Outcome of Vision Impairment and Diabetes Insipidus in Suprasellar Region Germinoma

Aim: Many cases of suprasellar region germinoma occurs in diabetes insipidus (DI), but a patient initially may come to the hospital for the chief complaint of visual impairment. The aim of this study is to determine the etiology of initial symptom presentation and the outcomes of visual impairment and DI in suprasellar region germinoma. Methods: We investigated eleven cases of single lesion suprasellar germinomas that were diagnosed and treated in our hospital. For each, a magnetic resonance imaging (MRI) was performed. Results: At the hospital visit, decreased visual acuity was found in 5/11 cases, while DI was found in all cases. The decreased visual acuity was improved in 4/5 cases by treatment, but DI improved in only 2/11 cases. In 10 cases, DI occurred earlier than visual impairment. As the initial symptom, visual impairment occurred earlier than DI in only one case and did not improve by treatment. In this case, a pituitary stalk of the normal thickness could be identified by MRI, and the optic nerve was swollen. In ten cases except this case, no significant enlargement of optic nerve was detected, and a swollen pituitary stalk was confirmed. Conclusions: In suprasellar germinomas, it is rare, but the optic nerve can significantly swell at onset, while the pituitary stalk may be intact. In such cases, visual impairment occurs earlier than DI, and visual impairment may not be improved.