Multifocal hemorrhagic metastases with cerebellar predominance following prolonged remission of pancreatic adenocarcinoma: illustrative case.

backgroundBrain metastases from pancreatic adenocarcinoma are extremely rare, particularly when involving the cerebellum or presenting with atypical dural or hemorrhagic lesions. Only 2 other reported cases demonstrate multifocal brain metastases with cerebellar involvement following remission of pancreatic cancer. OBSERVATIONS: A 55-year-old man with stage IV pancreatic ductal adenocarcinoma and liver metastases achieved systemic remission following chemotherapy and chemoradiation therapy. Brain MRI 1 year postdiagnosis was negative for metastases. Twenty-seven months postdiagnosis, he developed headaches and an ataxic gait, with imaging revealing multifocal hemorrhagic brain metastases with no evidence of systemic extracranial disease. The cerebellar lesion was resected via suboccipital craniotomy, followed by fractionated stereotactic radiotherapy targeting the resection cavity and remaining supratentorial lesions. Despite neurological recovery postcraniotomy, the patient died 4 months later due to rapid extracranial progression. A literature review of cerebellar metastases from pancreatic cancer reveals only 3 patients surviving beyond 24 months, while the median survival for patients who died was approximately 50 days. LESSONS: In patients who achieve pancreatic cancer remission considering systemic therapy de-escalation, clinical vigilance remains essential. Lingering brain metastases may remain resistant and signal rapid decline, particularly in aggressive cerebellar lesions. Targeted surgical and radiosurgical approaches support the potential for individualized, lesion-specific therapy. https://thejns.org/doi/10.3171/CASE25624.