The protrusion at the opening of the foreskin of the penis may be due to infection, condyloma acuminatum, cyst in the midline of the opening of the foreskin and other diseases. 1 infection: the opening position of the foreskin infection is the most common cause of local protrusion, after the infection of the local tissue edema may be protruding performance, the local can be accompanied by pain, redness and other symptoms. 2. acromegaly: acromegaly is a sexually transmitted disease, in the unclean sexual contact may be in the opening position of the foreskin warts growth and local protuberance, usually cauliflower-like growth. 3. circumcision midline cysts: circumcision opening midline position cysts can also lead to local protrusion, this situation is generally smooth surface, no obvious pressure pain, ultrasound examination can be clear. Overall, the opening of the foreskin has a protruding cause more, need to go to the regular public hospital urology department, check the specific reasons for targeted treatment.