Myelolipomas are uncommon tumor-like masses composed of heterotopic bone marrow and adipose tissue. They are incidental findings, and their pathological significance is obscure. While they usually occur in the adrenal glands, a few cases have been reported in other parts of the body, mainly in the retroperitoneal area but occasionally also in the chest (3, 4, 8). Though they may be without demonstrable relation to other disease, they are sometimes found in association with severe anemias (1, 2, 5-7). In such cases they have been thought to represent a manifestation of compensatory hematopoiesis. Extramedullary hematopoiesis is not uncommon in severe anemias, but the areas of heterotopic bone marrow, though usually found in fatty tissue (particularly in the retroperitoneal region), only rarely take the form of discrete tumor-like masses (9). Myelolipomas differ from mesenchymomas and teratomas in that they are composed only of fatty tissue and heterotopic bone marrow, without other elements. It is question...