Vanishing Bone Metastases in 18F-FDG PET/CT

Abstract

A 36-year-old woman with a history of large B-cell lymphoma was referred for the exploration of sclerotic bone thoracic vertebral metastases discovered on a contrast-enhanced CT examination. 18F-FDG PET showed no pathological uptake in the affected vertebrae, as well as normal vertebral density on the coupled unenhanced CT. After review of the initial contrast-enhanced CT, a left brachiocephalic vein stenosis was noted, leading to a retrograde contrast filling of the accessory hemiazygos vein and the capillary spaces within the vertebrae, mimicking sclerotic metastases.

Mimicker of Osteoblastic Skeletal Metastasis on 18F-FDG PET/CT Scan in a Case of Primary Mediastinal Germ Cell Tumor

“…On viewing the corresponding plain CT chest sagittal images in the bone window ( E ), no sclerotic lesions were appreciated in D3–D4 vertebrae. This led us to realize that the FDG-avid, sclerotic-appearing lesions in D3–D4 vertebrae visible only on a CECT scan were indeed dilated intravertebral venous collaterals mimicking metastasis, which was clinically consistent with SVC obstruction and dilated venous collaterals in the chest 4,5 . Metastatic sites in primary mediastinal germ cell tumors may include the lung, lymph node, liver, and bone 6 .…”

“…This led us to realize that the FDG-avid, sclerotic-appearing lesions in D3-D4 vertebrae visible only on a CECT scan were indeed dilated intravertebral venous collaterals mimicking metastasis, which was clinically consistent with SVC obstruction and dilated venous collaterals in the chest. 4,5 Metastatic sites in primary mediastinal germ cell tumors may include the lung, lymph node, liver, and bone. 6 However, bone and bone marrow metastasis is rather unusual with very poor prognosis.…”