Endocrine Abstracts

Background: Pheochromocytoma (Ph) is the tumor that is fatal if do not suspect and treat it on time. It is supposed that size of tumor is correlated with its synthetic activity. Here we present a clinical case of giant Ph with low synthetic activity that could have been recognized as adrenal cancer, which, in turn, may have led to wrong treatment.

Clinical case: Young woman, 28 years old, presented with the adrenal incidentaloma. She had not any complaints, her history was not notable for any disease. CT showed right adrenal heterogeneous mass 9×8×7.6 cm with native density – 30-69HU, which eclipsed liver and was inseparable from the inferior vena cava. Because of young age, absence of any clinics, parameters of native density, adrenocortical cancer was strongly suspected. According to protocols hormonal examination was performed: plasma cortisol after 1-mg DST was 45 nmol/l (50 nmol/l), 24-hour urinary fractionated metanephrines were 248 mcg (320 mcg), 24-hour urinary fractionated normetanephrines were 2453.0 mcg (390 mcg). Because of discordance between tumor size and relatively low normetanephrines concentration, additional laboratory testing was performed. Hook-effect was excluded, the level of metabolites was the same. Since there was a possibility of concurrent Ph and cortical carcinoma, in order to set definitive diagnosis MIBG-scintigraphy was performed. Scintigraphy revealed signs of hormonal activity of right adrenal tumor. The diagnosis of Ph was made. Patient was preoperativelly given alpha-blocker for 14 days. Right laparoscopic adrenalectomy was performed without any complications. Histologic picture proved that there was Ph. Postoperativelly catecholamine metabolites were normal. Genetic testing did not show VHL and SDHD mutations.

Conclusions: The size of Ph does not always correlates with its hormonal activity. At the same time, strict adherence to protocols is necessary in all cases despite the fact that sometimes we can see ‘obvious’ signs of the other disease such as adrenocortical cancer in our case.