睾丸下降与睾丸下降不全的已知和未知

The known and unknown about the testicular descent and undescended testes

胚胎期睾丸的发育需要经历下降过程，其机制复杂。睾丸下降不全（隐睾）是常见的小儿生殖系统异常，由于其涉及随后的生育及睾丸癌变等重要问题，与生殖、发育、内分泌及心理等多领域相关，有关睾丸下降机制及睾丸下降不全的病因、病理、诊断、治疗等多方面都一直处在不断地研究中。随着一些问题的已知，又带来相应的未知，或许这正在逐步接近事实的真相。现从已知和未知的角度简述目前的研究概况。

The mechanism of testicular descent in development of testis in embryonic period is very complex, and undescended testes（cryptorchidism） is a very common anomaly of the male genitalia. As it is close relatively with the later impaired fertility and cancer risk, involving reproduction, development, endocrinology and psychology, et al, the explorations of the mechanisms of testicular descent are continuing, and the studies on undescended testes such as the exact cause, pathogenesis, proper strategies for diagnosis and treatment are in progress. Along with some muddle becoming clear, the new puzzles often emerged. Perhaps this is getting closer to the truth. This paper is basically outlining the current research situation from the known and unknown aspects.