Myelolipomas have been reported in patients with congenital adrenal hyperplasia (CAH). ACTH excess, as seen with non-adherence to glucocorticoid therapy, may be responsible for tumor development. We report a case of a 51-year-old man with classic salt-wasting CAH managed on prednisone 7.5 mg daily and fludrocortisone who presented with chronic back pain and was found to have giant bilateral retroperitoneal masses. On computed tomography (CT) imaging, the masses were heterogeneous, but contained predominantly low-density fat attenuation. The tumors were resected due to concern for malignancy and mass symptoms. Pathologic examination identified both retroperitoneal masses as myelolipomas. The left tumor was 34×20×13 cm and weighed 4.7 kg and the right tumor was 20 cm in the largest dimension. Adrenal tissue was present in the specimen. The patient reported long-term compliance with glucocorticoid treatment. However, no biochemical monitoring of ACTH levels had occurred. Therefore, it is unclear if ACTH excess contributed to the development of these large tumors in this patient. It was presumed that both adrenal glands were inadvertently removed during surgery and the patient was treated with physiologic replacement doses of hydrocortisone and fludrocortisone postoperatively. In this case, the bilateral adrenalectomy was inadvertent. However, adrenalectomy can be considered as a treatment option in patients with classical CAH under certain circumstances to avoid complications of glucocorticoid excess.
Myelolipomas should be considered in the differential diagnosis of adrenal or retroperitoneal masses in patients with CAH.
On CT imaging, myelolipomas are seen as heterogeneous masses with low-density mature fat interspersed with more dense myeloid tissue.
Myelolipomas are usually unilateral and measure <4 cm; however, very large and bilateral tumors have been reported.
Treatment of CAH typically involves using supraphysiologic doses of glucocorticoid to suppress adrenal hyperandrogenism. Bilateral adrenalectomy is an alternative treatment option in patients with CAH.
There is an association between ACTH excess and increased incidence of adrenal myelolipoma but the direct causal link remains to be established.