Peculiarities of pheochromocytoma diagnostics

Milda Gylytė1, Aistė Čemerkaitė1, Ieva Zailskaitė1

1Lithuanian University of Health Sciences, Medical Academy, Faculty of Medicine

Abstract

Pheochromocytoma is a rare tumor originating in the adrenal medulla. The tumor can be diagnosed at any age, but the most common is 30-50 years. century. The tumor can be diagnosed at any age, but the most common at age of 30-50 years. 5 year survival rate of localized pheochromocytomas reaches 95%, advanced or recurrent tumors – 50-60%. There are no specific data on the prevalence of pheochromocytoma in Lithuania. Pheochromocytoma is difficult to diagnose because it causes a variety of symptoms which are not specific. Only a subset of patients experience the typical triad of symptoms caused by pheochromacytoma: headache, palpitations, and diaphoresis. One of the most common symptoms of this tumor is high blood pressure. However, even this symptom does not always occur. The variety of symptoms of pheochromocytoma are determined by the release of different catecholamines such as dopamine, norepinephrine, and epinephrine. Although the onset of symptoms is related to the amount of released catecholamines, it is not always related to the size of the tumor, found in the imaging studies.  The biochemical diagnosis of pheochromocytomas consists of measuring levels of catecholamines and it‘s metabolite products (metanephrine and normetanephrine). It‘s appropriate to measure all three catecholamines – epinephrine, norepinephrine and dopamine, because tumor can synthesize one, two, or all three of them at the same time.

Imaging tests should be employed for localization after a biochemical diagnosis is confirmed. Phaeochromocytomas have variable imaging features that may mimic both benign and malignant adrenal neoplasms. CT is recommended as the first-choice imaging modality on diagnostics of pheochromocytoma. MRI is recommended for children, pregnant women, and those with recent excessive radiation exposure, with metastatic disease. MIBG scintigraphy is recommended as a functional imaging modality in some patients with an increased risk for metastatic disease. The use of 18F-FDG PET/CT scanning is suggested in patients with metastatic disease.

Keywords: tumor, arterial hypertension, triad, catecholamine, phaeochromocytoma crisis, diagnostics, CT, MRT.