Figure 9b. Collision tumor with associated myelolipoma and adenoma. (a) Contrast-enhanced CT scan shows a regular, ovoid mass of the right adrenal gland with a fatty component (-84 HU). (b) Coronal FLASH two-dimensional gradient-echo T1-weighted MR image (690/12) shows a heterogeneous mass with some well-limited hyperintense areas (arrow). (c) T2-weighted MR image (2,000/90) shows that these areas (arrow) have the same high signal intensity as retroperitoneal fat. (d) T1-weighted MR image (690/12) obtained with fat suppression shows heterogeneous enhancement and the lipidic nature of the corresponding areas (arrow). (e) Photograph of the gross specimen shows the lipidic areas as yellow nodules (arrowheads). (f) Photomicrograph (original magnification, x4; hematoxylin-eosin stain) shows the association of adenomatous tissue (white *), fatty tissue (solid arrow), fibrotic tissue (open arrow), and hemorrhagic vascular structures (black *).