Suggest Treatment For Painful Raised Skin On Chest

Hi, my mom aged 45-50 yrs developed skin pop up on her skin. She says it started paining. It is of marble shape. like cotton if we touch it. she has other 2 or 3 on her chest.they are now started and are painful we press them. MY mom is diabetic and she is 55 kgs. she takes medicines Daonilm and ALL-LOW