Physiologic pituitary hyperplasia causing visual disturbance during adolescence.

We report for the first time two cases of physiologic pituitary hyperplasia causing visual disturbance during adolescence. Case 1. A 15-year-old boy visited our department with a pituitary mass lesion on magnetic resonance imaging (MRI) associated with headache and transient bitemporal hemianopsia repeating. A visual field defect became apparent on the bitemporal upper side, and the area of the visual field defect enlarged to hemianopsia. The visual defect usually occurred in relation to exercise and continued for approximately 10 min. MRI showed the mass effect of pituitary hyperplasia to the optic chiasm. At six months later after the initial onset of the symptom, the visual field defect disappeared. Case 2. A 14-year-old girl came to our emergency department with a pituitary mass lesion on MRI associated with acute headache and visual disturbance occurring during exercise. MRI revealed the possibility of pituitary hyperplasia compressing the optic chiasm; however, her clinical course showed pituitary apoplexy. We conducted emergency transsphenoidal surgery to decompress her optic chiasm. The operative findings and histological examinations revealed a normal pituitary gland. Her visual disturbance immediately recovered after the surgery. Physiologic pituitary hyperplasia during adolescence can cause visual disturbance. Surgery should be carefully conducted, given the possibility of physiologic pituitary hyperplasia with visual symptoms.