Imaging findings of pelvic tumor thrombosis extending from sacral bone metastasis of adrenocortical carcinoma

Abstract

We report the imaging findings of a patient with adrenocortical carcinoma who showed pelvic tumor thrombosis extending from sacral bone metastasis. Contrast-enhanced computed tomography demonstrated extensive intraluminal filling defects in the pelvic veins. A lytic lesion in the sacrum was also noted and continuity between the sacral lesion and the filling defect in the branch of pelvic veins was indicated. The filling defects showed increased uptake on positron emission tomography with (18)F-fluorodeoxyglucose and single-photon emission computed tomography with (131)I-iodomethylnorcholesterol, and fusion images with computed tomography aided the localization of the increased uptake areas. Multimodality imaging may be beneficial for the characterization and localization of lesions in patients suspected of having metastatic adrenocortical carcinoma.

Figure 1

In-phase gradient echo MRI demonstrated a 40 mm, well-defined left adrenal mass (a) (arrow). Opposed-phase imaging showed signal decrease in part of the mass (b), indicating lipid content.

Figure 2

Contrast-enhanced CT demonstrated intraluminal filling defects in the right common iliac vein, both internal iliac veins, and their branches ((a)–(d)) (white arrows). A lytic lesion in the sacrum was also noted (c) (black arrowheads) and continuity between the sacral lesion and the filling defect in the branch of the right internal iliac vein was indicated.

Figure 3

Axial PET (a), CT (b), and PET-CT fusion (c) images showed increased FDG uptake in the left adrenal mass (arrowheads). Increased uptake was also seen in the pelvic veins, consistent with a tumor thrombus ((d)–(f)) (arrows).

Figure 4

The posterior whole-body adrenocortical scintigraphy image showed focal uptake in the left adrenal (small arrowhead) and pelvic (large arrowhead) lesions (a). The axial SPECT (b), CT (c), and fused SPECT-CT (d) images confirmed increased uptake in the sacrum (thick arrows) and indicated increased uptake in the vein (thin arrows).