Final answer:
The most important finding to report to the healthcare provider in a patient with chemotherapy-related neutropenia receiving filgrastim injections is a white blood cell count of 39,000 mm3.
Step-by-step explanation:
The most important finding to report to the healthcare provider in a patient with chemotherapy-related neutropenia receiving filgrastim injections is a white blood cell count of 39,000 mm3. Neutropenia is a condition characterized by a low neutrophil count, which increases the risk of infection. A white blood cell count of 39,000 mm3 indicates an abnormally high number of white blood cells, which could indicate an underlying infection or other complications.