Reactive pituitary abnormalities in patients with Klinefelter's and Turner's syndromes.

Ten unselected patients with gonadal dysgenesis, three with Klinefelter's and seven with Turner's syndromes, were studied. Two of the patients with Klinefelter's and two with Turner's syndromes had enlarged pituitary fossae. The other six patients had normal sized sella, but showed localized change in the sellar contour on polytomography, suggesting hyperplasia or microadenoma formation of the pituitary gland. All ten patients had abnormally high serum follicle-stimulating hormone levels both at basal and after luteinizing hormone-releasing hormone stimulation. These results suggest that hyperplasia or microadenoma of the pituitary gland may occur secondary to gonadal failure, producing enlarged volume or attenuation in the normal contour of the sella turcica. Lack of awareness of reactive pituitary changes secondary to gonadal failure may result in inappropriate surgical management of what may appear to be primary pituitary tumor.