Which pairing correctly matches a testosterone disorder with its typical cause?

• A. Primary hypergonadism — Testicular tumor
• B. Primary hypergonadism — Klinefelter syndrome
• C. Secondary hypergonadism — Precocious puberty
• D. Secondary hypogonadism — Kallmann syndrome

Answer: (A)

Understanding where excess testosterone comes from helps identify the correct pairing. In primary hypergonadism the gonads themselves overproduce testosterone, often due to an autonomous gonadal source such as a testicular tumor. A tumor in the testes can secrete testosterone directly, independent of pituitary signals, leading to elevated testosterone levels with feedback that suppresses LH and FSH. This makes a testicular tumor the classic cause of primary hypergonadism.

In contrast, Klinefelter syndrome stems from testicular dysfunction that reduces testosterone production (primary hypogonadism). Kallmann syndrome causes secondary hypogonadism through GnRH deficiency, leading to low gonadotropins and low testosterone. Precocious puberty, while it can raise testosterone via early activation of the hypothalamic-pituitary-gonadal axis (secondary hypergonadism), is not the most straightforward example when matching a testosterone disorder to its typical cause. Therefore, the pairing with a testicular tumor causing primary hypergonadism best fits.