Histopathological mapping of open testicular biopsies in patients with unobstructive azoospermia

Objective To evaluate, in patients with unobstructive azoospermia, the hete rogeneity of spermatogenesis within the testes and thus whether there is an y region of advanced spermatogenesis. Patients and methods Seventy infertile men (mean age 34 years, SD 5.01) wit h no varicoceles or testicular atrophy had bilateral open testicular biopsi es taken from six different sites. For each biopsy specimen the number of s eminiferous tubules and of tubules with sperm maturation were counted (by l ight microscopy at x 400). The ratio of tubules with active spermatogenesis to the total number was calculated for each biopsy sample. Results The mean (so) right and left testicular volumes were 19.82 (7.8) an d 18.84 (7.89) mL, respectively; the patients' follicle-stimulating hormone level was 8.34 (1.17) IU/mL. On sextant biopsy spermatozoa were detected i n 42 of the 70 patients (60%). The mean (SD) ratio of tubules with spermato zoa was 5.23 (0.8)% for the right and 5.37 (0.76)% for the left testes. The re was no statistically significant difference in the ratio of seminiferous tubules positive for spermatozoa at the different biopsy sites in either t he right or left testis, Spermatozoa were identified in only one to three b iopsy sites in almost half of those with maturation arrest; this ratio incr eased to 74% in patients diagnosed as having Sertoli-cell-only syndrome wit h focal spermatogenesis. Conclusion There is no region of the testis that is rich or advanced in spe rmatogenesis in patients with unobstructive azoospermia. Without: multiple testicular biopsy it is possible to miss advanced spermatogenesis in some u nobstructed patients. The sextant testis biopsy is a reliable method for de tecting the presence and exact: location of seminiferous tubules with sperm atozoa in patients with unobstructive azoospermia.