Hello, Doctor. I'm 15 years old. Weight is 101 KG, height is 5.5/5.6 inch. For last 3-4 months, I have a lump on the right-sided inner cheek. It was appear suddenly, in fact, overnight. I have attached the picture of this affected area. It is the picture of present time, in fact, today and newly taken. The day before when I first feel it, I noticed nothing in this area. So, I think it had developed overnight. However, in the first few days, the lump was painful and more larger than the picture attached (it is the picture of present time). Then I start taking Flucloxacillin 500 MG (twice/third a day and continue it for 10-14 days almost). Then, the pain got away and the swelling also reduced a bit but the swelling wasn't fully gone. Since then, I think that the lump is decreasing in size quite slowly. I have no other problem (like trouble eating or drinking) till now. Is it something serious like cancer, doctor?