Pheochromocytoma is a tumor that most often arises in the medulla of the adrenal glands, but it can also be found in other locations such as the neck and chest. Benign forms of pheochromocytoma are mostly diagnosed, although malignant forms characterized by local and distant spread (metastasis) can also be found in about 10% of patients.
When and how does pheochromocytoma occur?
Pheochromocytomas occur hereditary (about 30% of cases) and sporadically. Although changes in a dozen genes responsible for the formation and development of pheochromocytoma have been identified so far, a mutation of the proto-oncogene RET is found dominantly in sporadic forms and MEN2A and MEN2B syndromes, in neurophobromatosis type 1 there is a mutation of the tumor suppressor gene NF-1 and in von Hippel-Lindau syndrome loss of function of the suppressor gene VHL. In addition to the above, mutations were also identified in the GDNF, MAX and TMEM127 genes, which also increase the risk of pheochromocytoma development.
What are the symptoms of pheochromocytoma?
The main complaints in patients are the effects of increased secretion of hormones from the tumor of the medulla of the adrenal gland (adrenaline, noradrenaline). Attacks of elevated blood pressure (sometimes up to 250/180 mmHg) occur, accompanied by rapid heartbeat (tachycardia) with a feeling of heart palpitations and cardiac arrhythmias, headache, nausea, difficulty breathing, vomiting, general weakness, restlessness, facial flushing, tinnitus, tremors and anxiety.
Other complications of high blood pressure (damage to the eyes, blood vessels, heart, brain and kidneys) may also be present. Depending on the size, the tumor can exert pressure on the surrounding organs, disrupting their function. Other hormones such as parathyroid hormone-like hormone can sometimes be secreted from the tumor, which causes calcium levels in the blood to rise.
Diagnosis and treatment
The diagnosis is established by a specialist examination, laboratory and hormonal tests, genetic testing and various instrumental procedures such as ultrasound, CT and MR.
Treatment of pheochromocytoma is carried out medically and surgically.