Thank you for asking Healthcare majic. My name is Dr Ehsan Ullah & I have gone through your query. you have mentioned about the Lump in the Nape of the neck. & along with that you have mentioned about shoulder pain There are Various Causes for this Lump depending upon Its Features you have mentioned the Size of it as Tennis Ball and its Not Painful. Most probably it s Lipoma which is a benign (Non dangerous) swelling/collection of the Fats Other causes can be enlarged occipital lymph node but those are usually a little higher than the position you mentioned Cysts whatever the nature of this lesion is All suspicious lumps require examination by the Physician with clinical examnation and you may need to have some Lab work up along with Radiological evaluation (Ultrasonography / X-Ray) For Shoulder pain , you Can use Over the counter available medications like Tab Tylenol. Hope this may help you. Let me know if anything not clear. Thanks.