The aim of this case report is to describe the appearance on magnetic reson
ance imaging (MRI) of an incidentally found adenomatoid tumor of the adrena
l gland, and to evaluate the utility of MRI in characterizing this type of
tumor. The appearance of the tumor was nonspecific on T1-weighted in-phase,
opposed-phase, and T2-weighted images, as well as its behavior after param
agnetic contrast administration, outlining the differential diagnosis among
carcinoma, metastatic tumors, and pheochromocytoma. After surgery, the pat
hologic diagnosis was adenomatoid benign tumor of mesothelial origin. Altho
ugh MRI enables the characterization of most benign lesions of the adrenal
gland, the appearance of other lesions is nonspecific. In our case. MRI did
not assist in preoperative diagnosis, guiding us towards a diagnosis of ma
lignancy.