Endocrinological and imaging analyses of adrenal incidentalomas with hypertension and/or diabetes mellitus

Abstract

Adrenal tumors showing no clinical manifestations (incidentaloma) are frequently encountered during imaging analysis upon routine examinations. These tumors are sometimes associated with hypertension and/or diabetes mellitus (DM). We have examined six cases of incidentalomas with these symptoms in this study. All patients underwent endocrinological evaluation by measuring plasma cortisol and aldosterone levels to assess adrenocortical function. The levels of urinary 17-hydroxysteroids, 17-ketosteroids and catecholamines were also measured. Imaging analysis were performed by using 131I-adosterol scintigraphy, computed tomography and magnetic resonance imaging. Whereas one case was diagnosed as having an adrenal adenoma without the examination of a surgical specimen, other cases underwent surgical removal of the tumor, and final diagnoses were made by pathohistological examination of the tumors. Three cases were diagnosed as having adrenocortical adenomas (one was functioning and others were non-functioning) and one case was diagnosed as having a functional adrenocortical carcinoma. Adenomas were found to produce either non-functional steroids or a small amount of functional steroid hormones. The adenoma patients all suffered hypertension, whereas one of the adenoma patients and the carcinoma patient showed signs of DM. By contrast, of the six cases, one case was diagnosed as having an adrenal cyst, and one case was diagnosed with myelolipoma. Although these two cases suffered DM and hypertension, respectively, it seemed to be unlikely that these clinical symptoms were caused by the adrenal disease. Thus, the present analysis of the six incidentaloma patients suggests that once an adrenal incidentaloma patient with hypertension and/or DM is found, both endocrinological and imaging examinations are necessary to determine the indication of surgical treatment. This analysis supports the present consensus that non-functional adenomas whose sizes are 3cm or less and whose sizes do not change at any reevaluation period, as well as adrenal cysts and myelolipoma should not be surgically removed.