A reproductive endocrinology clinic is evaluating four male patients for primary infertility. Each patient has confirmed azoospermia on semen analysis but presents with a distinct endocrine laboratory profile and specific physical examination findings. Match the following clinical and laboratory profiles with their most likely underlying etiology.
- Azoospermia, decreased serum FSH and LH, decreased serum testosterone, anosmiaKallmann syndrome
- Azoospermia, elevated serum FSH and LH, decreased serum testosterone, small firm testesKlinefelter syndrome
- Azoospermia, normal serum FSH and LH, normal serum testosterone, nonpalpable vas deferensCystic fibrosis
- Azoospermia, decreased serum FSH and LH, elevated serum testosterone, muscular hypertrophy and testicular atrophyExogenous anabolic steroid use
Answer
The profile with low FSH/LH, low testosterone, and anosmia matches Kallmann syndrome. The profile with high FSH/LH, low testosterone, and small testes matches Klinefelter syndrome. The profile with normal labs and nonpalpable vas deferens matches Cystic fibrosis. The profile with low FSH/LH, high testosterone, and testicular atrophy matches Exogenous anabolic steroid use.
Kallmann syndrome presents with hypogonadotropic hypogonadism and anosmia due to failed neuronal migration. Klinefelter syndrome presents with hypergonadotropic hypogonadism and small firm testes due to primary gonadal failure. CFTR mutations cause obstructive azoospermia with normal endocrine labs. Exogenous steroids suppress gonadotropins while maintaining high systemic androgens, leading to testicular atrophy.
Step-by-Step Solution
Key Concept
Male factor infertility workup requires distinguishing between pre-testicular (hypogonadotropic), testicular (hypergonadotropic), and post-testicular (obstructive) etiologies using FSH, LH, and testosterone levels in conjunction with physical examination.