thanks for ur query
ur bro has a lump on his upper gums with a white spot on it that is growing inspite of antibiotics clindamycin
was there any caries in it????
how was ur bro's oral hygiene????
i think in this age group its most probably a dental cyst
it needs to be examined properly to stamp it any specific type among 3 types of cyst we usually come across
take a digital x-ray of the upper jaw inclding maxilla
to know the actual position and attachment of the lump
do consult a maxillo-facial surgeon for better management
cancer in this age group is rare though it needs to be confirmed by FNAC or biopsy
my info i think ll be of help to you