Intracerebral atypical hemorrhages mimicking metastases in a patient with breast cancer history: diagnostic challenges and key insights. Illustrative case.

BACKGROUND: Intracerebral hemorrhage (ICH) in cancer patients may reflect hypertension, vascular malformations, coagulopathy, or hemorrhagic metastases. Differentiating atypical hemorrhages from brain metastases is diagnostically challenging, particularly in patients with prior breast cancer. OBSERVATIONS: The authors describe the case of a 67-year-old female with a history of breast cancer who presented with a first generalized seizure and bifrontal headache. Imaging revealed atypical bilateral ICHs in the right frontal and left occipital lobes, without trauma or anticoagulation. CT and MRI findings favored subacute hemorrhage without enhancement. Given the patient's oncological history, surgery with biopsy was performed to exclude metastasis. Histopathological analysis revealed only organized hemorrhage, with no tumor cells or vascular malformation. The patient recovered well after craniotomy. The authors are not aware of previous reports of 2 atypical ICHs in the frontal and occipital lobes in a patient with a history of cancer, without trauma, and without blood-thinning drugs. LESSONS: Atypical bilateral ICH in a breast cancer patient may mimic metastases. In such cases, biopsy and histological analysis are mandatory to guide treatment. Correct differentiation avoids overtreatment and enables tailored management. https//thejns.org/doi/10.3171/CASE251001.