PREVALENCE OF HYPOTHALAMIC-PITUITARY IMAGING ABNORMALITIES IN IMPOTENT MEN WITH SECONDARY HYPOGONADISM

Purpose: Because prevalence of structural lesions of the pituitary and hypothalamus in impotent men with secondary hypogonadism was undefine d, we evaluated 164 men 27 to 79 years old whose chief complaint was e rectile dysfunction and who repeatedly had low serum testosterone leve ls (less than 230 ng./dl.). Materials and Methods: With computerized t omography or magnetic resonance imaging of the sella we detected poten tially serious lesions (pituitary lesions greater than 5 mm. or any hy pothalamic lesion) in 11 men (6.7%, 95% confidence interval 2.9 to 10. 5%), including 5 pituitary microadenomas (5 mm. or larger), 4 pituitar y macroadenomas and 2 hypothalamic lesions. Results: Mean serum testos terone was lower in patients with (121 +/-: 66 ng./dl., standard devia tion) than without (177 +/- 39 ng./dl.) hypothalamic or pituitary imag ing abnormalities (p <0.001). For every 10 ng./dl. decrease in testost erone the risk of hypothalamic or pituitary imaging abnormalities incr eased 1.2-fold (p <0.005). Macroadenomas and hypothalamic lesions were confined to 6 subjects with testosterone levels of 104 ng./dl. or les s. Conclusions: The risk of hypothalamic or pituitary imaging abnormal ities is low among men evaluated for erectile dysfunction and secondar y hypogonadism. However, this risk increases markedly when the serum t estosterone level is markedly decreased.