Diabetes insipidus with impaired vision caused by germinoma and perioptic meningeal seeding: A case report

BACKGROUND: Germinoma is a type of germ cell tumor that most frequently arises in the midline axis of the brain. Impaired vision is a clinical manifestation of germinnoma. Although rare, intracranial germinoma seeding to the perioptic arachnoid space is one cause of visual acuity decrease. CASE SUMMARY: An 11yearold girl who presented with polyuria and polydipsia and subsequently developed diminution of vision. Imaging showed bilateral heterogeneous enhancement of the optic nerve sheaths and atrophy of the optic nerve, and transsphenoidal biopsy revealed a germinoma. The patient experienced poor visual recovery following chemotherapy and radiotherapy. Germinomas are rare and they are mostly identified in children and adolescents. The manifestations include diabetes insipidus, pituitary dysfunction, visual complaints, etc. The mechanisms that lead to visual loss include intracranial hypertension, compression of optic chiasma, and tumor invasion. A literature review was performed to summarize the cases with a tumor infiltrating the optic nerve. Most of the reported patients were adolescents and presented with anterior pituitary hormone deficiency. Enhancement of optic nerve sheaths and optic disc pallor could be identified in most of the cases. The purpose of this report is to provide awareness that in cases where a germinoma is associated with visual loss, though rare, perioptic meningeal seeding should be taken into consideration. CONCLUSION: The case report suggests that children with diabetes insipidus need a complete differential diagnosis.