Intra-axial dermoid/epidermoid tumors of the brainstem in children.

BACKGROUND: Epidermoid and dermoid cysts are rare intracranial space-occupying lesions, which account for about 1% of all intracranial tumors; they are even rarer in the pediatric age group. Among the various locations, that inside the brain stem is quite exceptional (only 12 cases reported to date in the literature). We report two additional cases occurring in children, underlining their clinical characteristics, the difficulties faced in the diagnostic work-up, and the surgical treatment adopted (which consisted of removal of the cyst contents and partial resection of the cyst membrane, because of its adherence to the surrounding nervous and vascular structures).
METHODS: We report two cases of intraaxial dermoid/epidermoid cysts observed within the last 5 years. Both patients complained of cervico-nuchal pain, with a remittent/intermittent character in one of them; this patient also exhibited transient 6th and 7th cranial nerve deficit. One lesion was approached through the floor of the fourth ventricle, the second one through the ventrolateral aspect of the brainstem.
RESULTS: Subtotal tumor resection was achieved in both cases. Both patients had a smooth postoperative course without permanent neurological deficits. In the first patient residual tumor remains stable on follow-up MRI. In the second one, early tumor regrowth necessitated a second operation, after which the residual tumor has remained stable.
CONCLUSIONS: Based on our experience we suggest that a cautious surgical approach ("conservative" resection) to these lesions is the best choice. In fact, attempts at radical removal carry unacceptably high morbidity and mortality rates.