隐睾症是男性生殖系统最常见的先天性畸形,约86%的正常男性睾丸在出生时下降正常,其余大多数在出生第一年下降。下降不全的睾丸易发展为恶性肿瘤,其恶变率比正常睾丸大39～50倍(1)。有关隐睾恶变之病例已有数篇报道(2、3)。本文报告5例.对其发病因素,诊断等问题结合文献进行讨论。临床病例资料见附表。 Cryptorchidism is the most common congenital malformation of the male reproductive system. About 86% of normal male testes are normal at birth, and most are declining in the first year of life. Poorly developed testes develop into malignant tumors with a malignant rate of 39-50 fold greater than normal testes (1). Several cases of malignant cryptorchidism have been reported (2,3). This article reports 5 cases of its incidence, diagnosis and other issues with the literature to discuss. Clinical case information see schedule.