Spontaneous Rupture of a Fourth Ventricular Mature Teratoma Presenting with Aseptic Meningitis in a 10-Year-Old: A Rare Case from Rural Kenya

Abstract

Intracranial teratomas are rare, accounting for <0.5% of primary brain tumors, with mature teratomas representing the benign form. Spontaneous rupture with intrathecal dissemination of lipid-rich material is exceedingly uncommon, particularly in the fourth ventricle. We report the case of a 10-year-old girl presenting with a six-month history of generalized tonic-clonic seizures, followed by acute headaches, vomiting, and neck pain. CT imaging revealed obstructive hydrocephalus, fat-fluid levels in the ventricles, and a heterogeneous fourth ventricular lesion consistent with a ruptured teratoma. Cerebrospinal fluid was clear with negative cultures, supporting a diagnosis of aseptic (chemical) meningitis secondary to intrathecal fat dissemination. An external ventricular drain was placed for temporal CSF diversion, during which fat globules were noted. Gross total resection of the lesion was achieved via a telovelar approach, with intraoperative findings of a lipid-rich tumor occupying the fourth ventricle. Histopathology confirmed a mature teratoma, composed of ectodermal, mesodermal, and endodermal derivatives without immature elements. No adjuvant chemotherapy or radiotherapy was administered. The patient made an uneventful recovery, with complete resolution of symptoms and no recurrence at three months follow-up. Long-term monitoring with interval neuroimaging is planned, given the risk of recurrence or obstructive hydrocephalus from residual fat. This case underscores the diagnostic significance of intraventricular fat-fluid levels on imaging, which are pathognomonic for ruptured teratoma. Gross total resection remains the cornerstone of management, and the telovelar approach is particularly advantageous for fourth ventricular lesions. To our knowledge, this is the first reported case of a spontaneously ruptured fourth ventricular mature teratoma presenting with aseptic meningitis in rural Africa. Conclusion: Prompt recognition and complete surgical excision of ruptured mature teratomas can achieve excellent outcomes, even in resource-limited settings.