<s>[INST] hi im 22 years old and I have a lump on my sternocleidomastoid muscle, its golfball sized and seems hard. I have a few others, one that s behind my ear and the area around my clavicle feels very swollen. This all came on within days. I don t know what to do. [/INST] Hi, dairy have gone through your question. I can understand your concern. You may have enlarged lymph nodes. It can be due to reactive hyperplasia, tuberculosis, lymphoma or metastatic carcinoma. You should go for fine needle aspiration cytology or biopsy of that lump. It will give you exact diagnosis. Then you should take treatment accordingly. Hope I have answered your question, if you have any doubts then contact me at bit.ly/ Chat Doctor. Thanks for using Chat Doctor. Wish you a very good health </s>