Pheochromocytoma/Paraganglioma: A Poster Child for Cancer Metabolism

Sergei G. Tevosian; Hans K. Ghayee


J Clin Endocrinol Metab. 2018;103(5):1779-1789. 

In This Article

PCC/PGL: Where Are We Now?

The initial diagnosis of PCC/PGL is usually made by inspecting plasma metanephrines or 24-hour urine for catecholamines and metanephrines.[6,7] After the biochemical evaluation, imaging studies such as computed tomography scans or magnetic resonance imaging studies are routinely conducted. To evaluate the extent of possible metastatic disease, the metaiodobenzylguanidine scan, for which a radiolabeled compound is taken up by PCC/PGL cells, traditionally is used to determine the tumor location. However, studies have reported better sensitivity for the fluorodeoxyglucose positron emission tomography approach to identify aggressive PCC/PGL disease.[8] Recent research is recognizing 68Ga-labeled somatostatin analogs (DOTATATE) as a promising modality in finding PCC/PGL disease.[9] This advancement in PCC/PGL imaging has come about through understanding of the alteration in glucose metabolism in these tumors.[10]

The mainstay of PCC/PGL treatment is surgical, because there are no medical therapies for metastatic disease and it is estimated that a median overall survival rate for patients with specific mutations is about 3 years.[11] Even when a primary tumor is removed, a pathologist is not able to tell if the tumor is malignant or benign. The determination of metastatic disease is made when the patient's imaging results are consistent with metastatic disease. Clues to whether the patient may have metastatic disease have come with the understanding of new genes associated with malignant behavior, which is discussed later in this review.