Figure 2. A 48-year-old woman with invasive ductal carcinoma in the left breast and malignant lymph node classified due to increased fluorodeoxyglucose (FDG) uptake on positron emission tomography computed tomography (PET/CT). (A) Axial fat suppressed T1-weighted image reveals an internal mammary lymph node (arrow) in the third intercostal space with loss of fatty hilum. (B) Axial fat suppressed contrast enhanced T1-weighted image, the size of lymph node is short axis of 9 mm and long axis of 15 mm. (C) Diffusion weighted imaging shows a high-signal-intensity of lymph node (arrow). (D) Apparent diffusion coefficient map shows a low-signal-intensity (arrow). (E) Initial PET/CT reveals presence of focal FDG uptake in the same location of left internal mammary lymph node with a maximum standardized uptake value of 1.5 (arrow). (F) Four months later, there is a marked increased FDG uptake from 1.5 to 7.8 (arrow).