Box plots of inhibin-B (a) and FSH (b) serum levels, and bilateral testicular volume (c), in five groups of male patients according to testicular histology. Outliers are plotted individually. fSCO, focal Sertoli cell-only syndrome; cSCO, complete Sertoli cell-only syndrome. Serum inhibin-B in combination with serum FSH is a more sensitive marker than serum FSH alone for impaired spermatogenesis in men, but cannot predict with certainty the presence of sperm in testicular tissue samples (2) (Redrawn from von Eckardstein S, Simoni M, Bergmann M, Weinbauer GF, Gassner P, Schepers AG, et al. Serum inhibin B in combination with serum follicle-stimulating hormone (FSH) is a more sensitive marker than serum FSH alone for impaired spermatogenesis in men, but cannot predict the presence of sperm in testicular tissue samples. J Clin Endocrinol Metab, 1999; 84: 2496–501 (2).)