Irina Mikolaenko

Multinodular and vacuolating neuronal tumors of the cerebrum: 10 cases of a distinctive seizure-associated lesion

We report 10 cases of a non‐neurocytic, purely neuronal tumor affecting adults. Situated in the cerebral hemispheres, with 7 of 10 confined to the temporal lobes, most presented with seizures as their principal clinical manifestations. On magnetic resosnance imaging (MRI), the tumors generally appeared solid and non‐contrast enhancing with minimal diffuse infiltration, edema, or mass effect. Six examples demonstrated internal nodularity. Microscopically, the tumor cells were largely distributed into discrete and coalescent nodules exhibiting varying degrees of matrix vacuolization, principally within the deep cortical ribbon and superficial subcortical white matter. Populating elements ranged from morphologically ambiguous to recognizably neuronal, with only two cases manifesting overt ganglion cell cytology. In all cases, tumor cells exhibited widespread nuclear immunolabeling for the HuC/HuD neuronal antigens, although expression of other neuronal markers, including synaptophysin, neurofilament and chromogranin was variable to absent. Tumor cells also failed to express GFAP, p53, IDH1 R132H, or CD34, although CD34‐labeling ramified neural elements were present in the adjoining cortex of seven cases. Molecular analysis in a subset of cases failed to reveal DNA copy number abnormalities or BRAF V600E mutation. Follow‐up data indicate that this unusual neuronal lesion behaves in benign, World Health Organization (WHO) grade I fashion and is amenable to surgical control.

Loss of cation-chloride cotransporter expression in preterm infants with white matter lesions: implications for the pathogenesis of epilepsy.

Epilepsy associated with preterm birth is often refractory to anticonvulsants. Children who are born preterm are also prone to cognitive delay and behavioral problems. Brains from these children often show diffuse abnormalities in cerebral circuitry that is likely caused by disrupted development during critical stages of cortical formation. To test the hypothesis that prenatal injury impairs the developmental switch of &ggr;-amino butyric acid (GABA)ergic synapses from excitatory to inhibitory, thereby disrupting cortical circuit formation and predisposing to epilepsy, we used immunohistochemistry to compare the expression of cation-chloride transporters that developmentally regulate postsynaptic GABAergic discharges in postmortem cerebral samples from infants born preterm with known white matter injury (n = 11) with that of controls with minimal white matter gliosis (n = 7). Controls showed the expected developmental expression of cation-chloride transporters NKCC1 and KCC2 and ofcalretinin, a marker of a GABAergic neuronal subpopulation. Samples from infants with white matter damage showed a significant loss of expression of both NKCC1 and KCC2 in subplate and white matter. By contrast, there were no significant differences in total cell number or glutamate transporter VGLUT1 expression. Together, these novel findings suggest a molecular mechanism involved in the disruption of a critical stage of cerebral circuit development after brain injury from preterm birth that may predispose to epilepsy.

Melanocytic tumor with GNA11 p.Q209L mutation mimicking a foramen magnum meningioma

Melanocytic tumors of the central nervous system arise from elanocytes normally found in the leptomeninges. They most comonly present as intradural-extramedullary lesions of the posterior ossa and cervical spine, but may occur throughout the neuraxis 1]. This group includes diffuse leptomeningeal melanocytosis and ocal tumors ranging from benign melanocytomas to malignant rimary CNS melanomas. Few tumors of intermediate grade (“atypcal” melanocytic tumors) have been reported [1]. Here we report n unusual intermediate-grade melanocytic tumor arising from he dura of the craniocervical junction. Its radiographic and gross ppearance were suggestive of a foramen magnum meningioma. Our ability to grade and treat CNS melanocytic tumors is limted by our poor understanding of their molecular derangements. here is some evidence that their pathogenesis resembles that of ther melanocytic neoplasms. In particular, uveal melanomas have een found to harbor frequent mutations of GNAQ [2] and GNA11 3], which encode components of two related G proteins. A recent

Isolated sixth cranial nerve palsy as the presenting symptom of a rapidly expanding ACTH positive pituitary adenoma: a case report

BackgroundPituitary adenoma may present with neuro-ophthalmic manifestations and, typically, rapid tumor expansion is the result of apoplexy. Herein, we present the first case of an isolated sixth cranial nerve palsy as initial feature of a rapidly expanding ACTH positive silent tumor without apoplexy.Case PresentationA 44 year old female with a history of sarcoidosis presented with an isolated sixth cranial nerve palsy as the initial clinical feature of a rapidly expanding ACTH positive silent pituitary adenoma. The patient underwent emergent transsphenoidal hypophysectomy for this rapidly progressive tumor and subsequently regained complete vision and ocular motility. Despite tumor extension into the cavernous sinus, the other cranial nerves were spared during the initial presentation.ConclusionsThis case illustrates the need to consider a rapidly growing pituitary tumor as a possibility when presented with a rapidly progressive ophthalmoplegia.

Suprasellar Hamartoma and Arachnoid Cyst

OBJECTIVE The differential diagnosis for suprasellar masses includes a variety of pathologies, ranging from stable and benign lesions to aggressive and malignant ones. We report a case of a suprasellar hamartoma associated with an arachnoid cyst and review the literature surrounding the topic. CASE DESCRIPTION A 32-year-old man who presented with headaches and nonspecific vision loss was found to have a cystic, calcified, and minimally contrast enhancing lesion of the suprasellar region. Intraoperative inspection revealed a discrete mass in the right side of suprasellar region that resembled normal brain completely enveloped by the basal arachnoid membranes including the membrane of Lillequist and was not connected to the brain. Fenestration and exploration of the cystic portion demonstrated a simple arachnoid cyst filled with what appeared to be cerebrospinal fluid. Given the adherence of the lesion to numerous perforating arteries arising from the posterior communicating artery, a biopsy with intraoperative confirmation was taken. Pathology was consistent with neuroglial tissue without evidence of neoplasia. CONCLUSIONS To our knowledge this is only the third case of an isolated suprasellar hamartoma described in the literature and the first of its kind to be associated with an arachnoid cyst.

Pelvic Ependymoma With Clinical Response to GnRH Analog Therapy: A Case Report With an Overview of Primary Extraneural Ependymomas.

Extraneural ependymomas are rare tumors that occur in sacrococcygeal, pelvic and extra pelvic regions. While sacrococcygeal extraneural ependymomas are equally distributed among males and females, pelvic and extra pelvic ependymomas have been exclusively reported in women, mainly of child bearing age. We present a case of extraneural, pelvic ependymoma that showed clinical response to GnRH therapy with its immunohistochemical and electron microscopic analysis, and an overview of primary extraneural ependymomas based on a review of all such cases published in English literature.

A 3-YEAR- OLD GIRL WITH ALTERED MENTAL STATUS, GAIT DIFFICULTY, AND VOMITING

We report a case of a 3-year-old girl with a 9-month history of focal neurologic finding and signs of increased intracranial pressure. Radiological imaging studies showed a minimally heterogeneous enhancing large tumor involving left parietal region and partly filling the left lateral ventricle. Microscopically, the tumor contained prominent small true rosettes set into areas of fibrillar neuropil-like matrix. Foci of cellular tumor with extensive apoptosis were present. The neuropil-like areas and true rosettes were positive for synaptophysin immunostain. The tumor was negative for GFAP and neurofilament protein immunostains. MIB-1 proliferation index was high focally approaching 80%.

Metameric thoracic lesion: report of a rare case and a guide to management

Metameric lesions of the spine are rare. The authors present a case of patient with a complex metameric vascular lesion of the thoracic spine and describe a management strategy for this entity.

Cystic choroid plexus papilloma in the cavum septum pellucidum.

A choroid plexus papilloma is a rare CNS neoplasm arising from the neuroepithelial lining of the choroid plexus. A third ventricular location of a choroid plexus papilloma is rare compared with the more common sites in the lateral and fourth ventricles. Cystic choroid plexus papilloma represents an infrequent subtype that may present diagnostic ambiguity. The authors present a case of cystic choroid plexus papilloma within a cavum septum pellucidum that radiographically mimicked neurocysticercosis.

Brain metastasis of Wilms tumor with diffuse anaplasia and complex cytogenetic phenotype in a child with neurofibromatosis Type 1

The authors report the first case of a Wilms tumor (WT) with diffuse anaplasia metastatic to the brain in a 13-year-old girl with a history of neurofibromatosis Type 1. At presentation, the metastatic tumor had radiological features that suggested a meningioma. Histologically it was characterized by striking anaplasia and features similar to the patients previously resected WT with diffuse anaplasia.