Morphological changes in the testicle in Sertoli cell-only syndrome in men with nonobstructive azoospermia

Abstract

BACKGROUND: The relevance of the morphological examination of testicular biopsies in infertile men is explained by limited information and research in this area, which is associated with limited indications for obtaining a lifetime biopsy in this nosology. The degree of pathological changes both in the Sertoli cells and testicular interstitium in the syndrome of “only Sertoli cells” (SCOS) is least studied. AIM: To evaluate morphological changes in SCOS. MATERIALS AND METHODS: Convoluted seminal tubules with SCOS were studied in nine men with nonobstructive azoospermia by staining sections with hematoxylin and eosin and toluidine blue, and light microscopy was used to study convoluted seminal tubules with SCOS in nine men with nonobstructive azoospermia. Moreover, the number of Sertoli cells, dystrophic changes in them, thickness of the convoluted seminal tubule, and number of mast cells in the testicular interstitium were counted. Correlation analysis of the relationships between variables was also performed. RESULTS: Mature Sertoli cells were found in 48.2% of convoluted seminal tubules, dystrophic Sertoli cells in 33.6%, and apoptotic Sertoli cells in 18.2%. The average number of Sertoli cells in one seminal tubule was 15.4 (min, 8.1; max, 19.2). The diameter of the convoluted seminal tubules averaged 33.8 (min, 23.0; max, 42.1) microns. The thickness of their shell at SCOS was on average 0.63 (min, 0.58; max, 0.69) microns. The number of mast cells in the testicular interstitium averaged 8.5±0.3 in 1 mm2. A strong and inverse (r=−0.87) correlation was established between the thickness of the shell of the convoluted seminal tubule and the number of Sertoli cells, and a strong and direct (r=0.83) correlation was found between the thickness of the shell of the convoluted seminal tubule and the number of mast cells in the interstitium of the testes. CONCLUSION: Among the studied cases, STCS is quite common in patients with nonobstructive azoospermia. The increased thickness of the shell of the convoluted seminal tubule contributes to the impaired architectonics of the hematotesticular barrier. This study revealed that mast cells exert direct effects on the wall thickness of the convoluted seminal tubule, which demonstrates the pathological effect of these cells on the permeability of the hematotesticular barrier and impaired spermatogenesis.