Mayo symptom is a manifestation of an anatomical defect in the head region, manifested by subcutaneous lymphangitis and lymphadenopathy along the occipital veins and the vein flowing into the transverse occipital sinus. This symptom is pathognomonic for thrombophlebitis of the occipital branch of the left internal jugular vein (phlebothrombosis). Mayo was a Canadian surgeon who introduced the symptom named after him in 1898. He described this phenomenon when he discovered a large tumor located behind the pinna of a patient's neck.
When he examined this tumor, he discovered that it was associated with thrombosis of the posterior superior cerebral vein. The Mayo sign manifests itself as subcutaneous lymphadenitis or lymphadenopathy when examining the back of the head. This leads to symptoms of lymph node hypertrophy. There is an opinion that this symptom is not the earliest sign of cerebral hemorrhage. The appearance of pulsation and tenderness of the occipital lymph nodes in this situation may precede headaches by several days.