Too Massive and Too Atypical to Be Benign: The Unexpected Face of a Giant Adrenal Myelolipoma

Adrenal myelolipomas (AMLs) are rare benign tumors composed of adipose and myeloid tissue. They are most often discovered incidentally and generally remain small in size. However, giant forms can radiologically mimic a malignant tumor, leading to aggressive investigations and treatment. We report the case of a patient who was hospitalized for investigation of a right adrenal mass, revealed by lumbar pain. An abdominal CT scan showed a large, heterodense interhepatorenal mass exerting a mass effect on the ipsilateral kidney with peripheral calcifications. The mass was excised and submitted for histological evaluation. The results of the histological study revealed an AML. Giant myelolipomas are rare and represent a real diagnostic challenge. Their large size, heterogeneous components, and necrotic or hemorrhagic changes can mimic a malignant tumor. Surgery remains indicated in cases of diagnostic uncertainty, compressive symptoms, or tumors larger than 6 cm. Histology remains the only way to establish a definitive diagnosis. This case highlights the difficulty of distinguishing a giant myelolipoma from a malignant adrenal tumor.