經篩骨之腦膜腦膨出─病例報告

Differential diagnosis of intranasal masses in children consists mainly of congenital tumors and developmental anomalies. Among the latter, meningoencephalocele, nasal glioma and dermoid cyst should be ruled out before straightforward biopsy to avoid the formidable outcome of CSF rhinorrhea and meningitis.
We encountered a 30-month-old female child presenting with left intranasal mass, nasal pain and persisting watery rhinorrhea for 15 months. Telecanthus and flattened nasal ridge were noted while no neurologic abnormality was found. Magnetic resonance image of the brain showed a pedunculated nasal mass connecting with the frontal lobe through the cribriform plate. The mass hung over the left nasal roof and was glistening-white in color and soft to the touch under endoscopic examination. The patient underwent bifrontal craniotomy and intranasal tumor resection. A bony defect measuring about 0.6 cm×0.8 cm in diameter was identified, through which the herniated brain tissue passed to the nasal cavity. After dividing the herniated tissue, the dura was repaired and the bony defect was obliterated. Postoperative course was uneventful with no evidence of recurrence.
The tumor was histologically characterized by numerous astrocytic neuroglial cells interspersed among neurofibrillary ground. Some fibrovascular tissue was noted while no mitosis was documented. Though pathologic pictures offered no clues in differentiating meningoencephalocele from nasal glioma, the final diagnosis was made on the basis of clinical history, physical examination, MRI and operative findings, which were discussed elaboratively in the text.