Hematopoietic malignancies that can be encountered in the breast include lymphoma, leukemia, and multiple myeloma/plasmacytoma. These are readily imaged via [18]F-fluorodeoxyglucose position emission tomography (PET)/computed tomography (CT) and can manifest as unilateral, bilateral, single, multiple, round/oval masses, or diffuse. These malignancies can occasionally mimic primary breast cancers. Conversely, benign conditions, such as the lactating breast can resemble hematopoietic malignancies of the breast. Although uncommon, familiarity with hematopoietic malignancies of the breast is important for proper interpretation of PET/CT. In this pictorial review, the PET/CT imaging features of patients with hematopoietic malignancies of the breast will be described, including pathology-proven cases of acute myelogenous leukemia, diffuse B-cell lymphoma, follicular lymphoma, acute myeloid leukemia with neutropenic granulocytic) sarcoma, and plasmacytoma. In addition, potential pitfalls will be discussed.