Lump at back of neck can have various causes, ranging in severity from 'serious' to 'generally fatal'. Finding the true cause means ruling out or confirming each possibility – in other words, diagnosis.
Diagnosis is usually a complex process due to the sheer number of possible causes and related symptoms. In order to diagnose lump at back of neck, we could:
BACK OF NECK: Do you have any swollen or tender lymph nodes here?
Possible responses:→ Don't know
→ Yes, swollen but not tender
→ Yes, tender but not swollen
→ Yes, swollen and tender
The most common symptom of non-Hodgkin's lymphoma is a painless swelling of the lymph nodes in the neck, underarm, or groin.