Purpose: An attempt to make a rational strategy for treatment of cryptorchidism.
Materials and Methods: 1,335 cryptorchid boys with biopsy at surgery (1,638 specimens).
We studied: frequency of no germ cells in biopsies from 698 patients <12 years at
surgery; fertility potential of 140 patients who were now adults, and apperance of
testicular neoplasia in all biopsies. Results: Lack of germ cells appeared from
18 months. The frequency increased with increasing age. It appeared in 30% (61/202)
bilateral, and 18% (88/496) unilateral cases. In men who had undergone bilateral or
unilateral orchiopexy, respectively, there was normal sperm count in 19% (14/75) and
83% (54/65), and infertility was suspected in 56% (42/75) and 8% (5/65) (FE, p < 0.00005,
p < 0.00005), respectively. The lowest, the mean, and the highest age-matched spermatogonia
count per tubule at orchiopexy was associated with sperm count (Spearman test, p <
0.0001, p < 0.005, p < 0.05). Isolated, this was demonstrated for the 75 formerly
bilateral (Spearman, p < 0.0001, p < 0.0001, p < 0.0001), but not the 65 formerly
unilateral cases (Spearman, p = 1.0). No germ cells at orchiopexy was associated with
suspected infertility. Risk was 78–100% in bilateral (dependent on one or both testes
affected), and 33% in unilateral cryptorchidism. There was one invasive germ cell
tumor, six cases of carcinoma in situ testis, and one Sertoli cell tumor. Three neoplasms
were diagnosed in intra-abdominal testes, four in boys with abnormal external genitalia,
and two in boys with known abnormal karyotype. Risk of neoplasia was 5% (7/150) in
patients with intra-abdominal testis, abnormal external genitalia or diagnosed abnormal
karyotype, versus 0% (0/1,185) in patients without these characteristics (FE, p <
0.00005). Conclusion: We recommend surgery for cryptorchidism before 15–18 months
of age because: (a) lack of germ cells is very rare before, and (b) lack of germ cells
is associated with subsequent risk of infertility. At primary surgery for cryptorchidism,
we recommend examination for testicular neoplasia in cases of intra-abdominal testis,
abnormal external genitalia or known abnormal karyotype.