Enhancing gliotic cyst wall with microvascular proliferation adjacent to a meningioma.

Cystic meningiomas are uncommon. Contrast enhancement of the cyst wall of peritumoral cysts on radiological imaging is generally thought to indicate that the wall contains tumor cells. The authors present a patient with a peritumoral cyst that enhanced despite the absence of tumor cells. Histological analysis demonstrated a gliotic cyst wall with numerous microvascular proliferations (MVPs) adjacent to a mixed transitional and angiomatous/microcystic meningioma. Immunoreactivity for vascular endothelial growth factor (VEGF) and its receptor, flt-1, was observed in the endothelial cells of both intratumoral vessels and cyst wall MVPs. Immunoreactivity for tenascin-C was strongly observed within and around the vascular wall of MVPs and in gliotic tissue adjacent to the meningioma. These changes are unusual in the peritumoral brain parenchyma of a slow-growing convexity meningioma and the MVPs may account for the atypical contrast enhancement of the cyst wall despite the absence of tumor cells.

[Primitive neuroectodermal tumor arising 8 years after chemotherapy and radiotherapy for acute lymphoblastic leukemia: case report].

We report a case of primitive neuroectodermal tumor (PNET) arising 8 years after chemotherapy and radiotherapy for acute lymphoblastic leukemia. A 15-year-old boy with a history of acute lymphoblastic leukemia, at the age of 7, underwent chemotherapy and 14Gy of radiotherapy to the whole brain. He was admitted to our department due to the development of aphasia, right hemiparesis and generalized convulsive seizure. MRI showed an irregularly enhanced mass in the left frontal lobe. A gross total removal of the tumor was performed and histological examination showed it to be PNET. Postoperatively, the patient underwent 20Gy of radiotherapy to the whole brain and 42Gy of local radiotherapy. Follow-up MRI showed no evidence of recurrent tumor 4 months after the radiotherapy. This tumor was thought to be a secondary brain tumor arising in this survivor of childhood acute lymphoblastic leukemia and it is a rare complication of successful leukemia treatment.

Neurocutaneous melanosis associated with Dandy-Walker malformation and a meningohydroencephalocele. Case report.

Neurocutaneous melanosis and Dandy-Walker malformation are both forms of rare congenital neurodysplasia. Interestingly, 8 to 10% of patients with neurocutaneous melanosis also harbor an associated Dandy-Walker malformation, indicating that these developmental abnormalities share a common origin. The authors describe a case of neurocutaneous melanosis associated with Dandy-Walker malformation and an occipital meningohydroencephalocele with a giant melanotic nevus. Multiple congenital liver masses were also observed in the infant. The occipital nevus was totally excised, and ventriculoperitoneal and cyst-peritoneal shunts were created to prevent subsequent hydrocephalus. Findings in this case support the possibility that excessive melanocytes hinder normal mesenchymal development, causing Dandy-Walker malformation and an occipital meningocele.

[Gliomatosis cerebri: report of 3 cases and review of recent literatures].

Gliomatosis cerebri is a rare tumor of the central nervous system characterized by widespread diffuse infiltration of the brain and spinal cord by neoplastic glial cells. The diagnosis of gliomatosis cerebri with MR imaging remains difficult. We presented three interesting cases of gliomatosis cerebri. Case 1 showed transformation from type 1 gliomatosis cerebri to type 2. Case 2 showed that the initial thalamic lesion extended into brain stem, cerebellar hemisphere and right cerebral hemisphere. After radiation therapy, the right cerebral cortex demonstrated hyperintensity on T1- and hypointensity on T2-weighted image. These two cases did not demonstrate diffuse brain swelling or indistinctness of gray/white matter border on the first MR imaging. Case 3 showed two histological components of oligodendroglioma in the corpus callosum and astrocytoma in the cingulate gyrus. Case 3 improved in response to radiotherapy and chemotherapy using procarbazine/MCNU/vincristine (MVP). We also reviewed recent literatures.