Rectal dural metastasis masquerading as chronic subdural hematoma: illustrative case

BACKGROUND: Intracranial dural metastasis causing subdural hematoma formation is a rare clinical entity associated with significant morbidity and mortality. A 61-year-old female patient known to have rectal signet ring cell carcinoma presented with cranial computed tomography scan findings of bilateral subdural hematoma. She underwent evacuation of the hematoma with dural biopsy, which showed tumor emboli consistent with colorectal origin. There was an early recurrence of the subdural collection, and an emergency subdural-peritoneal shunt insertion was done; however, there was no sustained clinical improvement. This work reports the first case of rectal dural metastasis presenting as chronic subdural hematoma and discusses the clinical course and current literature. OBSERVATIONS: The cases described in these studies are consistent with the clinical course of our patient; that is, evacuation of the subdural hematoma provided temporary clinical improvement and re-accumulation occurred within 3 days. LESSONS: The authors recommend maintaining a high index of suspicion in this select group of patients, including prompt discussion about treatment plans with the patient’s family.