Appearance of adrenal myelolipomas on 2-deoxy-2-(18F) fluoro-D-glucose positron emission tomography-computed tomography

Abstract

With the widespread use of 2-deoxy-2-(18F) fluoro-D-glucose positron emission tomography-computed tomography (FDG PET/CT) in oncologic imaging, it has become increasingly important for physicians who interpret FDG PET/CT scans to confidently recognize the spectrum of incidentally encountered benign and malignant findings. The adrenal glands represent an interesting nexus of multiple rare and common benign intrinsic tumors as well as metastases from a variety of primary malignancies. Given the breadth of adrenal gland pathology, careful description of the FDG PET/CT appearance of these pathologies is of value to help reduce misinterpretation. In this manuscript, we retrospectively and systematically review the FDG PET/CT imaging characteristics of benign adrenal myelolipomas in a small consecutive patient series. The myelolipomas in this series demonstrated differing degrees of macroscopic fat visible on CT, with generally mild FDG uptake fusing to the nonfatty portions of the lesions. At imaging follow-up, all of the myelolipomas in this series remained unchanged in appearance, helping to confirm their benign nature. The typical appearance of a myelolipoma on FDG PET/CT is a fat-containing adrenal mass with low-level FDG uptake in the nonfatty aspects of the mass, and such a lesion requires no further imaging workup.

A case of perirenal extra-adrenal myelolipoma mimicking liposarcoma

“…In the current case, the tumor showed slight FDG uptake, with an SUVmax of 1.8. In a report of 10 patients with myelolipoma, 3 the average SUV-max was 0.7 in the fat-component and 1.4 in soft tissue myeloid component. In contrast, in 20 patients with liposarcoma, 4 the average SUV-max was 3.15 in well-differentiated liposarcoma and 9.23 in dedifferentiated liposarcoma.…”

Adrenal Lesions: A Review of Imaging

“…On PET-CT, AML appears as a mass that shows minimum homogeneous FDG uptake in the soft tissue and no FDG uptake in the fat component [ 35 ]. On MRI, macroscopic fat components are hyperintense on T1- and T2-weighted images, while blood-containing components are hypointense on T1-weighted and moderately hyperintense on T2-weighted images.…”