Endocrine Abstracts

Introduction: Pheochromocytomas (PHEO) and paragangliomas (PGL) are rare catecholamine-secreting tumors. Some authors proposed that there is a positive linear relationship between tumor size and measurements of metanephrines and an absence of association with catecholamine levels.

Objectives: To review and characterize patients diagnosed with PHEO and PGL in Garcia de Orta Hospital. To determine the relationship between tumor size and measurements of urinary total metanephrines and total catecholamines.

Methods: Retrospective study with revision of medical records, between 1992 and 2013. Statistical analysis was performed by simple linear regression using SPSS 20.

Results: Twenty-three patients diagnosed with PHEO and PGL were identified, corresponding to 13 men (56.5%) and ten women (43.5%). Eighteen cases (78.3%) presented with unilateral PHEO, three cases (13%) with bilateral PHEO and two cases (8.7%) with PGL. We found the following genetic syndromes: multiple endocrine neoplasia type 2A (three patients), neurofibromatosis type 1 (two patients) and familial PGL type 4 (one patient). After surgery local recurrence occurred in two cases. Metastasis was identified in three other individuals who had persistence of disease despite additional therapy. We noticed a strong positive linear relationship between tumor size and measurements of urinary total metanephrines (r=0.72, P=0.004). A linear association between size and levels of urinary total catecholamines was not identified (r=0.5, P=0.171).

Conclusion: This study suggests that an increase in the size of PHEO and PGL is related with a rise in metanephrine levels; an association with catecholamines was not demonstrated. These differences may be related to the fact that the secretion of catecholamines is intermittent, whereas metanephrine formation is a more continuous process.