Bladder squamous cell carcinoma

　　1. Causes of onset

　　Chronic urinary tract infection is the main cause of bladder squamous cell carcinoma. In the urine of 90% to 93% of patients with bladder squamous cell carcinoma, there can be a long-term presence of pus cells and leukocytes. Chronic inflammation stimulation can lead to metaplasia of transitional epithelium into squamous cells, intercellular change, and carcinoma. Some believe that after infection, certain bacteria convert nitrates into nitrites and nitrosamines with carcinogenic effects, which can then lead to the formation of tumors. Stimulation by bladder stones, catheters, and other foreign bodies is also an important cause of squamous cell carcinoma. The incidence of bladder stones with squamous cell carcinoma ranges from 0.074% to 9.9% (Sarma, 1970; Bessette, 1974), while the incidence of squamous cell carcinoma with stones is as high as 2.77% to 47% (Zhu Liangchun, 1980; Zhang Sixin, 1987). Long-term stimulation by stones can cause tissue cell proliferation and carcinoma. Chronic stimulation by catheters can also lead to the occurrence of tumors. Kaufman (1977) reported that among 62 patients with spinal cord injury, 80% of those with catheters inserted for more than 10 years had bladder squamous metaplasia, 42% of those with catheters inserted for 6 to 10 years had bladder squamous metaplasia, and only 20% of those without catheters had bladder squamous metaplasia. Among the 25 patients with catheters inserted for more than 10 years, 5 developed squamous cell carcinoma, and they also had diffuse inflammation, squamous epithelial metaplasia, and bladder in situ carcinoma. This indicates that chronic bladder inflammation, stones, foreign bodies, and other factors are interrelated and often coexist, and can all lead to squamous metaplasia of transitional bladder epithelium, intercellular change, atypical hyperplasia, and lead to carcinoma. In Egypt, Africa, and the Middle East, where schistosomiasis is prevalent, 70% of bladder walls in bladder cancer cases can be found to contain schistosome eggs, and it is believed that schistosomiasis infection is one of the causes of bladder squamous cell carcinoma. However, the carcinogenic mechanism is not yet clear. Some lesions such as leukoplakia of bladder mucosa can further develop into tumors under certain factors.

　　2. Pathogenesis

　　Squamous cell carcinoma of the bladder often appears as flat or slightly elevated, with infiltrative growth, presenting as solid masses, ulcerative or papillary. It is usually solitary, but can also be multiple. Pathological examination shows pure squamous cell carcinoma in most cases, and mixed carcinomas with components such as transitional cell carcinoma and adenocarcinoma account for about 1/3. The histological characteristics include the appearance of keratinocytes, large squamous cell masses arranged in irregular sheets, with concentrically arranged keratinocytes - keratin pearls. According to the degree of squamous cell differentiation, it can be divided into IV grades: Grade I: highly differentiated cells, very similar to normal or metaplastic squamous epithelial cells, with keratin pearls formation, and mild nucleolar abnormalities; Grade II: solid growth of the tumor, with extensive keratinization and keratin pearl formation; Grade III: keratin is limited to individual cells and occasionally keratin pearls; Grade IV: large clear cells, rare poorly differentiated squamous cells. Small cell type squamous cell carcinoma has very poor differentiation, similar to the oat cell carcinoma of the lung, with typical squamous cell carcinoma pearls. Squamous cell carcinoma caused by schistosomiasis often shows giant cells with two nuclei.

　　Complications that may occur in urethral cancer include:

　　1. Obstructing the urethra, caused by the shedding of cancer masses leading to urinary tract obstruction and difficulty in urination, but urinary retention rarely occurs.

　　2. Infection, which can penetrate through the urethral海绵体, causing perineal urethritis, or leading to perineal urethral abscess. Pathogens can infect the ureter and kidneys through ascending motion; or spread to the scrotum and perineum, causing perineal urethral fistula. Other complications may include urinary tract tumors with skin metastasis, etc.

　　Hematuria and bladder irritation symptoms, about 80% appear hematuria, mainly with gross hematuria throughout the urine, and about 70% of those with bladder irritation symptoms mainly have dysuria. The characteristics are severe symptoms that cannot be relieved by medication, and the incidence of difficulty in urination and urinary obstruction is also more common than that of transitional cell carcinoma.

　　The prevention of bladder cancer has 5 aspects:

　　1. Take preventive measures against the cause, such as the confirmation that certain occupations such as dye, rubber, and leather can cause bladder cancer, smoking, and taking certain drugs can significantly increase the incidence of bladder cancer. This requires improving the production conditions of industries such as dyes, rubbers, and leathers, advocating the ban on smoking, and avoiding the long-term use of drugs that can cause bladder cancer.

　　2. Pay high attention to the close follow-up of patients with hematuria, especially for male patients over 40 years old with hematuria of unknown cause. In principle, strict and formal diagnostic examinations should be adopted, including cystoscopy, for screening bladder cancer.

　　3. Carry out mass screening work, especially for high-risk populations.

　　4. Strengthen basic and clinical research work, including improving the accuracy of non-invasive examinations for early diagnosis of bladder cancer and developing drugs to prevent the recurrence of bladder cancer.

　　Promote the education of tumors, popularize relevant medical knowledge, improve the public's understanding of urinary system tumors, make them seriously participate in regular physical examinations, establish an early consultation awareness, which is conducive to the early diagnosis of bladder tumors.

　　1. Urinalysis shows positive occult blood.

　　2. The positive rate of urinary cytology for bladder squamous cell carcinoma is higher than that for transitional cell carcinoma.

　　3. Cystoscopy can clearly determine the location, number, and size of the tumor, which often appears as nodular, ulcerative, cauliflower-like, or broad-based papillary, with an irregular surface, which may have bleeding, necrosis, and surrounding inflammatory manifestations such as congestion and edema. When stones are present, there may be plaque-like elevations or ulcers in the bladder wall in the stone area.

　　4. IVU can show bladder filling defects and understand the condition of the upper urinary tract, which is helpful for clinical staging.

　　5. Ultrasound scanning shows a solid mass in the bladder with inhomogeneous echo, and the boundary is unclear.

　　The diet should mainly consist of light foods, pay attention to dietary regularity. Or eat a reasonable diet according to the doctor's advice. The diet of patients should be light and easy to digest, eat more vegetables and fruits, reasonably match the diet, and pay attention to sufficient nutrition. In addition, patients need to pay attention to avoid spicy, greasy, and cold foods.

　　I. Treatment

　　1. Mixed bladder squamous cell carcinoma, radiotherapy or chemotherapy can be combined with surgery according to the histological type of the mixed carcinoma and the proportion of various tissues, and the prognosis is better than that of pure squamous cell carcinoma.

　　2. The histology of squamous cell carcinoma often shows a deeper and wider infiltration range than expected, so partial cystectomy of the bladder often fails to achieve the expected goal. Radical cystectomy and extensive complete resection of the urachal tumor are the only treatment options. Radiotherapy and chemotherapy are ineffective. The tumor often metastasizes to the iliac fossa, inguinal region, omentum, liver, lung, and bones. Therefore, treatment must be very aggressive. Transurethral resection, partial cystectomy, or radiotherapy are difficult to be effective. Preoperative radiotherapy (or not) and radical cystectomy are the preferred treatment options. Chemotherapy regimens used for transitional cell carcinoma are ineffective for squamous cell carcinoma. The recurrence rate of this disease in the urethra is relatively high (50%), so urethral resection should be performed during total cystectomy.

　　II. Prognosis

　　The prognosis of this disease is poor, with a 5-year survival rate of about 20%.