Myelolipoma within a non-functional adrenal cortical adenoma

Myelolipoma within an adrenal cortical adenoma is a very rare cause of adrenal incidentaloma, and only nine cases have been reported in the English and Japanese literature. We report a 66-year-old Chinese man, with a history of hypertension and hyperlipidaemia, who presented with lower limb oedema and had a computed tomography (CT ) of the abdomen done to exclude intra-abdominal mass. His lower limb symptoms resolved after switching his antihypertensive medication. CT of the abdomen showed a large heterogeneously-enhancing mass in the left suprarenal region, measuring 72 mm by 55 mm. Clinical history, physical examination and laboratory results did not show any evidence to suggest metabolic disorder such as Cushing's syndrome, hyperaldosteronism or catecholamine hypersecretion. The patient underwent a left adrenalectomy, and a histopathological study confirmed the mass to be a non-functional adrenal cortical adenoma containing myelolipoma. The patient was well postoperatively and was discharged uneventfully. To the best of our knowledge, this is the first non-functional adrenal cortical adenoma reported; in the nine cases of myelolipoma within an adrenal cortical adenoma reported previously, all the patients had Cushing's syndrome. The literature on synchronous myelolipoma with adrenal adenoma, and myelolipoma within functional adrenal adenoma, is reviewed.