Incidental focal uptake in the breast and axilla on FDG PET: Clinical considerations and differential diagnosis.

Incidental focal FDG uptake in the breast or axilla on PET/CT performed for evaluation of extra-mammary primary disease presents a diagnostic challenge. Radiologists must consider a broad differential diagnosis, assess clinical history, and judiciously employ other imaging modalities such as mammography, ultrasound and MRI in the pursuit of findings which help narrow the differential diagnosis. Tissue sampling may be reserved for nondiagnostic imaging scenarios.