Vertebral enhancement due to venous congestion (VEVC) has been described in some patients with mediastinal masses partially or totally occluding the superior vena cava (SVC) and in patients with intravascular devices (central venous catheters, pacemakers, etc.) who develop secondary thrombosis of the central veins of the chest.1 When occlusion occurs in the SVC or other central veins of the chest, such as the innominate vein or the right brachiocephalic vein, venous collaterals develop. These venous collaterals ensure venous drainage from the head, neck, arms and upper thorax via the azygos/hemiazygos system, the internal mammary veins, and/or the epigastric veins. The intervertebral and basivertibral veins are tributaries of the azygos/hemi7azygos system, and the VEVC phenomenon may occur if thrombosis of a central vein of the chest causes drainage difficulties. In VEVC, intravenous contrast medium travels in a retrograde direction until it reaches the spongy bone of the upper dorsal vertebrae, causing marked enhancement that can simulate focal sclerotic bone lesions.2–4 We report a case of VEVC in a cancer patient with chronic thrombosis of the innominate vein.

This was a 57-year-old woman with a personal history of breast cancer, with a Port-a-Cath reservoir implanted in the left pre-pectoral region. A chest computed tomography (CT) conducted for follow-up of her oncological disease with intravenous contrast medium administered via the left arm showed sclerotic lesions in several upper dorsal vertebrae, suggestive of bone metastases (Fig. 1A, B). The CT also revealed chronic thrombosis of the innominate vein carrying the port and collateral venous circulation that had developed in the anterior chest wall (Fig. 1C) and in the posterosuperior mediastium. Given the lack of chest pain, the chest CT was repeated without intravenous contrast, and the vertebral lesions seen in the previous study were not detected (nor were they seen in a dorsal spine magnetic resonance imaging (MRI) study performed a few weeks later), so the presence of vertebral bone lesions could be ruled out.

Fig. 1.

(A) Sagittal reconstruction of the chest CT with intravenous contrast medium showing focal sclerotic bone lesions in the posterior margin of the T2 and T3 vertebral bodies, mimicking vertebral metastases. Note the port catheter in the theoretical position of the thrombosed innominate vein (short vertical arrow) and the development of collateral venous circulation in the perivertebral veins (short horizontal arrows). (B) Sagittal reconstruction of the chest CT with intravenous contrast medium showing focal sclerotic bone lesions in the posterior margin of the T3 and T5 vertebral bodies (long arrows). Note the port catheter in the theoretical position of the thrombosed innominate vein (short arrow). (C) Maximum intensity projection axial reconstruction of CT, showing development of collateral venous circulation in the anterior chest wall (arrows).

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VEVC in patients with thrombosis of the central veins of the chest is a phenomenon rarely described in the scientific literature, although it has been documented mainly in patients with full or partial thrombosis of the SVC due to chest tumors (particularly in lung cancer), intravascular devices (pacemakers, ports), or mediastinal fibrosis.1 The venous collaterals that develop in cases of chronic SVC thrombosis in the tributary veins of the azygos/hemiazygos system include the intercostal, the intervertebral, and the basivertebral veins.2–4 Our case is of interest because the chronic thrombosis affected only the innominate vein and not the SVC, and the VEVC of the upper dorsal was caused by the retrograde reflux of intravenous contrast medium via the collateral basivertebral veins (due to the difficulty of draining to the SVC). As the basivertebral veins drain the most posterior part of the vertebral bodies, VEVC preferentially affects the posterior margin of the dorsal vertebrae.

We believe that VEVC should be considered by radiologists and physicians in patients with thrombosis of the proximal veins of the chest (not only the SVC), particularly in cancer patients in whom this phenomenon can mimic sclerotic vertebral lesions and lead to the wrong therapeutic management. If sclerotic vertebral metastasis is suspected in patients with VEVC, we recommend repeating chest CT without contrast or performing other additional studies (MRI of the spine or PET/CT) to confirm the real etiology of the vertebral sclerosis and to avoid further aggressive diagnostic procedures, such as bone biopsy.