Diagnosis, localization and treatment of pheochromocytoma in MEN 2 syndrome.

Abstract Pheochromocytomas/paragangliomas (PHEOs/PGLs) in patients with MEN 2 are usually found in the adrenals after the manifestation of medullary thyroid cancer. These PHEOs are commonly bilateral and hormonally active. Tachycardia, diaphoresis and cephalalgia are encountered in 40 %-80 % of patients with PHEOs; hypertension is very prevalent. Plasma concentrations of free metanephrines (or free metanephrines in urine) are best used for the biochemical diagnosis of PHEO/PGL. In patients with biochemically-proven PHEOs/PGLs, anatomical imaging with computed tomography (CT) and/or magnetic resonance imaging (MRI) should be used. False-positive CT/MRI studies can ensue and the specificity of CT/MRI may vary from 50%-90%. Functional imaging (implementing nuclear medicine modalities) should follow anatomical imaging; modalities with PHEO/PGL-specific ligands are a first choice. Among these specific modalities positron emission tomography (PET) with [18F]-fluorodopamine ([18F]DA) stands out as the best overall method. If PHEO/PGL-specific modalities turn out to be negative functional imaging should follow with nonspecific modalities (particularly if recurrent, metastatic or malignant disease is suspected). Treatment is surgical, with expanding use of laparoscopic approaches. Overall half of the patients with malignant PHEOs remain alive for 5 years.