One major challenge in male factor infertility is nonobstructive azoospermia (NOA), which is characterized by spermatozoa-deficient semen without physical duct blockage. This review offers a thorough overview of the histopathology of the testes in NOA cases, clarifying its complex etiology and emphasizing the possible value of histopathology inspection for both diagnosis and treatment. Variable histopathological findings have been linked to NOA, such as tubular hyalinization, Sertoli cell-only syndrome, hypospermatogenesis, and germ cell arrest. Understanding the pathophysiology and forecasting the effectiveness of treatment are further enhanced by both morphometric and ultrastructural analyses. The potential significance of testicular biopsy in forecasting reproductive outcomes is assessed, especially concerning assisted reproductive technologies like intracytoplasmic sperm injection (ICSI). Besides, testicular microlithiasis, serum hormone profiles, and testicular size are investigated concerning NOA histopathology. It is concluded that understanding the histopathological patterns in NOA is crucial for its accurate diagnosis and appropriate management. Further research is still warranted to improve understanding of the complex pathophysiology underlying NOA.
Humans ; Azoospermia/etiology* ; Male ; Testis/pathology* ; Sertoli Cell-Only Syndrome/pathology* ; Sperm Injections, Intracytoplasmic

Testicular histology based on testicular biopsy is an important factor for determining appropriate testicular sperm extraction surgery and predicting sperm retrieval outcomes in patients with azoospermia. Therefore, we developed a deep learning (DL) model to establish the associations between testicular grayscale ultrasound images and testicular histology. We retrospectively included two-dimensional testicular grayscale ultrasound from patients with azoospermia (353 men with 4357 images between July 2017 and December 2021 in The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China) to develop a DL model. We obtained testicular histology during conventional testicular sperm extraction. Our DL model was trained based on ultrasound images or fusion data (ultrasound images fused with the corresponding testicular volume) to distinguish spermatozoa presence in pathology (SPP) and spermatozoa absence in pathology (SAP) and to classify maturation arrest (MA) and Sertoli cell-only syndrome (SCOS) in patients with SAP. Areas under the receiver operating characteristic curve (AUCs), accuracy, sensitivity, and specificity were used to analyze model performance. DL based on images achieved an AUC of 0.922 (95% confidence interval [CI]: 0.908-0.935), a sensitivity of 80.9%, a specificity of 84.6%, and an accuracy of 83.5% in predicting SPP (including normal spermatogenesis and hypospermatogenesis) and SAP (including MA and SCOS). In the identification of SCOS and MA, DL on fusion data yielded better diagnostic performance with an AUC of 0.979 (95% CI: 0.969-0.989), a sensitivity of 89.7%, a specificity of 97.1%, and an accuracy of 92.1%. Our study provides a noninvasive method to predict testicular histology for patients with azoospermia, which would avoid unnecessary testicular biopsy.
Humans ; Male ; Azoospermia/diagnostic imaging* ; Deep Learning ; Testis/pathology* ; Retrospective Studies ; Adult ; Ultrasonography/methods* ; Sperm Retrieval ; Sertoli Cell-Only Syndrome/diagnostic imaging*

We performed this meta-analysis to evaluate the predictive value of different parameters in the sperm retrieval rate (SRR) of microdissection testicular sperm extraction (TESE) in patients with nonobstructive azoospermia (NOA). All relevant studies were searched in PubMed, Web of Science, EMBASE, Cochrane Library, and EBSCO. We chose three parameters to perform the meta-analysis: follicle-stimulating hormone (FSH), testicular volume, and testicular histopathological findings which included three patterns: hypospermatogenesis (HS), maturation arrest (MA), and Sertoli-cell-only syndrome (SCOS). If there was a threshold effect, only the area under the summary receiver operating characteristic curve (AUSROC) was calculated. Otherwise, the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and the diagnostic odds ratio (DOR) were also calculated. Twenty-one articles were included in our study finally. There was a threshold effect among studies investigating FSH and SCOS. The AUSROCs of FSH, testicular volume, HS, MA, and SCOS were 0.6119, 0.6389, 0.6758, 0.5535, and 0.2763, respectively. The DORs of testicular volume, HS, and MA were 1.98, 16.49, and 1.26, respectively. The sensitivities of them were 0.80, 0.30, and 0.27, while the specificities of them were 0.35, 0.98, and 0.76, respectively. The PLRs of them were 1.49, 10.63, and 1.15, respectively. And NLRs were 0.73, 0.72, and 0.95, respectively. All the investigated factors in our study had limited predictive value. However, the histopathological findings were helpful to some extent. Most patients with HS could get sperm by microdissection TESE.
Adult ; Azoospermia/therapy* ; Follicle Stimulating Hormone/blood* ; Humans ; Male ; Microdissection ; Oligospermia/pathology* ; Predictive Value of Tests ; Sensitivity and Specificity ; Sertoli Cell-Only Syndrome/pathology* ; Sperm Maturation ; Sperm Retrieval ; Spermatozoa ; Testis/pathology* ; Threshold Limit Values

OBJECTIVE: Azoospermia owing to testicular disorders is the most severe manifestation of male infertility. The main concern for patients with nonobstructive azoospermia (NOA) is the probability of successful sperm retrieval following testicular sperm extraction (TESE). Therefore, the goal of this study was to determine predictive factors correlated with sperm retrieval. METHODS: We assessed the testicular histopathological patterns, the choice of TESE surgical procedure, hormone levels, and chromosomal abnormalities in patients with NOA (n=170). The histopathology specimens were analyzed based on the histopathological patterns of hypospermatogenesis, maturation arrest, and Sertoli cell-only syndrome. RESULTS: The mean rate of sperm retrieval was 48.8%. The rate of sperm retrieval was significantly higher in the hypospermatogenesis group than in the other groups (p<0.001). There was a positive correlation between micro-TESE (vs. conventional TESE) and the sperm retrieval rate (odds ratio, 8.077; p<0.01). A logistic regression model demonstrated that high levels of follicle-stimulating hormone (FSH) and small testicular volume were significantly associated with lower chances of successful sperm retrieval. CONCLUSION: Some parameters, including testicular histopathology patterns, FSH levels, testicular volume, and method of TESE surgery, may be able to predict the chances of obtaining spermatozoa in patients with NOA. However, despite the efficiency of some predictive models, the hope of retrieving any functioning spermatozoa may be sufficient to disregard predictive factors of the success of intracytoplasmic sperm injection in these patients.
Azoospermia* ; Chromosome Aberrations ; Follicle Stimulating Hormone ; Hope ; Humans ; Infertility, Male ; Logistic Models ; Male ; Methods ; Oligospermia ; Pathology ; Sertoli Cell-Only Syndrome ; Sperm Injections, Intracytoplasmic ; Sperm Retrieval* ; Spermatozoa*