Hi, Thanks for writing in. It is rare to find two different cancers in a patient but this is not unheard of. The possibility of chemotherapy for follicular lymphoma causing breast cancer is less. However there is a slight chance of cancer in the breast if you have received radiation therapy for your previous cancer. There are studies which have shown that radiation therapy for lymphoma might put the patient at slight risk of another cancer. However, since there is no obvious mass in the breast refion therefore the likelihood of a cancer is less. Since there is a suspicious finding on mammography therefore confirming it with ultrasound is important. Please do not worry.