At dynamic CT, Gd-DTPA-enhanced MRI, and digital subtraction angiography, a large adrenal adenoma verified by resection histology presented as a hypervascular tumor. In all imaging modalities, it showed a strong patchy enhancement during the early phases of the passage of contrast media and subsequent intralesional contrast equilibration. This case demonstrates that even high enhancement does not rule out an adrenal adenoma with certainty. In the oncologic patient, therapeutic decisions should not be made on the basis of the contrast behavior of an adrenal lesion alone.