Waqas Ahmad ( Department of Radiology, Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan. )
Namra Asghar ( Department of Nuclear Medicine, Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan )
Tehreem Zafar ( Department of Radiology, Shaukat Khanum Memorial Cancer Hospital and Research Center Lahore, Pakistan )
Humayun Bashir ( Department of Nuclear Medicine, Shaukat Khanum Memorial Cancer Hospital & Research Center, Lahore, Pakistan. )
Tumour thrombus is an uncommon complication with ominous outcomes. F18 FDG PET-CT scan helps in differentiating tumour thrombus from venous thrombus owing to its metabolic uptake similar to the tumour. We discuss an interesting case of gastric malignancy with complete splenic vein tumour thrombosis on initial presentation.
Keywords: Splenic vein thrombus, gastric tumour, F18–FDG-PET-CT
A 48 years-old-male presented with weight loss and dysphagia for two months. Initial CT showed large gastro-esophageal mass involving left diaphragmatic crus with locoregional lymphadenopathy. Biopsy revealed poorly differentiated adenocarcinoma. Baseline CT showed locally advanced gastric tumour with complete splenic vein thrombosis (Figure-1).
PET/CT demonstrated increased metabolic activity in the primary gastroesophageal junction tumour with hypermetabolic locoregional; peri-gastric nodes - SUV of 8 (Figure-2).
In addition, PET-CT scan revealed hypermetabolic complete splenic vein thrombus - SUV of 6.3 (Figure-3) confirming tumour thrombus.
Tumour thrombus is a rare complication of solid tumours depicting poor prognosis.1 In literature, only a few cases of tumour thrombus in portal vasculature secondary to gastric cancer have been reported till now. Tumour spread in the portal circulation is mainly due to gastric venous drainage pathways.2 It is important to differentiate between tumour thrombus and venous thromboembolism (VTE) in cancer patients, as they have different treatment strategies.1 Many small series have shown the superiority of F18 FDG PET-CT scan in diagnosing tumour thrombi. These typically appear as linear or focal FDG uptake noted in vessels with elevated maximum standardized uptake values.3 Heterogeniety in FDG uptake pattern probably reflect variations in the density of neoplastic cells in thrombus.4 FDG PET-CT scan using dual time point imaging protocol may also play an important role in diagnosing tumour thrombus in oncological patients and thereby help guiding treatment appropriately.
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2. Barıs O,Çevener M, Kargı A, Mustafa O,Gurkan A. Isolated Superior Mesenteric Vein Tumor Thrombus in a Patient with Gastric Cancer. Case Reports in Surgery.2018pages1-5 Article ID 3648436, doi: 10.1155/2018/3648436
3. Sonavane SN, Malhotra G, Asopa R, Upadhye T. Role of fluorine-18 fluorodeoxyglucose positron emission tomography in a case of renal cell carcinoma to differentiate tumor thrombus from bland thrombus. Indian J Nucl Med. 2015;30: 355-357.
4. Ravina M, Hess S, Chauhan MS, Jacob MJ, Alavi A.Tumor thrombus: ancillary findings on FDG PET/CT in an oncologic population. Clin Nucl Med. 2014;39: 767-771.