remission with radiotherapy and high-dose chemotherapy, and alive without disease for 3.8 years. The last patient had suprasellar genetically classified retinoblastoma tumor and cerebrospinal metastasis. This patient showed good chemotherapy response and is still under treatment. Even with &quotso called° fatal RB cases, some case could survive with intensified therapy. Data accumulation is necessary for better survival of these tumors.