Abstract Chronic myelomonocytic leukemia (CMML) is a myelodysplastic/myeloproliferative neoplasm characterized by the infiltration of blood and bone marrow by immature monocytes, in which extra‐hematopoietic localization is uncommon. We report the case of a 69‐year‐old‐man with highly likely ectopic brain CMML involvement by MRI. Without the possibility of cerebral biopsy and with a negative infectious disease assessment, high‐dose cytarabine‐based chemotherapy was successfully administered. The favorable evolution in this case highlights the potential benefit of such treatment, even without a cerebral biopsy to confirm the disease. This case can aid clinical decision‐making in the future.
