Ectopic adrenal myelolipoma presenting as a splenic mass

Myelolipoma is a benign tumor composed of mature adipose tissue and hematopoietic elements. Although they are most commonly found in the adrenal glands, extra-adrenal myelolipomas are well documented. We describe a case of myelolipoma arising within or adjacent to the spleen of a patient with sickle cell disease. This encapsulated tumor contained myeloid and adipose components, as well as clear cells resembling adrenal cortical tissue. Although ectopic adrenal tissue has not been reported in the spleen, we feel that this is the most likely site of origin of this mass. To our knowledge, this is the first instance of this neoplasm presenting as a splenic mass. The possible pathogenesis and etiology of this unusual lesion is discussed.