hi this is Dr.subhadeep.thanks for the opportunity to help you.
as per your description of swelling it is fitting the diagnosis of
lipoma or sebaceous cyst.as it is difficult for you to confirm its location it is advisable to show to your
general surgeon and follow his advise.still I will guide you :-
1) if it is a neurolipoma causing pain then you can get it surgically removed.as the size is small so it won't take much time.it will be a minor surgery and your surgeon can decide about
biopsy.you can leave it also if your surgeon after examining you clinically confirms lipoma.
2)if it is a sebaceous cyst excision has to be done otherwise it will get infected and form
abscess.
there can also be a possibility of papilloma,evolving abscess from a pre-existing
haematoma etc.
if papilloma excision biopsy is ideal.
if evolving abscess then initially higher antibiotic coverage.rarely it may totally resolve.normally the abscess localizes and small I and d is perfect.
an USG of the gluteal region or FNAC from the swelling as per the surgeon's advise will be ideal.is there any discharge from the swelling?
kindly let me know if the consultation was beneficial.
regards