Detection of a mammographically occult invasive lobular breast carcinoma by PET/CT in a patient with lymphoma.

We present a case of invasive lobular breast carcinoma which was detected incidentally by positron emission tomography/computed tomography (PET/CT) in a patient with lymphoma, although occult on the subsequent mammogram. This 60-year-old female, with a history of non-Hodgkin lymphoma, underwent PET/CT imaging for routine follow-up which demonstrated a new hypermetabolic focus in the right breast suspicious for malignancy. Further workup showed no mammographic abnormality, but ultrasound-guided biopsy demonstrated this to be an unsuspected primary breast carcinoma. This case indicates that evaluation of the breasts is important to include in PET/CT interpretation, and abnormalities should be diligently pursued despite lack of mammographic correlation.