Bladder tumors have the highest incidence rate, but they are not as dangerous as lung cancer, liver cancer, pancreatic cancer, etc. Moreover, some of them are benign lesions, so the correct differentiation between benign and malignant bladder tumors is a matter of life and death. This is because there is a huge difference in treatment, prognosis and survival time between benign and malignant tumors.
I. Differences between benign and malignant bladder tumors
1. Name
The term “cancer” usually refers to all malignant tumors, but strictly speaking, “cancer” refers to malignant tumors that originate from epithelial tissues, which is the most common type of malignant tumors, such as bladder cancer, kidney cancer, prostate cancer, etc. Some malignant tumors that originate from mesenchymal tissues are collectively referred to as “cancer. Some malignant tumors originated from mesenchymal tissues are collectively called “sarcoma”. However, there are a few malignant tumors not named according to the above principle, such as nephroblastoma, malignant teratoma, etc.
2. Characteristics
Features of benign “bladder tumor”.
(1) Growth pattern: Benign tumor refers to the abnormal proliferation of cells in certain tissues in the body, which shows swelling or exophytic growth, like ballooning with gradual expansion and relatively slow growth.
(2) Character, boundary and envelope: Because the tumor body keeps increasing, it can squeeze the surrounding tissues, but does not invade the adjacent normal tissues.
(3) Texture and color: The texture and color are close to normal tissues.
(4) Invasiveness: generally non-invasive, with a few local invasions.
(5) Metastatic: no metastasis.
(6) Recurrence: complete excision, with few recurrences.
(7) Hazards: the organism is maturely differentiated and less harmful to the organism.
Malignant “bladder tumor” it has the characteristics of excessive proliferation, fast growth rate, tumor cells can appear local infiltration, distant metastasis, poor prognosis and great danger.
Preoperative routine urine and blood tests, urological ultrasound and CT examination can basically clarify the bladder occupying lesions, but cannot determine the nature of the tumor.
3. Histological origin
“Bladder tumors can originate from both epithelial and non-epithelial tissues (mesenchymal tissue).
97% of “bladder epithelial tumors”: benign tumors include uroepithelial hyperplasia and atypical hyperplasia, papilloma, polyps and adenoma; malignant tumors include uroepithelial cell carcinoma, squamous cell carcinoma, glandular cell carcinoma, small cell carcinoma and metastatic carcinoma, among which uroepithelial carcinoma of the bladder is the most common, accounting for more than 90% of bladder tumors, squamous cell carcinoma of the bladder is less common, accounting for 3% to 7% of bladder tumors. Bladder adenocarcinoma is even less common, accounting for <2% of bladder tumors.
The 3% of non-epithelial bladder tumors mainly originate from muscle, blood vessel, lymph and nerve tissues: benign tumors include smooth muscle tumor, rhabdomyosarcoma, hemangioma, fibroma, pheochromocytoma and lipoma, mucinous tumor, bone tumor, etc.; malignant tumors include smooth muscle sarcoma, rhabdomyosarcoma, carcinosarcoma, malignant lymphoma, malignant melanoma, fibrosarcoma, bone and chondrosarcoma, etc.
4.Incidence
Many people are concerned about the chance of benign bladder tumor, there are benign bladder tumors, but the chance is not very big, the proportion of benign bladder tumor is <10%.
5.Prognosis of survival
The prognosis of survival needs to be determined by the overall condition of the patient, including tumor stage (size, shape, number, whether in situ cancer, natural course, tissue typing, etc.), treatment plan, etc.
Types of benign “bladder tumors” and diagnosis and treatment opinions
Some benign “bladder tumors”, their diagnostic methods and treatment countermeasures are summarized as follows.
1.Intrusive papilloma of the bladder
This disease is mostly found in the bladder triangle and is caused by abnormal local epithelial proliferation due to chronic inflammatory stimulation. However, because of its potential for malignancy, it requires regular follow-up. The recurrence rate of involuted papilloma is 1-7%, mostly in the form of uroepithelial carcinoma.
2.Bladder smooth muscle tumor
It is the most common benign tumor of non-epithelial origin, and most patients are accompanied by uterine smooth muscle tumor. The most common cause is dyspareunia, which can be accompanied by hematuria, lower abdominal tumor, pelvic pain and stress incontinence. Treatment can be transurethral electrodesiccation, tumor enucleation or partial cystectomy. The prognosis of the disease is good, and there are occasional cases of malignant transformation. We believe that early detection and early treatment can prevent a series of complications caused by obstruction, which is the key to treat the disease.
3.Bladder hemangioma
The incidence of hemangioma occupies the second place among non-epithelial benign tumors of the bladder, with cavernous hemangioma being the most common, in addition to capillary type and arteriovenous type. Treatment of small tumors is usually done by transurethral electrocautery, electrodesiccation or laser treatment, while large tumors require partial cystectomy with good prognosis.
4.Fibroma of the bladder
Cystic fibroma is rare and originates from the fibrous tissue of the bladder wall. Microscopically, it is divided into rigid and soft tumors, the former is mainly fibrous tissue and appears as fibrous histiocytoma, while the latter may appear as fibrolipoma and angiolipoma. The clinical manifestations and cystoscopic examination are basically the same as those of smooth muscle tumors of the bladder. Treatment is the same as that for smooth muscle tumor of the bladder, and the prognosis is good.
5.Pheochromocytoma of bladder (paraganglioma)
It accounts for about 0.06% to 0.33% of bladder tumors, is usually found in the bladder triangle, and the age of prevalence is 30-40 years old. The typical symptoms are blood pressure changes associated with urination, intermittent hematuria and episodic hypertension triad, manifested by elevated blood pressure during urination, headache, palpitations and sweating, and even syncope, which may be relieved after a few minutes, and intermittent sarcoid hematuria in about half of patients. The main cause is the stimulation of the tumor during bladder filling or surgical operation, which leads to increased secretion of catecholamines and manifestations such as pallor, sweating, rapid pulse and headache. When the bladder is emptied and the irritation becomes less, the symptoms gradually resolve. Blood and urine catecholamines and urinary vanillyl bitter almond acid (VMA) are significantly elevated at the onset of symptoms. Most pheochromocytomas of the bladder are benign and a few are malignant. Flow cytometry and immunohistochemistry (MIB-1) of tumor cells are valuable for differentiation of benign and malignant, but histopathological examination is needed for definite diagnosis. If the tumor is small and protrudes into the bladder, TURBt surgery can be considered, while the rest are mainly open cystectomy. Preoperative preparation must be done according to adrenal pheochromocytoma, requiring preoperative application of α and β receptor blockers, and after strict control of blood pressure, elective surgical treatment.
6.Nephrogenic adenoma of the bladder
It is derived from the remnants of the middle renal duct, for the urinary tract epithelium occurred similar to the terminal tubular tissue potential cell differentiation value-added, often accompanied by adenocystitis, mostly unifocal, can be seen in the renal pelvis, ureter, bladder, urethra and other migratory epithelial coverage sites, can occur at any age break, both men and women can develop, to middle-aged men are more common, the pathogenesis of the disease is not clear, common causes include urinary obstruction caused by urinary The pathogenesis of the disease is still unclear, but common causes include urinary kinetic changes due to urinary tract obstruction, urological diseases such as bladder stones, and medical causes such as transurethral lumpectomy and bladder perfusion chemotherapy. The disease has no typical clinical symptoms and may include dyspareunia, hematuria, frequency or painful urination. Because it is indistinguishable from adenocystitis and bladder cancer by the naked eye and has a high local recurrence rate, it is difficult to confirm the diagnosis preoperatively and is often found by postoperative pathology, often requiring immunohistochemistry to confirm the diagnosis. Treatment is often by transurethral endoscopy, and the prognosis is average, with a perceived tendency for malignancy, so review should be strengthened.
7. Endometriosis of the bladder
Endometriosis, a lesion in which the endometrial tissue with growth function is ectopic outside the uterine cavity, is a common disease in women of childbearing age, mostly occurring in women aged 30-40 years, but ectopic to the bladder is rare. Typical symptoms of bladder endometriosis are urinary frequency, painful urination, hematuria, some with urinary difficulty first, symptoms often appear before menstruation, and some patients have a history of pelvic surgery. Surgical treatment should be the preferred option, of which partial cystectomy is the most appropriate treatment. If the ectopic mucosa cannot be completely removed, the recurrence rate is high.
In conclusion, benign bladder tumors are rare clinically, but due to their own clinical symptoms causing urinary obstruction, hematuria and other clinical symptoms, some diseases have the risk of malignant transformation, the preoperative diagnosis rate is low, and the diagnosis needs to be considered in combination with clinical manifestations, ultrasound, CT and cystoscopy + biopsy. However, it has also been misdiagnosed as abdominal or pelvic tumor, so in clinical practice it can be contacted with related disciplines (general surgery, gynecology, etc.) for joint research and discussion to reduce the occurrence of misdiagnosis.