Diffuse infiltration of urethra is one of the symptoms of urethral cancer. Urethral cancer belongs to urethral epithelial tumor, which is relatively rare in clinical practice. Urethral cancer is very harmful, so it is very important to understand the symptoms and examination of urethral cancer. First of all, the age of onset of urethral cancer is from 13 to 91 years old, and most of them are over 50 years old. Patients usually seek medical treatment with symptoms of urethral obstruction, swelling, periurethral abscess, urinary extravasation, urethral fistula and urethral discharge, etc. Some patients have symptoms of pain, hematuria or hematospermia. Tumors of the navicular fossa may present as ulcers or papillary lesions. Rectal bimanual examination can reveal whether the tumor has extended to the prostate, anus and urogenital diaphragm. The incubation period of urothelial cancer is 10-20 days. The onset of the disease is not as urgent as gonorrhea, and the symptoms are delayed, sometimes mild and sometimes severe, but lighter than gonorrhea. About 50% of patients have symptoms such as painful urination and itchy urethra. It is easy to be missed at the initial diagnosis. Clinical staging is based on clinical and pathologic biopsy findings and is reviewed based on pathologic findings in surgical specimens. stage O, confined to the mucosa (carcinoma in situ), stage A, lesions to the submucosa, stage B, lesions invading the urethral corpus cavernosum, stage C, direct extension to extra-urethral corpus cavernosum tissue or beyond the prostatic envelope, stage D1, regional metastases including inguinal/pelvic lymph nodes (primary tumor can be any stage), stage D2. distant metastases (primary tumor can be of any stage). Second, the urethral discharge is scanty, thin, mucinous or mucopurulent. A small amount of thin discharge from the external urethral orifice may occur after a longer period of time without urination (e.g., in the morning). Sometimes it only shows up as morning scabs sealing the urethral orifice or contaminating the underwear. On examination, it is necessary to press the anterior urethra from back to front before a small amount of discharge may escape from the urethral orifice. Sometimes the patient may have symptoms without discharge, or may have discharge without symptoms. The onset of the disease is 1-3 weeks after infection. It is easily mistaken for untreated gonorrhea or recurrence in clinical practice.