The cytologic identification and quantification of testicular cell subtypes. Reproducibility and relation to histologic findings in the diagnosis of male infertility.

In testicular imprint smears from 100 infertile men (both testicles), stained using the Pappenheim and Papanicolaou methods, the cell forms (light and dark spermatogonia, primary and secondary spermatocytes, spermatids, spermatozoa and Sertoli cells) were identified and quantified by the counting of 500 consecutive cells. Identification of the cell types, which are described and illustrated, was consistent and reproducible; the advantages of the different stainings in their analysis is documented. The cell counts were tested for reproducibility and compared to the histologic diagnoses and sperm counts. Statistical analysis showed the highest reproducibility for cells frequently encountered in smears (0.99 for Sertoli cells and 0.98 for spermatozoa) and the lowest but still satisfactory reproducibility for rare or arbitrarily defined cell forms (0.71 for dark spermatogonia and 0.76 for secondary spermatocytes). The high reproducibility of the smear quantification permits the introduction of a number of indices, defining clinically useful relations between cell types that are indicative of various types of infertility. The data obtained by cytologic quantification showed reasonably good correlation with the histologic diagnoses of desquamation and focal fibrosis and excellent correlation with Sertoli cells only, arrested spermatogenesis and complete fibrosis. The cytologic quantification of testicular smears adds considerable information to the diagnosis of impaired fertility and should be instituted in properly equipped centers.