Cryptorchidism

1 Introduction.- 2 History and Evolution of Testicular Descent.- 2.1 History of Research into Testicular Descent and Maldescent.- 2.2 Evolution of Testicular Descent.- References.- Implications.- 3 Embryology of Testicular Descent and Maldescent.- 3.1 Indifferent Stage of Gonadal Development.- 3.2 Differentiation of the Testis.- 3.2.1 Germ Cells.- 3.2.2 Sertoli Cells.- 3.2.3 Leydig Cells.- 3.3 Male Duct Differentiation and Development.- 3.3.1 Development of the Testis Coverings.- 3.3.2 Comparison of Testicular Descent in Humans and Rodents.- 3.4 Estrogen-Induced Cryptorchidism.- 3.5 Spondaneous Congenital Cryptorchidism in Mice: Treatment with GnRH.- 3.6 Morphology and Histology of the Cryptorchid Epididymis.- References.- 4 Histology and Ultrastructure of Normal and Cryptorchid Testes.- 4.1 Development of the Normal Testis in Children.- 4.1.1 First Year of Life.- 4.1.2 Fourth Year.- 4.1.3 Puberty.- 4.2 Development of the Cryptorchid Testis.- 4.2.1 Behavior of the Number of Spermatogonia in Cryptorchid Gonads.- 4.2.1.1 In Relation to Age.- 4.2.1.2 In Relation to Position.- 4.2.2 Ultrastructure of Cryptorchid Testis.- 4.2.2.1 Germ Cells.- 4.2.2.2 Sertoli Cells.- 4.2.2.3 Peritubular Connective Tissue.- 4.2.2.4 Leydig Cells.- 4.2.3 Congenital or Acquired Lesions? Iatrogenic Cryptorchidism.- 4.2.4 Frequency and Ultrastructure of Carcinoma In Situ Cells in the Testes of Cryptorchid Children.- References.- 5 Endocrinology of the Hypothalamo-Pituitary-Gonadal Axis.- 5.1 Development of the Hypothalamo-Pituitary-Gonadal Axis During Intrauterine Life in Normal Males.- 5.2 Development of the Hypothalamo-Pituitary-Gonadal Axis in Normal Boys.- 5.3 Role of Leydig Cells.- 5.4 Mechanism of Androgen Action.- 5.5 Role of Sertoli Cells.- 5.6 Testing of the Hypothalamo-Pituitary-Gonadal Axis Utilizing GnRH.- 5.7 Development of the Hypothalamo-Pituitary-Gonadal Axis in Cryptorchid Boys.- References.- 6 Fertility in Cryptorchidism.- 6.1 Introduction.- 6.2 Factors Influencing the Interpretation of Infertility Data in Cryptorchid Patients.- 6.2.1 Patient Source.- 6.2.2 Age at Treatment.- 6.2.3 Medical VS Surgical Treatment.- 6.2.4 Location of Testis.- 6.2.5 Injury from Surgery.- 6.2.6 Method of Sperm Analysis.- 6.2.7 Definition of Infertility.- 6.3 Analysis of Extant Fertility Data.- 6.4 Special Considerations Regarding Fertility in Cryptoridism.- 6.5 Correlation of HCG-Induced Descent and Subsequent Fertility.- 6.6 Fertility in Cryptorchid Patients with Compensatory Testicular Hypertrophy.- 6.7 Evidence for a Contralateral Lesion in the Descended Testis.- References.- 7 Cryptorchidism and Malignant Testicular Disease.- 7.1 Etiologic Theories of Malignant Degeneration.- 7.2 General Risk Factors in Testicular Cancer.- 7.3 Premalignant Histologic Changes in the Cryptorchid Gonad.- 7.4 Tumor Cell Types in Undescended Testes.- 7.5 Incidence and Risk Analysis of Malignant Disease with Cryptorchidism.- 7.6 Theoretical Considerations.- References.- Treatment.- 8 Examinations and Clinical Findings in Cryptorchid Boys.- 8.1 Incidence.- 8.2 Position and Side Affected.- 8.3 Concomitant Findings.- 8.3.1 Mental and Somatic Retardation.- 8.3.2 Heredity.- 8.3.3 Torsion of Testis.- 8.3.4 Hernias, Renal Failure, and Genital Malformations.- 8.3.5 Psychic Alterations.- 8.4 Examination Technique.- References.- 9 Indications and Contraindications for Orchiopexy.- 9.1 Perform Orchiopexy.- 9.2 Perform Orchiectomy.- 9.3 Omit Surgical Treatment.- References.- 10 Hormonal Treatment.- 10.1 HCG Treatment.- 10.2 GnRH Treatment.- References.- 11 Surgical Treatment of Cryptorchidism.- 11.1 Introduction.- 11.2 Preoperative Localization of the Testis.- 11.3 Surgical Techniques.- 11.3.1 Standard Orchiopexy.- 11.3.2 Staged Orchiopexy.- 11.3.3 Fowler-Stephens (Long-Loop Vas) Orchiopexy.- 11.3.4 Microsurgical (Autotransplantation) Technique.- 11.3.5 Neonatal Transabdominal Orchiopexy.- References.- 12 Conclusions.- 12.1 The Role of the Epididymis in Testicular Descent.- 12.2 Clinical and Pathophysiological Implications in Cryptorchid Boys.- 13 Treatment Schedule.- 14 Prospectives.- References.