Question 1 · Hard
A 29-year-old bodybuilder is referred because he and his wife have not conceived after 2 years. His puberty was normal at 13, his sense of smell is normal and he has acne. His testes are small and soft. Results: total testosterone 2.8 nmol/L (81 ng/dL; reference 8.6-29), LH < 0.2 IU/L (reference 1.7-8.6), FSH < 0.2 IU/L (reference 1.5-12.4), prolactin 9 µg/L (reference < 15), hematocrit 0.55 L/L (reference 0.40-0.50) and HDL cholesterol 0.6 mmol/L (23 mg/dL). Semen analysis shows no sperm. The most likely explanation is:
- AUse of a non-testosterone anabolic steroid
- BCongenital GnRH deficiency (Kallmann)
- CPrimary failure of the testes
- DA prolactin-secreting pituitary adenoma
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Answer: A · Use of a non-testosterone anabolic steroid
Low testosterone with undetectable LH and FSH is hypogonadotropic hypogonadism, so the problem lies above the testes. Normal puberty and a normal sense of smell exclude congenital GnRH deficiency, and a normal prolactin argues against a prolactinoma. The high hematocrit, low HDL and acne show strong androgen action despite a low measured testosterone, which fits a synthetic anabolic steroid such as nandrolone or stanozolol. These drugs suppress LH and FSH, so the testes stop making testosterone and sperm, but testosterone assays largely do not measure the drug itself. Primary testicular failure would raise LH and FSH, and mass spectrometry of urine can confirm anabolic steroid use.
- B: Normal puberty and a normal sense of smell exclude congenital GnRH deficiency.
- C: Primary testicular failure raises LH and FSH; here they are suppressed.
- D: Prolactin is normal, so a prolactinoma is unlikely.