Trilateral retinoblastoma is characterized by retinal tumors in one or both eyes, as well as tumors of the pineal gland or parasellar region of the brain. Here we describe a 4-month-old girl, presenting with pituitary dysfunction, hypothalamic overgrowth syndrome and central blindness, in addition to suprasellar and bilateral retinal tumors. Biopsy of the suprasellar tumor confirmed the diagnosis of trilateral retinoblastoma. After biopsy, cerebrospinal fluid (CSF) metastasis was discovered. Overgrowth persisted, but blindness and pituitary dysfunction resolved when the suprasellar tumor and CSF metastasis responded to cyclosporine-modulated systemic chemotherapy with intraventricular chemotherapy, consolidated with marrow-ablative chemotherapy and stem cell rescue of the bone marrow. Twenty months after diagnosis and 12 months after transplant, an unusual pattern of tumor recurrence was observed along the catheter of the Ommaya reservoir used for delivering intraventricular chemotherapy, which was also at the site of the previous suprasellar needle biopsy. Salvage therapy consisted of resection, stereotactic radiation, and further systemic and intraventricular chemotherapy. At 25 months after diagnosis, the patient was developing well and seeing better. However, she died 32 months after diagnosis despite the salvage therapy. This case highlights the possibility of tumor dissemination after needle biopsy of a suprasellar tumor. Biopsy may be avoided if a characteristic clinicoradiological picture of trilateral retinoblastoma is recognized. We recommend that if a pineal or suprasellar tumor is observed in a child, the eyes should be examined for retinoblastoma, thereby avoiding biopsies of the intracranial tumor, which may track difficult-to-treat tumor cells through the brain, and disseminate tumor cells into the CSF.