Skull infarction and chronic subdural exudates in a pediatric patient with sickle cell anemia: illustrative case.

backgroundSkull infarction is a rare sickle cell disease (SCD) complication. While epidural hematomas from calvarial infarction have been sporadically reported, subdural collections and sterile exudates mimicking intracranial empyema remain poorly characterized. OBSERVATIONS: A 6-year-old boy with nonverbal autism and SCD presented with progressive periorbital swelling, fever, and extremity pain. CT raised concern for orbital cellulitis, subperiosteal abscess, and subdural empyema. MRI revealed a diffuse heterogeneous calvarial marrow signal with multifocal nonenhancement and restricted diffusion consistent with bone infarction, alongside right convexity subdural fluid and bilateral epidural and subperiosteal rim-enhancing collections demonstrating susceptibility artifacts. Emergency craniotomy and orbital exploration yielded hemosiderin-stained fluid, and necrotic bone without purulence. All operative cultures were negative. Postoperative imaging demonstrated expansion of the subdural collection to 8 mm with 6-7 mm of midline shift, managed with dexamethasone. Nine months later, the patient re-presented with recurrent subperiosteal hemorrhage without infection. LESSONS: Calvarial infarction in SCD can produce sterile collections that mimic infectious processes. Intraoperative findings and culture data are essential in distinguishing these entities. Middle meningeal artery embolization warrants caution in SCD patients, given the risk of moyamoya vasculopathy. This case underscores the importance of a broad differential when evaluating SCD patients with periorbital swelling and intracranial collections. https://thejns.org/doi/10.3171/CASE26291.