This kind of bump can be a swollen lymph node,a sebaceous cyst or a benign tumor. Lymphadenopathy (swollen lymph nodes) is usually caused by a viral or bacterial infection along with other numerous causes.Treatment is usually cold compresses,over the counter anti-inflammatory analgesics(pain killers) like acetaminophen or ibuprofen,antibiotics if cause of infection is suspected to be a bacteria and surgical drainage if there is any abscess formation.
Sebaceous cyst is a closed sac or cyst below the surface of the skin that has a lining that resembles the uppermost part (infundibulum) of a hair follicle and fills with a fatty white, semi-solid material called sebum produced by sebaceous glands of the epidermis.It is usually painless but can become painful if infected.Then antibiotics are needed.
If the symptoms worsen or the lump starts growing in size or becomes painful,then pls get it evaluated from a physician.I sincerely hope that helps. Please do keep me posted. Kind regards.