Why do men with prolactin secreting tumors often present with more advanced disease compared with women?
The major symptoms of elevated prolactin values in men are decreased libido and impotence. These symptoms may be ignored or attributed to psychological causes. Many years may go by before an evaluation is sought, often when the patient experiences headaches and visual field defects related to the mass effect of the enlarging tumor. Women are more likely to seek evaluation early in the disease process, when infertility or menstrual irregularities prompt an evaluation of their hormonal status. Interestingly, studies have suggested that large (≥ 10 mm) and small (< 10 mm) tumors may be biologically different at their onset. There appears to be no difference in the prevalence of large tumors between men and women; however, there is a much higher prevalence of small tumors in women. This difference suggests that factors in women, possibly estrogen, may promote the appearance of prolactin-secreting tumors, but when these appear, they may be smaller and less aggressive.