A 55-year-old, previously healthy woman received a diagnosis of diffuse large-B-cell lymphoma after the evaluation of an enlarged left axillary lymph node obtained on biopsy. She had been asymptomatic except for the presence of enlarged axillary lymph nodes, which she had found while bathing. She was referred to an oncologist, who performed a staging evaluation. A complete blood count and test results for liver and renal function and serum lactate dehydrogenase were normal. Positron-emission tomography and computed tomography (PET–CT) identified enlarged lymph nodes with abnormal uptake in the left axilla, mediastinum, and retroperitoneum. Results on bone marrow biopsy were normal. The patient’s oncologist recommends treatment with six cycles of cyclophosphamide, doxorubicin, vincristine, and prednisone with rituximab (CHOP-R) at 21-day intervals. Is the administration of prophylactic granulocyte colony-stimulating factor (G-CSF) with the first cycle of chemotherapy indicated?