Unusual intracranial suppuration: illustrative cases

BACKGROUND Intracranial suppuration (ICS) is a rare complication that can arise from various disease processes and is composed of brain abscess, extradural empyema, and subdural empyema. Although significant progress has been achieved with antibiotics, neuroimaging, and neurosurgical technique, ICS remains a serious neurosurgical emergency. An uncommon presentation of ICS is sterile ICS, which has yet to be fully elucidated by clinicians. The authors present 2 cases of unusual sterile ICS: a sterile subdural empyema and a sterile brain abscess. OBSERVATIONS Both patients underwent surgical treatment consisting of craniotomy to evacuate the pus collection. The blood cultures from both the patients, the collected empyema, and the thick capsule from the brain abscess were sterile. However, the necrotic brain tissue surrounding the abscess contained inflammatory cells. The authors’ review of the literature emphasizes the rarity of sterile ICS and substantiates the necessity for additional studies to explore this field. LESSONS Sterile ICS is a disease entity that warrants further investigation to determine appropriate treatment to improve patient outcomes. This study highlights the paucity of data available regarding sterile ICS and supports the need for future studies to uncover the etiology of sterile ICS to better guide management of this condition.