Cryptorchidism, testicular atrophy and reduced fertility
- Lesion
A testis that stays undescended loses its germ cells and carries a higher risk of cancer; many other causes shrink the testis too.
What it is
Cryptorchidism is failure of the testis to descend into the scrotum, found in a few percent of term boys and more preterm ones; most descend in the first months. Descent has a transabdominal phase controlled by INSL3 and a hormone-dependent inguinoscrotal phase. A testis left undescended undergoes progressive atrophy and germ cell loss from about the second year, causing infertility and raising the risk of germ cell tumours in both testes. Other causes of atrophy include ischemia, orchitis, hypopituitarism, chemotherapy and radiation, cirrhosis and estrogen excess, and Klinefelter syndrome.
Structure
- The cryptorchid testis is small and firm from fibrosis.
- Tubules show Sertoli cells only, with absent spermatogenesis and thickened, hyalinized basement membranes.
- Germ cell neoplasia in situ may be found in biopsies.
Causes of testicular atrophy and reduced fertility
| Cause | Mechanism | Clue |
|---|---|---|
| Cryptorchidism | Heat and maldevelopment destroy germ cells | Empty scrotum since birth |
| Varicocele | Venous congestion raises scrotal temperature | Bag of worms, usually left side |
| Klinefelter syndrome | 47,XXY; failure of tubules | Small firm testes, gynecomastia, tall stature |
| Mumps orchitis | Viral inflammation after puberty | Painful swelling with or after parotitis |
| Hormonal and toxic causes | Low gonadotropins, estrogens, chemotherapy, radiation, cirrhosis | Systemic disease or treatment history |
Clinical notes
- Infants with an undescended testis beyond six months are referred for surgery.
- Male infertility is investigated with semen analysis; testicular biopsy shows the pattern of failure.
Test yourself
Think of the answer, then tap the question to see it.
When does atrophy begin in an undescended testis?
From around the second year of life, which is why early orchiopexy is advised.
Does orchiopexy remove the cancer risk?
No. It lowers atrophy and allows examination, but the risk of germ cell tumour remains higher, even in the other testis.
What are three acquired causes of testicular atrophy?
Mumps orchitis, varicocele and estrogen excess (for example in cirrhosis); chemotherapy and radiation also.
Elsewhere in DurgiPedia
- Cryptorchidism
- Gonads and the descent of the testis
- Atrophy
- Sex chromosome disorders: Klinefelter and Turner
- Testis: seminiferous tubules, Sertoli and Leydig cells, spermatogenesis
Connections
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Cryptorchidism (StatPearls (NCBI Bookshelf), 2024).
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Representative model, for educational purposes only.