[Brain stem tumors associated with neurofibromatosis type 1. Presentation of 20 infantile patients]
I Pascual Castroviejo1, Si Pascual Pascual, R Velázquez Fragua
1Servicio de Neurología Pediátrica. Hospital Universitario La Paz. Madrid, Spain. i.pcastroviejo@neurologia.e.telefonica.net
Objective:
To describe the clinical and imaging findings of 20 patients (12 women and 8 men) with brain stem tumors associated with neurofibromatosis type 1 (NF1).
Patients And Methods:
All patients were first time studied before 11 years old. Clinical and magnetic resonance (MR) study were made in all 20 patients, and spectroscopic MR (SMR) was performed in 7 patients. Thirteen of the 20 patients (65 %) also had optic pathway tumor. Brain stem tumor identification occurred at the same time as NF1 in the patients who were studied by MR at the time of the first consult.
Results:
Brain stem identification occurred at the same time as that of the NF1 in patients who were studied by MR from the beginning. Diffuse or localized medullary enlargement was the most frequent MR imaging and appeared in 13 patients (65%), followed by the tumor that involved all brain stem (pontine and medullary areas) that appeared in 6 patients (30 %). In the last group, one tumor showed extension through brain stem and medial cerebellar parts, another was located in the aqueduct and in the periaqueductal areas and showed slow progressive growth, and one third patient had a tumor with aggressive signs in the SMR study. Another patient had an aggressive tumor that involved the left optic nerve, chiasm, mesencephalon and upper right pontine areas. The histological study of the tumoral biopsic tissue of the two last patients showed astrocitoma degree 1 (benign tumor). The two aggressive tumors were treated with radiotheraphy and chemotherapy and they are still alive 4 and 7 years respectively after treatment. Three patients who had aqueductal obstruction and hydrocephalus were treated with shunt. The rest of patients did not receive treatment. Only one of the 20 patients died, although it was due to a malignant chiasmatic tumor, that had been treated twenty years before, and not by the brain stem tumor.
Conclusions:
In NF1, brain stem tumors are the most frequent tumors of the posterior fossa and the second most frequent of the central nervous system (CNS). MR and SMR are necessary to a correct identification of the tumor in some patients. Most of these tumors are benign.
