Mollaret Meningitis Associated with Occipital Dermal Sinus
Article Outline
A 1-month-old female infant was referred with vomiting and fever. The cerebrospinal fluid (CSF) showed a pleocytosis (291 cells/mm3). Peripheral blood demonstrated leukocytosis (17 000/mm3) and high value of C-reactive protein (1.19 mg/dL). The culture results of CSF were negative. The patient was treated with antibiotics, and the symptoms resolved within 48 hours. One month later, she manifested a second episode of meningitis with pleocytosis in CSF (2506 cells/mm3). She was treated with antibiotics and dexamethasone, resulting in the resolution of meningitis within 24 hours. Staphylococcus aureus was detected by the culture of CSF. The cytologic study of the CSF revealed neutrophils, lymphocytes, and large macrophage-like unique cells with foamy abundant cytoplasm and bean-shaped nuclei (Figure 1; available at www.jpeds.com). A magnetic resonance imaging scan revealed a dermoid cyst with occipital dermal sinus (ODS) (Figure 2). A plain radiograph and CT showed a marked defect in the occipital skull vault (Figures 3 and 4; available at www.jpeds.com). With a diagnosis of ODS, a surgical excision of the lesion was performed. At 15 months after surgery, the patient remains asymptomatic.
Figure 2
Cranial magnetic resonance imaging: Sagittal view, T2-weighted (left), and Gd-enhanced T1-weighted (right) images show the cystic mass of posterior fossa with the sinus tract extending from the skin dimple.
Mollaret meningitis (MM) consists of recurrent episodes of aseptic meningitis. The CSF showed pleocytosis with neutrophils, lymphocytes, and monocytes.1 In particular, an abundance of large monocytoid cells with unique nuclear shapes is characteristic feature of MM. The etiology of MM is unknown, but the association between MM and dermoid-epidermoid cysts has been reported.2, 3, 4 ODS is frequently accompanied with dermoid cysts and may be also associated with MM, resulting from episodic release of aseptic dermoid material from the cyst into CSF space.5 No relapses occurred since the removal of ODS, so we hypothesize that the local infection in ODS may contribute as a trigger to meningitis in this case. The differential diagnosis of recurrent meningitis should include MM with occipital dermal sinus. Cytopathologic analysis of CSF and neuroimaging studies should be performed.
Figure 1
Cytologic study of CSF: Unique, large, macrophage-like cells with foamy abundant cytoplasm and bean-shaped nuclei are shown.
Figure 3
Plain radiograph, frontal view, shows a marked defect in the occipital skull vault.
Figure 4
Three-dimensional CT scan shows a defect in the occipital skull vault.
References
- . Mollaret's meningitis: cytopathologic analysis of fourteen cases. Diag Cytopathol. 2003;28:227–231
- . Recurrent aseptic meningitis secondary to intracranial epidermoid cyst and Mollaret's meningitis: two distinct entities or a single disease? A case report and a nosologic discussion. Am J Med. 1990;89:807–810
- . Central nervous system epidermoid cyst: a probable etiology of Mollaret's meningitis. Am J Med. 1990;89:805–806
- . Mollaret's recurrent aseptic meningitis and cerebral epidermoid cyst. Pediatr Neurol. 1998;18:156–159
- . Occipital dermal sinuses: report of nine pediatric cases and review of the literature. Pediatr Neurosurg. 2001;34:255–263
PII: S0022-3476(09)00486-7
doi:10.1016/j.jpeds.2009.05.011
© 2009 Mosby, Inc. All rights reserved.
Refers to erratum:
- Erratum
- Correction
