Innervation of the brain, intracerebral Schwann cells and intracerebral and intraventricular schwannomas.

The cerebral vasculature and the choroid plexus are innervated by peripheral nerves. The anatomy of the vascular supply to the brain and its related perivascular nerves is reviewed. Intracerebral and intraventricular schwannomas most likely come from neoplastic transformation of Schwann cells investing the perivascular nerves and nerves within the choroid plexus.

Well-differentiated pediatric glial neoplasms with features of oligodendroglioma, angiocentric glioma and dysembryoplastic neuroepithelial tumors: a morphological diagnostic challenge.

OBJECTIVE: Oligodendrogliomas are rare in the pediatric population, and most oligodendroglioma-like tumors in this age group may belong to other entities. In addition, accurate diagnosis and grading of such lesions using criteria developed for adult oligodendrogliomas prove difficult, and often controversial. MATERIAL AND METHOD: During a study of tumors previously diagnosed as pediatric oligodendroglioma, we identified four tumors displayed features of that resembled oligodendroglioma, angiocentric glioma and dysembryoplastic neuroepithelial tumor but could not be classified as either one of these entities. Ther clinical, histological and immunohistochemical features of these cases were investigated in this study. RESULTS: Two male (both 9 years old) and two female (ages 4 years and 20 months) patients presented with new onset of seizures. All patients were treated surgically, and two required reoperation. Histologically, the tumors were well-differentiated glial neoplasms with focal angiocentric pattern, delicate vascularity, diffuse growth, infiltrative margins, cortical nodules, focal myxoid areas, and leptomeningeal extension. Immunohistochemical studies showed diffuse nuclear positivity with Olig-2 and GFAP antibodies, whereas staining with neuronal markers, EMA, p53, and IDH1 were negative. Fluorescent in-situ hybridization analysis demonstrated intact 1p/19q in all tumors, and there was no ultrastructural evidence of ependymal differentiation. All patients were alive with disease with a mean follow-up of 112 months. CONCLUSION: These four cases illustrate the morphological diversity of well-differentiated, oligodendroglioma-like glial neoplasms and the uncertainty in their classification among pediatric tumors.

Spinal cord oligodendroglioma with 1p and 19q deletions presenting with cerebral oligodendrogliomatosis.

Oligodendroglioma of the spinal cord is a rare tumor that most often presents with spinal cord symptoms. The authors present a case of spinal cord oligodendroglioma that was associated with cerebral rather than spinal cord symptoms. A 30-year-old woman developed nausea, vomiting, and severe headaches. Magnetic resonance imaging of the brain showed meningeal enhancement. The patient underwent a craniotomy with biopsies of the meninges and brain. The biopsy findings revealed an abnormal arachnoid thickening without tumor cells. The patient later developed hydrocephalus and underwent shunt placement. Cerebrospinal fluid cytological findings were negative for tumor cells or infection. She was found to have a cervical cord lesion at C3-4 that was initially nonenhancing but later enhanced after Gd administration. Biopsy of the cord lesion with partial resection showed a WHO Grade II oligodendroglioma with 1p and 19q deletions determined by fluorescence in situ hybridization. Neurooncological treatment with tumor radiation and temozolomide (Temodor) resulted in improvement in radiographic findings, symptoms, and long-term survival. This paper presents an extensive review of the literature, which revealed only 2 other reported cases of cerebral symptoms in adults that preceded spinal cord symptoms in a patient with oligodendroglioma of the spinal cord. It is also the first reported case of oligodendrogliomatosis due to a cervical spinal cord oligodendroglioma with 1p and 19q deletions.

Gliosarcoma with melanocytic differentiation.

We present an unusual case of gliosarcoma containing numerous islands of well-differentiated melanocytes in a 65 year-old man. Melanocytic differentiation of medulloblastomas is well described, and it has also rarely been reported in low-grade glial neoplasms. Histologic features and immunophenotyping are helpful in differentiating divergent differentiation in a gliosarcoma from melanoma. To our knowledge, this is the first description of a gliosarcoma with melanocytic differentiation. Awareness of the phenomenon of melanocytic differentiation within primary neuroepithelial and glial neoplasms is important to prevent the misdiagnosis of these tumors such as metastatic melanoma or primary melanocytic neoplasms of the CNS.

Outcomes of surgery for resection of regions of symptomatic radiation injury after stereotactic radiosurgery for arteriovenous malformations.

OBJECTIVE: Although radiation injury after stereotactic radiosurgery (SRS), including radiation necrosis (RN), is often treated with surgical resection, detailed outcome data are lacking after resection of symptomatic radiation-injured regions with imaging characteristics suspicious for RN after SRS for arteriovenous malformations (AVM). We present outcomes in seven such patients. METHODS: We conducted a retrospective chart review of seven patients with AVMs of Spetzler-Martin Grades II (n = 1), III (n = 2), and IV (n = 4) who underwent helium ion, proton beam, or gamma knife SRS and required resection of RN-suspicious tissue 1 to 24 months after post-SRS symptom onset. Postoperative outcomes included Karnofsky Performance Scale (KPS) score and time to symptomatic improvement. RESULTS: Symptomatic improvement required at least 9 months in the three patients with large regions suspicious for RN (>or=4 cm), whereas of four patients with smaller regions (<4 cm), three showed improvement within 2 months (P < 0.05). The remaining patient, who showed no benefit, underwent resection 2 years after the onset of RN symptoms (compared with

A series of 397 peripheral neural sheath tumors: 30-year experience at Louisiana State University Health Sciences Center.

OBJECT: This is a retrospective review of 397 benign and malignant peripheral neural sheath tumors (PNSTs) that were surgically treated between 1969 and 1999 at the Louisiana State University Health Sciences Center (LSUHSC). The surgical techniques and adjunctive treatments are presented, the tumors are classified with respect to type and prevalence at each neuroanatomical location, and the management of malignant PNSTs is reviewed. METHODS: There were 361 benign PNSTs (91%). One hundred forty-one benign lesions were brachial plexus tumors: 54 schwannomas (38%) and 87 neurofibromas (62%), of which 55 (63%) were solitary neurofibromas and 32 (37%) were neurofibromatosis Type 1 (NF1)-associated neurofibromas. Among the brachial plexus lesions supraclavicular tumors predominated with 37 (69%) of 54 schwannomas; 34 (62%) of 55 solitary neurofibromas; and 19 (59%) of 32 NF1-associated neurofibromas. One hundred ten upper-extremity benign PNSTs consisted of 32 schwannomas (29%) and 78 neurofibromas (71%), of which 45 (58%) were sporadic neurofibromas and 33 (42%) were NF1-associated neurofibromas. Twenty-five benign PNSTs were removed from the pelvic plexus. Lower-extremity PNSTs included 32 schwannomas (38%) and 53 neurofibromas (62%), of which 31 were solitary neurofibromas and 22 were NF1-associated neurofibromas. There were 36 malignant PNSTs: 28 neurogenic sarcomas and eight other sarcomas (fibro-, spindle cell, synovial, and perineurial sarcomas). CONCLUSIONS: The majority of tumors were benign PNSTs from the brachial plexus region. Most of the benign PNSTs in all locations were neurofibromas, with sporadic neurofibromas predominating. Similar numbers of schwannomas were found in the upper and lower extremities, whereas neurofibromas were more prevalent in the upper extremities. Despite aggressive limb-ablation or limb-sparing surgery plus adjunctive therapy, malignant PNSTs continue to be associated with high morbidity and mortality rates.

A series of 146 peripheral non-neural sheath nerve tumors: 30-year experience at Louisiana State University Health Sciences Center.

OBJECT: This is a retrospective review of 146 surgically treated benign and malignant peripheral non-neural sheath tumors (PNNSTs). Tumor classifications with patient numbers, locations of benign PNNSTs, and surgical techniques and adjunctive treatments are presented. The results of a literature review regarding tumor frequencies are presented. METHODS: One hundred forty-six patients with 111 benign and 35 malignant PNNSTs were treated between 1969 and 1999 at the Louisiana State University Health Sciences Center (LSUHSC). The benign tumors included 33 ganglion cysts, 16 cases of localized hypertrophic neuropathy, 12 lipomas, 12 tumors of vascular origin, and 11 desmoid tumors. There were four each of lipofibrohamartomas, myositis ossificans, osteochondromas, and ganglioneuromas; two each of meningiomas, cystic hygromas, myoblastoma or granular cell tumors, triton tumors, and lymphangiomas; and one epidermoid cyst. The locations of benign PNNSTs were the following: 33 in the brachial plexus region, 39 in an upper extremity, one in the pelvic plexus, and 38 in a lower extremity. The malignant PNNSTs included 35 surgically treated carcinomas, 15 of which originated in the breast and nine in the lung. There were two melanomas metastatic to nerve and one tumor each that had metastasized from the bladder, rectum, skin, head and neck, and thyroid, and from a primary Ewing sarcoma. There was a single lymphoma that had metastasized to the radial nerve and one chordoma and one osteosarcoma, each of which had metastasized to the brachial plexus. CONCLUSIONS: There were more benign PNNSTs than malignant ones. Benign tumors were relatively equally distributed in the brachial plexus region and upper and lower extremities, with the exception of the pelvic plexus, which had only one tumor.