Azygos Venous Tumor Thrombus From Renal Cell Carcinoma Detected by F-18 FDG PET/CT

Abstract

An 81-year-old woman with renal cell carcinoma (RCC) underwent F-18 FDG PET/CT for staging, which demonstrated intense uptake in a dilated azygos vein, in the inferior vena cava (IVC), and in the known large left RCC. Contrast-enhanced CT of the chest and abdomen obtained in the days following confirmed the presence of tumor thrombus in the dilated azygos system, IVC, and the contiguous left renal vein. This case serves as a reminder that special attention should always be paid to the renal vein, IVC, and adjoining venous drainage pathways for abnormal FDG activity while imaging RCC, as the diagnosis of venous tumor thrombus has important clinical ramifications.

Role of FDG PET-CT in Distinction of Benign Thrombus and Tumor Thrombus in Oncological Patients

“…TT is mostly an insidental finding in CECT. Tumor thrombus is rarely seen in solid tumors such as mostly in hepatocellular carcinoma (ca) and renal cell ca, followed by ovarian/testicular tumors, colon ca, pancreas ca, lung, breast, thyroid tumors, lymphomas, sarcomas, neuroendocrine tumors [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Maximum standardized uptake value (SUVmax) is semiquantitative parameter that reflect metabolic activity, but is not specific marker of malignancies.…”

Potential Role of FDG PET/CT Imaging for Assessing Venous Thromboembolic Disorders

“…20,23Y26 Up until now, detection of thrombosis with FDG-PET/CT has been sporadically reported, mostly as an incidental finding in various malignancies including lymphomas, melanomas, renal cell carcinomas, and hepatocellular carcinomas. 24,27,28 In addition, small patient series have evaluated FDG-PET/CT for discriminating between tumor thrombosis and VTE, 29Y31 and case studies have illustrated the use in sagittal sinus thrombosis. 32,33 Some have suggested that only tumor-related or tumorinfected thrombi are FDG avid, whereas others including our own group are of the opinion that specific cells in the clots are responsible for the observation.…”

Azygos vein thrombosis despite rivaroxaban therapy in a patient with breast cancer: A rare entity

“…Azygos vein thrombosis (AVT) is an extremely rare type of venous thromboembolism. It is commonly associated with predisposing factors such as azygous vein aneurysm and malignancy including cholangiocarcinoma 1 and renal cell carcinoma 2 . However, AVT associated with metastatic breast cancer has not been reported yet.…”