Such kind of lump can be a swollen lymph node, sebaceous cyst or a benign skin growth. Lymphadenopathy (swollen lymph nodes) is usually caused by a viral or bacterial infection along with other numerous causes. Sebaceous cyst is below the surface of the skin that fills with a fatty white, semi-solid material called sebum produced by sebaceous glands of the epidermis.
I suggest you to get it examined from a dermatologist for these possibilities.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.