A pheochromocytoma (thesaurus synonym: catecholamine excess; adrenal tumor (broadly defined); ICD-10 D35. 0: Benign neoplasm of other and unspecified endocrine glands (adrenal)) is a neuroendocrine (affecting the nervous system) catecholamine-producing tumor of the chromaffin cells of the adrenal medulla (85% of cases) or of the sympathetic ganglia (nerve cord running along the spine in the thoracic (chest) and abdominal (stomach) regions) (15% of cases). The latter is also called extraadrenal (outside the adrenal gland) pheochromocytoma or paraganglioma. In humans, the adrenal glands are located on the upper poles of both kidneys. Functionally, the adrenal gland combines two distinct organs: it consists of the adrenal cortex and the adrenal medulla.
- The adrenal cortex produces different hormones depending on its anatomical structure:
- Zona glomerulosa: Consists of acidophilic cells that produce mineralocorticoids (aldosterone (activating) and deoxycorticosterone (inactivating)).
- Zona fasciculata: production of glucocorticoids (cortisol (also considered a stress hormone) and corticosterone).
- Zona reticularis: synthesis of sex hormones (androstenedione, dehydroepiandrosterone (DHEA), testosterone).
- The adrenal medulla produces the catecholamines epinephrine, norepinephrine, as well as dopamine, colloquially known as “stress hormones“. This is an adaptation reaction of the organism in special stress situations. Originally, this process served to prepare the body for a possible fight or flight (“fight-or-flight” situation) by releasing energy reserves and increasing cardiovascular activity (acceleration of the heartbeat, increase in blood pressure).
Pheochromocytomas produce catecholamines. Two-thirds of pheochromocytomas secrete (secrete) norepinephrine and epinephrine, while extraadrenal tumors located above the diaphragm (diaphragm) produce only norepinephrine. Malignant (malignant) pheochromocytomas also produce dopamine. Due to the excess of catecholamines, hypertensive crises (high blood pressure crises; blood pressure values > 230/120 mmHg) occur. Pheochromocytoma is found in approximately 0.1-0.5% of all hypertensions. 90% of pheochromocytomas occur unilaterally (unilateral) and 10% bilaterally (bilateral). Pheochromocytomas can be divided into the following forms:
- Sporadic pheochromocytoma (75% of cases) – with no apparent cause.
- hereditary (genetic) pheochromocytoma (25% of cases) – in this case, pheochromocytoma occurs in the context of the following diseases:
- Multiple endocrine neoplasia (MEN), type 2a (synonym: Sipple syndrome) – genetic disorder leading to various benign and malignant tumors; the thyroid, adrenal medulla, and parathyroid glands are frequently affected.
- Von Hippel-Lindau syndrome, type 2 – rare, hereditary tumor disease; belongs to the group of forms of phakomatoses (group of diseases with malformations in the skin and nervous system / cerebellum).
- Neurofibromatosis, type 1 – autosomal dominant and monogenic inherited multi-organ disease affecting mainly the skin and nervous system.
- Familial paraganglioma (mutations of succinate dehydrogenase B/C/D).
- Other gene mutations
Frequency peak: the sporadic form occurs predominantly between the ages of 40 and 50 years, while the hereditary form is clustered at an age < 40 years. The incidence (frequency of new cases) is approximately 1 case per 100,000 population per year. Course and prognosis: 85% of pheochromocytomas are benign (benign), 15% are malignant (malignant). In extraadrenal tumors, up to 30% may be malignant. If the pheochromocytoma is removed early and no other diseases are present, the prognosis is good. More than half of patients with benign pheochromocytoma have blood pressure within the normal range after surgery. The others also have essential hypertension (high blood pressure with no apparent cause). Pheochromocytoma can be recurrent (recurring). The recurrence rate is approximately 10-15%. In 30-50% of cases of paraganglioma, metastases (daughter tumors) occur in the liver, lungs and bones.Annual endocrinological (hormonal) follow-up examinations are recommended.
