Part of “CHAPTER 115 – MALE HYPOGONADISM“

The clinical presentation of hypogonadism depends on whether the onset was in utero, prepubertal, or postpubertal. If hypogonadism is present because of a defect that occurred in utero, the individual will have ambiguous genitalia (see Chap. 77 and Chap. 90). The clinical pictures of testicular androgen failure of prepubertal and postpubertal onset are presented in Table 115-2.

Although the findings on physical examination may be normal, a problem with seminiferous tubule function may manifest
as infertility. With the development of sensitive assays for testosterone, an increasing number of circumstances have been described in which serum testosterone levels are lower than normal without any obvious end-organ deficiencies. Examples of this phenomenon are seen in aging or stressed men who have low levels of serum testosterone without definitive evidence of end-organ deficiency. In the case of stress, end-organ deficiency may not be seen, because the period of hypogonadism is transient. Deciding whether these men really are androgen deficient or whether they simply are displaying a physiologic response to stress or age may be difficult. These situations pose further difficulties for clinicians who must decide whether androgen replacement is needed. The classic states of androgen deficiency are discussed in this chapter; androgen replacement therapy, described in Chapter 119, is mentioned. In those situations in which obvious deficiency states are not present, however, the indication for replacement therapy may not be clear-cut. In some of these patients, the finding of an exaggerated gonadotropin response to luteinizing hormone–releasing hormone (LHRH) may help to define the presence of testicular failure.