Optic nerve and chiasmal germinoma.

A 15-year-old boy presented with visual acuity of 20/200 OD and no light perception OS. The anterior segment of the left eye showed a relative afferent pupillary defect. A large (4.5 x 4.5 x 2.0 mm) infiltrative optic nerve head lesion with dilated vessels was seen OS with disc pallor OD. MRI of the brain and orbit revealed lobulated optic nerve thickening and chiasm. A biopsy revealed features consistent with germinoma and was positive for marker placental alkaline phosphatase. Systemic examination, chest x-ray, abdominal ultrasound, cerebrospinal fluid, and serology were normal. He received 27 Gy to the craniospinal region followed by a boost of 27 Gy to the left optic nerve. Eight months postirradiation, vision stabilization was achieved with 20/200 OD and light perception with inaccurate projection of rays OS.