Some of the causes of pheochromocytoma are related to genetics

Pheochromocytoma is a high-risk disease. Although most cases are benign, they have many complications, some of which may even be life-threatening. The onset of the disease is related to genetics, but like many tumors, the cause of the disease is not clear for many people.

The prevalence of pheochromocytoma in hypertensive patients is 0.05% to 0.2%, with the peak incidence being between 20 and 50 years old. 80% to 90% of pheochromocytomas are located in the adrenal glands and are mostly unilateral; tumors outside the adrenal glands are mainly located outside the peritoneum and beside the abdominal aorta. Most are benign, with malignant cases accounting for 10%. As with most tumors, the cause of sporadic pheochromocytoma remains unknown. Familial pheochromocytoma is related to genetics.

The clinical manifestations of this disease vary greatly from person to person, including sudden onset of malignant hypertension, heart failure or cerebral hemorrhage. Approximately 10% of pheochromocytomas are located outside the adrenal glands, 10% are malignant, 10% are familial, 10% occur in children, 10% are bilateral, and 10% are multiple. Clinical symptoms and signs are related to excessive secretion of catecholamines, and include hypertension, headache, palpitations, hypermetabolic state, hyperglycemia, and sweating.

Clinical manifestations:

1. Metabolic disorders

High concentrations of adrenaline act on the central nervous system, especially the sympathetic nervous system, increasing oxygen consumption and increasing the basal metabolic rate, which can cause fever and weight loss. Accelerated liver glycogenolysis and inhibition of insulin secretion lead to impaired glucose tolerance and increased liver gluconeogenesis. Hypokalemia may occur in a few cases, and hypercalcemia may also be caused by the secretion of parathyroid hormone-related peptide by the tumor.

2. Other manifestations

Excessive catecholamines weaken intestinal motility and tension, thus causing constipation, intestinal dilatation, proliferative or occlusive endarteritis of the blood vessels in the gastrointestinal wall, leading to intestinal necrosis, bleeding or perforation; the gallbladder contraction is weakened and the tension of the sphincter of Oddi is increased, which can cause bile retention and gallstones. Severe and long-term illness may lead to renal failure. When patients with intravesical paraganglioma urinate, their blood pressure may rise. Under the action of large amounts of adrenaline, blood cells are redistributed, increasing the white blood cell count in the peripheral blood, and sometimes the red blood cell count may also increase. In addition, this disease may be part of type II multiple endocrine neoplasia syndrome (MEN), which may be accompanied by medullary thyroid carcinoma, parathyroid adenoma or hyperplasia, and adrenal adenoma or hyperplasia.