Table 1. Johnsen’s Scoring System for the Assessment of Testicular Biopsy Score (Johnsen, 1970)
Grade	Observed features
1	No germ cells or Sertoli cells in the tubular section
2	No germ cells, but Sertoli cells are present
3	Only spermatogonia are present
4	Only a few spermatocytes (<5), but no spermatids and spermatozoa are present
5	No spermatozoa or spermatids, but several or many spermatocytes are present
6	No spermatozoa and only a few spermatids (<5-10) present
7	No spermatozoa, but many spermatids present
8	Only a few spermatozoa (<5-10) are present
9	Many spermatozoa are present, but the germinal epithelium is disorganized
10	Complete spermatogenesis with many spermatozoa