When extracerebral cancer can cause headache or facial pain
Extracranial cancers can cause headache by several mechanisms. Tumors of the neck and mediastinum compressing or invading major venous drainage pathways, such as the jugular veins or superior vena cava, can increase intracranial pressure due to venous outflow compromise. Systemic malignancies can also induce hypercoagulable states and subsequent venous sinus thrombosis, producing increased intracranial pressure and possibly decreased levels of consciousness. Extracranial tumors can also cause referred pain due to compression of adjacent neurovascular structures. For example, sinonasal and facial tumors can stimulate or invade the trigeminal nerve to cause referred head pain. Similarly, upper cervical masses compressing the nerve roots can cause posterior fossa pain and headache.