1.What does occult penis mean? There is no consensus on the title and classification of occult penis at home and abroad. Usually, it is defined as that occult penis is a congenital disease, and clinically it should only mean that the penis is hidden in the subcutaneous soft tissue in front of the pubic bone, and the appearance of the penis is seen to be short, and the development of the penile corpus cavernosum is still normal. It is also called true concealed penis, or congenital concealed penis. The epidemiological survey of male adolescent external genital diseases in Hefei area found that the incidence of occult penis is 0.68%, which is second only to prepuce and circumcision among penis-related developmental problems. 2. How does occult penis occur? The pathogenesis of occult penis is not fully understood. Regarding its etiology, the following views are generally accepted: ① The penile skin is not attached to the penile body. The distal end of the urogenital sinus, which normally extends to the genital node during embryonic stage, is underdeveloped, and the penile skin fails to attach to the penile body normally, and attaches directly to the front end or even the neck of the penile body, resulting in the penis not being able to effectively stimulate the normal development of the penile skin during penile development, the shortage of penile skin and the narrow circumcision cavity, and the penile body not being able to enter the penile skin and the circumcision cavity normally; ② poor development of the penile meatus membrane. Normal sarcolemma has strong elasticity and is loosely attached to the penile skin and its deep surface penile fascia (Buck fascia), and the penis body can slide freely under the skin. If the sarcolemma is not well developed, the sarcolemma shortens and thickens, forming inelastic fibrous cords that will restrict the extension of the penis, pulling the penile body proximally and constraining it at the pubic mons below the pubic symphysis; (3) pulling the subcutaneous fascia of the abdominal wall and its surrounding fatty tissue distally (the fatty layer of the abdominal wall shifts downward), and the excessive prepubic fatty tissue aggravates the appearance of occlusion. According to the different pathological changes of occult penis, it can be divided into three types, namely, corded type: the presence of obvious stripes on the dorsal side of the penile body; circumcised type: the prepuce opening is obviously narrow and the narrow opening is close to the root of the penis, and there is a severe shortage of penile skin; obese type: the body type is obese, there is excessive fat accumulation in front of the pubic bone, and the penile skin is separated from the penile body. 3. How to identify occult penis clinically? Children with occult penis clinically mainly show the following five features: ① short penile appearance, short distance between the prepuce opening and the penile root, and the prepuce wrapping the penis in a bird’s beak-like or pipe shape; ② penile skin and prepuce cavity are empty, and penile skin is not normally attached to the penile body, so that the penile skin is short dorsally and long ventrally, with more inner plates and less outer plates; ③ pushing back the skin around the penis can show a normal-sized penis; ④ sometimes in (4) sometimes obvious fibrous strips are palpated on the dorsal side of the penis; (5) often accompanied by prepuce. Further examination is to pull the head of the child’s penis and push back the skin around the root of the penis to reveal a normally developed penis, pull the head of the penis and then release it to observe the retraction of the penis. If the penis sticks out of the foreskin when pulling, and the penis retracts quickly after releasing, it can be identified as occult penis. In addition, other penile deformities should be excluded, such as normal-looking prepuce with a small prepuce opening that prevents the head of the penis from being exposed; small penile body, which is more than 2.5 times the standard deviation smaller than normal, often combined with endocrine defects or chromosomal abnormalities; or secondary occult penis caused by syringomyelia, inguinal hernia, etc., as well as obese children due to the accumulation of fat in the lower abdomen, especially in front of the pubic bone. 4.What are the hazards of occult penis to men’s health? (1) The prepuce opening of occult penis is narrow and the foreskin cannot retract, which may prevent the normal development of the penis head or even the whole penis. (2) Children’s sexual psychology begins to form at the age of 2. The short appearance of the penis and abnormal urination do not want to be seen by others, which may cause psychological developmental disorders in the affected children. (3) Because the occult penis cannot be extended. It is difficult to hold the penis when urinating, and it is easy to wet pants; the narrow ring leads to difficulties in cleaning the foreskin penis of the affected child, repeated foreskin infections, and even difficulty in urination may occur. (4) Long-term concealed penis may affect sexual life in adulthood, such as erectile dysfunction, painful penile erection, difficulty in sexual intercourse and psychosexual disorder. 5. Does concealed penis need surgery? What is the age of surgery? There has been disagreement on whether occult penis needs to be treated and the timing of surgery. The general principle of treatment is to choose the treatment according to the cause and main clinicopathological features, which mainly includes observation and waiting and surgical correction. Some physicians suggest that surgery can be considered in early childhood (2 to 3 years of age) when standing and urination begins, others believe that surgery should be considered before school age, while others believe that the decision can wait until adolescence based on clinical findings that a significant proportion of children with anaphylaxis heal spontaneously with age and that the development of the penile body is not greatly affected by not having surgery early in life. The current tendency is to agree that for children with anaphylaxis who are obese and do not have other lesions such as prepuce, they can be treated by weight loss and upward pushing foreskin cleaning due to poor surgical results or postoperative complications. After the age of 12 to 14, the majority of children with anaphylaxis will have faster penile development and greater changes in penile appearance as the androgen level in children’s bodies gradually increases with age. After 12 years old, if there is still no obvious improvement, surgery can be performed to correct the problem. For the corded and circumcised anaphylactic penis, which usually cannot heal on its own, it is advisable to operate as early as possible before school age to avoid the possible psychological impact on the child. Surgery can also be performed at any age for those who are diagnosed late. There are many surgical methods to correct anaplasia, but the following must be achieved: (1) completely remove the fibrous cords that bind the penis to stretch and have enough foreskin to cover the penile body; (2) fix the penile skin and fascia on the straightened penis to prevent retraction; (3) adequately cut the circumcision stenosis ring, but traditional circumcision is contraindicated.