Incidentally discovered pheochromocytoma (PH)
N. Kesri1, A. Boudiba2 & F. Chentli1
The main concern of endocrinologist exploring an adrenal incidentaloma (AI) is the identification of malignant and/or secretant AI leading to rapid cure by removal of the tumor. PH remains one of the most difficult lesions to diagnose. In this study we analyze PH clinic, morphologic and secretory profile. Among a series of 91 AI recruited between 1987 and 2007 having benefited from an adrenal exploration, 56 have been removed and 18/56 were diagnosed as tumors of medullar origin.
Results: This group is composed of 15 benign and 2 malignant PH and 1 neuroendocrine tumor. Benign PH are found in 7F/8H, 44.2+/−14y. Initial presentation includes HTA in 40%, paroxystic in 30%, adrenergic signs in 20%, DS in 20%, weight loss in 13.3%. Average axis PH=64.4+/−29.7 mm, heterogeneous spontaneous density in 84.6%. Rise of urinary metanephrines (uMN) is noted in 47.6% of PH, 23.8% of cortical AI and 28.6% of extra adrenal AI (sensitivity 52.9% specificity 61.7%) threshold 4times normal rates is more contributory to PH diagnosis. Within this group, PH are sécrétant in 60% with concentration of uMN =3.1+/−3.2 mg/24 h. Iodine 131 MIBG Adrenomedullary Scintigraphy showed a hormonal/isotopic match in 71% (sensitivity 62.5% specificity100%) Malignant PH have been diagnosed in one hypertensive male, AI 200 mm, uMN↑3,02 mg/24 h, no fixation and one female, AI 100 mm, ↑Dopamine.
Conclusion: In this study PH represented 32% of the operated AI and are in more than 80% benign, recruited among large AI with malignant radiological phenotype. 3/5 patients are normotensive. The current uMN assay is not very sensitive, secretory activity is noted in about half cases. Scintigraphy revealed excellent specificity and a hormone-isotopic match in about 3/4. The discordant aspects are related to the relative small size of AI, the significance of intratumoral metabolism or the scarcity of storage granules.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.