A 35-year-old man is seen in the office due to heaviness in his lower abdomen. He has a history of bilateral cryptorchidism in childhood and underwent orchiopexy at age 14 months. The patient is otherwise healthy and takes no medications. Physical examination shows enlargement of both testicles. Scrotal ultrasound reveals bilateral testicular masses consistent with testicular germ cell tumor. CT scans of the chest, abdomen, and pelvis do not reveal any lymph node metastasis. The patient undergoes bilateral orchiectomy. Which of the following long-term physiologic changes are most likely to occur as a result of treatment in this patient?
Effects of androgen deprivation in men | |
Body composition |
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Skin, hair & breast |
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Skeletal |
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Genitourinary |
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Reproductive/sexual |
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This patient has undergone bilateral orchiectomy for testicular germ cell tumor. Bilateral orchiectomy is also performed for treatment of metastatic prostate cancer and as a component of gender-confirming surgery in transgender patients. With bilateral testicular loss or failure (eg, mumps orchitis), extragonadal androgen sources (eg, adrenals) are typically inadequate to replace the loss of testosterone, resulting in a hypogonadal state.
The prostate is dependent on the trophic effects of dihydrotestosterone (the primary active testosterone metabolite), which is derived from testosterone via 5-alpha-reductase activity in local tissues. Loss of the normal supply of testosterone leads to marked atrophy of the glandular component of the prostate. The effects on the prostate stroma are relatively less, but apoptosis may be seen in stromal cells, and the combined effect is a significant decrease in prostatic volume (Choice E). Other genitourinary and sexual effects of hypogonadism include erectile dysfunction, decreased ejaculate volume, and decreased libido.
(Choices A and C) Loss of testosterone leads to significant changes in body composition over time. Testosterone induces increased protein synthesis in myocytes, so hypogonadal patients typically experience a decrease in muscle mass/lean body weight. However, subcutaneous fat increases, and patients frequently experience a small net increase in total body weight.
(Choice D) Testosterone induces proliferation and differentiation of osteoblasts. If bilateral orchiectomy is performed after skeletal maturity, bone dimensions do not change, but trabecular bone density decreases (osteoporosis).
Educational objective:
Following bilateral orchiectomy, extragonadal androgen sources are inadequate to replace the loss of testosterone, causing a hypogonadal state. Loss of testosterone leads to changes in body composition, including decreased lean body weight, increased subcutaneous fat, and decreased bone density. Loss of testosterone also leads to a significant decrease in prostate volume.