Occipital Intradiploic Pseudomeningocele: a rare complication of pediatric posterior cranial fossa surgery. Case Report and Review of the Literature

Introduction: Intradiploic pseudomeningoceles, also called intradiploic cerebrospinal fluid (CSF) fistulas, are abnormal CSF collection between the two bony tables of the calvaria resulting from post-surgical CSF leakage. To date, only six cases of intradiploic pseudomeningocele have been reported, all occurring in the occipital area.In this paper, we report the seventh case of late-onset occipital intradiploic pseudomeningocele (OIP) occurring in a young female patient who underwent surgery for the removal of a cerebellar pilocytic astrocytoma. At this regard, we also review the literature on the few recognized cases of OIP.Case presentation: The case of an 18-year-old female patient known to our institute for an operation 12 years earlier to remove a pilocytic astrocytoma is illustrated. At admission the patient complained only of occasional orthostatic headache. Brain imaging demonstrated a pseudomeningocele extended intradiploically from the occipital squama to the condylar and clivus regions, thinning both occipital bone tables and dilating the CSF-filled diploe. Watertight duroplasty and cranioplasty were effectively performed.Conclusion: Pediatric patients undergoing posterior cranial fossa craniotomy/craniectomy may postoperatively develop OIP. In this setting, treatment of any dural CSF fistula should be considered because of the risk of progressive extension and bone erosion.