Jugular foramen schwannoma: A rare tumor treated by stereotactic radiosurgery

Jugular foramen schwannomas (JFS) are rare benign tumors located in the jugular foramen. They can present with various symptoms depending on the extent of involvement of the tumor such as hearing loss, tinnitus, headache, and ataxia. Surgical resection has been considered as the primary treatment option for JFS. Stereotactic radiosurgery (SRS) offers an equally good treatment in patients with small and residual tumors after surgery with the advantage of being non-invasive with minimal complication rates. Herein, we present a rare case of JFS treated by SRS in our institution.

Expression of the neurotrophin receptors Trk A and Trk B in adult human astrocytoma and glioblastoma.

Neurotrophins and their receptors of the Trk family play a critical role in proliferation, differentiation and survival of the developing neurons. There are reports on their expression in neoplasms too, namely, the primitive neuroectodermal tumours of childhood, and in adult astrocytic gliomas. The involvement of Trk receptors in tumour pathogenesis, if any, is not known. With this end in view, the present study has examined 10 tumour biopsy samples (identified as astrocytoma, pilocytic astrocytoma and glioblastoma) and peritumoral brain tissue of adult patients, for the presence of Trk A and Trk B receptors, by immunohistochemistry. The nature of the tumour samples was also confirmed by their immunoreactivity (IR) to glial fibrillary acidic protein. In the peritumoral brain tissue, only neurons showed IR for Trk A and Trk B. On the contrary, in the tumour sections, the IR to both receptors was localized in the vast majority of glia and capillary endothelium. There was an obvious pattern of IR in these gliomas: high levels of IR were present in the low-grade (type I and II) astrocytoma; whereas in the advanced malignant forms (WHO grade IV giant cell glioblastoma and glioblastoma multiforme) the IR was very weak. These findings suggest that Trk A and Trk B are involved in tumour pathogenesis, especially in the early stage, and may respond to signals that elicit glial proliferation, and thus contribute to progression towards malignancy.