Facial venous tumour thrombus from submandibular gland mucoepidermoid carcinoma: an atypical tumour spread in head and neck cancer

Tumours of head and neck may cause thrombosis of veins by direct invasion resulting in a tumour thrombus, or indirectly by exerting a mass effect and vein compression.These can be distinguished by contrast-enhanced computed tomography (CECT) or magnetic resonance imaging (MRI).Doppler ultrasound may show patchy neovascularisation in a tumour thrombus, which would be absent if thrombosis was caused by compression.