Bladder pheochromocytoma

　　1. Etiology

　　The etiology of pheochromocytoma is not yet clear, like other tumors, but several special conditions may be related to the etiology of pheochromocytoma. Sympathetic neuron cells in the early embryonic stage originate from the neural crest and neural tube, and are the common precursors of sympathetic neuroblasts and chromaffin cells. Most chromaffin cells migrate to the adrenal cortex of the embryo, forming the adrenal medulla. Another part of the chromaffin cells migrate with sympathetic neuroblasts to the paravertebral or pre-aortic sympathetic ganglia, forming extra-adrenal chromaffin cells. Extra-adrenal chromaffin cells mature as early as 9-11 weeks of embryonic development, earlier than the adrenal medulla chromaffin cells. After birth, while the chromaffin cells of the adrenal medulla mature, the extra-adrenal chromaffin cells regress and gradually disappear. Therefore, the chromaffin cells distributed in many places in the embryo can only retain the adrenal medulla cells at maturity. Under certain special circumstances, these homologous neuroectodermal cells can develop corresponding tumors.

　　Second, pathogenesis

　　1, Pheochromocytoma of the bladder is often limited to the bladder wall or grows only to the outside of the wall. The differentiation between benign and malignant tumors does not rely on biological indicators or cytological characteristics, but should take the tumor infiltrating capsule or adjacent tissue, intravascular tumor emboli in the muscle layer, or the presence of metastatic foci in extravesical non-pheochromocytic tissue as the basis for diagnosing malignant pheochromocytoma.

　　2, The occurrence of pheochromocytoma of the bladder may be related to the residual pheochromocytic tissue in the bladder. The tumor is nodular or polypoid, with a slightly hard texture, and has a clear boundary with normal bladder tissue. However, most of the bladder muscle layer adjacent to the tumor is destroyed, and the mucosa on the surface of the tumor may have ulcers. The cross-section of the tumor is homogeneous, brown or yellow-brown. The tumor cells are polygonal or fusiform, with a large number of cytoplasmic granules and are easily stained with chromium salts. The cell clusters are lobular, fascicular, or acinar in shape.

　　1, Hypertensive crisis:It is a very critical syndrome that occurs in patients with hypertension. It often occurs under the influence of adverse triggers, with blood pressure suddenly rising to above 26.6/16 kPa (200/120 mmHg), resulting in acute damage to the heart, brain, and kidneys.

　　2, Hypertensive retinopathy:It refers to the persistent increase in systemic arterial blood pressure, causing the destruction of the blood-retinal barrier, plasma leakage, and exudation of formed elements in the blood vessels, resulting in retinal edema, hemorrhage, ischemia, or exudative spots. In severe cases, retinal detachment may occur.

　　The typical clinical manifestations of pheochromocytoma of the bladder include hypertension, hematuria, and diabetes. Hypertension can be persistent or intermittent. The characteristics are that there is paroxysmal hypertension, an accelerated pulse, pale complexion, headache, sweating, and other symptoms when the bladder is full. The symptoms reach their peak during the process of urination, and fainting may occur. The symptoms gradually subside after urination. Hematuria is mostly painless, intermittent gross hematuria. Pheochromocytoma of the bladder without endocrine function may have no symptoms except for local lesions.

　　The etiology of pheochromocytoma is not clear, like other tumors, but several special situations may be related to the etiology of pheochromocytoma. Sympathetic neuron cells in the early embryonic stage originate from the neural crest and neural tube, which are the common precursors of sympathetic neuroblasts and pheochromoblasts. Most pheochromoblasts migrate to the adrenal cortex of the embryo, forming the adrenal medulla of the embryo. Therefore, there is no preventive method for this disease. Early detection, early diagnosis, and early treatment are of great significance for the indirect prevention of this disease.

　　The determination of urinary catecholamine (catecholamine, CA) and its metabolites (3-methoxy-4-hydroxy mandelic acid VMA) is helpful for qualitative diagnosis, but the positive rate during non-attack period is low, and the positive test of phentolamine suppression is an important diagnostic basis.

　　1. Ultrasound, CT, or MRI can determine the size of the tumor and whether there are metastatic foci, and CT is a practical imaging method with great value in the localization diagnosis of ectopic pheochromocytoma.

　　2. The positive rate of cystoscopy is about 80%, and it can be seen that the local bladder mucosa protrudes into the lumen,呈基底广的半球状, with a smooth surface, congestion, and redness. Since the pheochromocytoma is located within the bladder wall, only mucosal biopsy has a low positive rate and is prone to bleeding.

　　3. 131I-MIBG imaging can be specifically localized, and the higher the activity of the pheochromocytoma, the more 131I-MIBG is concentrated, and the sensitivity of 131I-MIBG diagnosis for bladder pheochromocytoma is higher than that of B-ultrasound, CT, and has been widely used.

   　1. Foods that are good for bladder pheochromocytoma patients:

　　Provide high-sugar, high-protein diet.

　　2. Foods that are best not to eat for bladder pheochromocytoma:

　　Avoid tea, chocolate, coffee, and foods containing flavoring.

　　First, Treatment

　　1. The treatment of pheochromocytoma of the bladder is mainly surgical, and partial cystectomy is often used. If the tumor is located in the trigone area or has a wide range and infiltrates adjacent tissues, total cystectomy can be performed. Since there may be severe fluctuations in blood pressure during surgery, sufficient preparation should be made before surgery, such as the use of adrenergic receptor blockers such as phenoxybenzamine, expansion of blood volume, and improvement of cardiac function to prevent possible postoperative hypotension and hypoglycemia. Surgery is usually performed under general anesthesia and with electrocardiographic monitoring.

　　2. For malignant pheochromocytoma of the bladder that cannot be resected or widely metastatic, in addition to phenoxybenzamine or methyltyramine to relieve hypertension, internal radiation therapy such as 131I-MIBG can be performed; chemotherapy is usually not sensitive; some scholars have conducted large sample observations on radiotherapy for malignant and recurrent pheochromocytoma of the bladder, considering that radiotherapy has great clinical application value. In addition to open surgery, there have been reports of laparoscopic partial resection of pheochromocytoma of the bladder recently.

　　Second, Prognosis

　　Long-term follow-up should be noted after surgery, and cystoscopy is an important method to observe whether there are malignant manifestations of tumors.