<s>[INST] My wife has a lump that has appeared just below the skull on the back of her neck just to the left of the spinal column. It is about golf ball size and she has had a on again off again headache occurring all week. She say's the lump appeared about 3 weeks ago. what are your suggestions. [/INST] Dearthanks for sharing with us your query.It difficult to find the cause with that lump without examination.First two examination you should do are blood tests and an ultrasound of the neck region.After the result perhaps a cervical MRI need to be done!You have to worry but no too much, it can be even from a dental infections so no need for alarm but examinations need to be done.Hope I had helped you Dr Eris </s>